Power conversion device and its manufacturing method

Abstract

This invention relates to a power conversion device and a method for manufacturing the same. The power conversion device includes a power module, a cooling plate, and a cooler. The cooler has: a cooling flow path for refrigerant to flow along another side of the cooling plate; a first flow path hole that is spaced apart from the cooling flow path on the opposite side of a first side of the cooling flow path, closer to the power module side, and extends from a third side of the cooling flow path to a fourth side of the cooling flow path; a second flow path hole that is spaced apart from the cooling flow path on the opposite side of a second side of the cooling flow path, closer to the power module side, and extends from a third side of the cooling flow path to a fourth side of the cooling flow path; a first connecting portion connecting the cooling flow path to the first flow path hole; and a second connecting portion connecting the cooling flow path to the second flow path hole. When viewed in a direction perpendicular to the cooling plate, the power module is configured to overlap with at least a portion of the first flow path hole and the second flow path hole.

Description

Technical Field

[0001] This application relates to a power conversion device and a method for manufacturing the same. Background Technology

[0002] In electrified vehicles, specifically hybrid electric vehicles (HV), plug-in hybrid electric vehicles (PHV, PHEV), electric vehicles (EV), and fuel cell vehicles (FCV), electric drive motors are used. Electrified vehicles are equipped with power conversion devices such as inverters that drive the electric drive motors and converters that boost the battery voltage. The power conversion devices include power modules housing power semiconductors, coolers that cool the power modules, and capacitors. The coolers have flow paths for refrigerant to pass through.

[0003] In recent years, due to the trend towards smaller, higher-output, and lower-cost power conversion devices, the current and voltage flowing through power semiconductor chips have been increasing year by year. Furthermore, semiconductor chips account for a significant proportion of the cost of power conversion, thus requiring a reduction in their cost.

[0004] To reduce the cost of semiconductor chips, methods to improve the cooling capacity of semiconductor chips have been explored. For example, a cooler and a power module consisting of multiple components that cool both sides of a power module on which semiconductor chips are mounted have been disclosed (see, for example, Patent Document 1). In the disclosed configuration, a cooler integrated with the power module is used and is arranged together with capacitors within a hollow housing.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-109322 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In the aforementioned Patent Document 1, both sides of a power module on which semiconductor chips are mounted can be cooled. However, since multiple components are used to integrate the power module and the cooler, the positional relationship and size of the power module and the cooler are limited in terms of component configuration, thus making miniaturization difficult.

[0010] Furthermore, the cooler has limited flexibility in flow path configuration, and changes to the cooling of components other than the power module (such as capacitors) and the inflow and outflow of refrigerant are not easy. Therefore, changes to the flow path configuration require complex piping routes and consume design time and design discussion and revision time, making cost reduction relatively difficult.

[0011] Therefore, the purpose of this application is to obtain a power conversion device that is small in size and low in cost, with a high degree of freedom in the configuration of the power module and the cooler, as well as the configuration of the flow path of the cooler.

[0012] Technical means for solving technical problems

[0013] The power conversion device disclosed in this application includes: a power module, which is rectangular in shape, has power semiconductors, and has a bottom surface, a top surface, and four side surfaces; a cooling plate, which is flat, with one side of the cooling plate thermally connected to the bottom surface of the power module; and a cooler, which cools the cooling plate, the cooler including: a cooling flow path, which allows refrigerant to flow along another side of the cooling plate from a first side surface of the power module to a second side surface opposite to the first side surface; and a first flow path hole, which is spaced apart from the cooling flow path on the opposite side of the power module relative to the first side surface of the cooling flow path, and is located from the power module... The first side extends from the third side adjacent to the first side to the fourth side opposite to the third side; the second flow path hole is disposed at a distance from the cooling flow path on the opposite side of the power module side relative to the second side side of the cooling flow path, and extends from the third side side to the fourth side side; the first connecting portion connects the first side side portion of the cooling flow path to the first flow path hole; and the second connecting portion connects the second side side portion of the cooling flow path to the second flow path hole. When viewed in a direction perpendicular to one side of the cooling plate, the power module is disposed overlapping at least a portion of the first flow path hole and at least a portion of the second flow path hole.

[0014] Invention Effects

[0015] The power conversion device disclosed in this application includes a power module, a flat cooling plate with one side thermally connected to the bottom surface of the power module, and a cooler for cooling the cooling plate. The cooler has: a cooling flow path for refrigerant to flow along another side of the cooling plate; a first flow path hole and a second flow path hole spaced apart from the cooling flow path; a first connecting portion connecting the cooling flow path to the first flow path hole; and a second connecting portion connecting the cooling flow path to the second flow path hole. Viewed in a direction perpendicular to one side of the cooling plate, the power module is arranged overlapping at least a portion of the first flow path hole and at least a portion of the second flow path hole. Therefore, the projected area of ​​the cooler can be reduced, thus enabling miniaturization of the power conversion device. Furthermore, by placing the power module on the cooling plate, the degree of freedom in the arrangement of the power module and the cooler is increased, and it does not affect the degree of freedom in the arrangement of other components. Therefore, miniaturization of the power conversion device is easily achieved. In addition, the structure of the flow path of the cooler is relatively simple, thus increasing the degree of freedom in the arrangement of the flow path of the cooler and reducing the cost of the power conversion device. Attached Figure Description

[0016] Figure 1 This is a top view of the power conversion device according to Embodiment 1.

[0017] Figure 2 Is Figure 1 A cross-sectional view of the power conversion device cut off at section AA.

[0018] Figure 3 This is another top view of the power conversion device according to Embodiment 1.

[0019] Figure 4 Is Figure 3 A cross-sectional view of the power conversion device cut off at the BB section location.

[0020] Figure 5 Is Figure 3 A cross-sectional view of the power conversion device cut off at the CC section location.

[0021] Figure 6 Is Figure 3 A cross-sectional view of other power conversion devices cut off at the CC section location.

[0022] Figure 7 This is a diagram illustrating the manufacturing process of the power conversion device according to Embodiment 1.

[0023] Figure 8 Is Figure 1 A cross-sectional view of other power conversion devices cut off at the AA section location.

[0024] Figure 9 This is a top view of the power conversion device according to Embodiment 2.

[0025] Figure 10 Is Figure 9 A cross-sectional view of the power conversion device cut off at the DD section location.

[0026] Figure 11 This is a top view of the power conversion device according to Embodiment 3.

[0027] Figure 12 Is Figure 11 A cross-sectional view of the power conversion device cut off at the EE section location.

[0028] Figure 13 This is a top view of the power conversion device according to Embodiment 4.

[0029] Figure 14 Is Figure 13A cross-sectional view of the power conversion device cut off at the FF section location.

[0030] Figure 15 This is a cross-sectional view of the power conversion device according to Embodiment 5.

[0031] Figure 16 This is a side view of the power conversion device according to Embodiment 6.

[0032] Figure 17 Is Figure 16 A cross-sectional view of the power conversion device cut off at the GG section location.

[0033] Figure 18 This is a top view of the power conversion device according to Embodiment 7.

[0034] Figure 19 Is Figure 18 A cross-sectional view of the power conversion device cut off at the HH section location.

[0035] Figure 20 Is Figure 18 A cross-sectional view of the power conversion device cut off at the JJ section location.

[0036] Figure 21 Is Figure 18 A cross-sectional view of the power conversion device cut off at the KK section location.

[0037] Figure 22 Is Figure 18 A cross-sectional view of the power conversion device cut off at the HH section location.

[0038] Figure 23 Is Figure 18 A cross-sectional view of the power conversion device cut off at the JJ section location.

[0039] Figure 24 This is a top view of the power conversion device according to Embodiment 8.

[0040] Figure 25 Is Figure 24 A cross-sectional view of the power conversion device cut off at the LL section location.

[0041] Figure 26 Is Figure 24 A cross-sectional view of the power conversion device cut off at the MM section location.

[0042] Figure 27 Is Figure 24 A cross-sectional view of the power conversion device cut off at the NN section location.

[0043] Figure 28 Is Figure 24 A cross-sectional view of the power conversion device cut off at the MM section location.

[0044] Figure 29 Is Figure 24 A cross-sectional view of other power conversion devices cut off at the LL section location. Detailed Implementation

[0045] Hereinafter, the power conversion device according to the embodiments of this application will be described based on the accompanying drawings. Furthermore, identical or equivalent components and parts will be labeled with the same reference numerals in the drawings.

[0046] Implementation method 1.

[0047] Figure 1 This is a top view of the power conversion device 1 according to Embodiment 1, showing the device with the cover 6 and control board 8 removed. Figure 2 Is Figure 1 The diagram shows a cross-sectional view of the power conversion device 1 cut off at section AA, including the cover 6 and the control board 8. Figure 3 This is another top view of the power conversion device 1, from... Figure 1 A diagram showing the cooler 4 and outer wall component 20 after removing the internal parts. Figure 4 Is Figure 3 A cross-sectional view of the power conversion device 1 cut off at the BB section location. Figure 5 Is Figure 3 A cross-sectional view of the power conversion device 1 cut off at the CC section position. Figure 6 Is Figure 3 A cross-sectional view of the other power conversion device 1 cut off at the CC section location. Figure 7 This is a diagram illustrating the manufacturing process of the power conversion device 1 according to Embodiment 1. Figure 8 Is Figure 1 A cross-sectional view of the other power conversion device 1 cut off at the AA section location. Figures 3 to 6 The arrow shown is an arrow indicating the direction of refrigerant flow (flow direction 10). The power converter 1 is a device with circuitry for controlling power, converting input current from DC to AC, from AC to DC, or converting input voltage to different voltages.

[0048] <Component Structure of Power Conversion Device 1>

[0049] like Figure 2As shown, the power conversion device 1 includes a power module 2, a capacitor 3, a cooler 4, a cooling plate 5, a control board 8, and a cover 6. The component forming the flow path of the cooler 4 is integrally formed with the outer wall component 20 surrounding the capacitor 3 and other components. Furthermore, the openings related to the electrical input and output of the power conversion device 1 are not shown in the figures of this embodiment. The power module 2, capacitor 3, control board 8, and other low-heat-generating components (not shown) are housed within the space enclosed by the cooler 4 and the cover 6, and they are electrically connected.

[0050] The power module 2 is a cuboid shape with a bottom surface 2a, a top surface 2b, and four sides (first side 2c, second side 2d, third side 2e, and fourth side 2f), and contains power semiconductors (not shown). In this embodiment, in the power module 2, as... Figure 1 As shown, the three power modules 2 are arranged side-by-side with the same orientation in a direction parallel to the first side 2c. The length of one side of the first side 2c, obtained by adding the lengths of the long sides of the three power modules 2 along their respective long sides, is longer than the length of one side of the third side 2e adjacent to the first side 2c. The first side 2c is the side parallel to the normal direction of the side. Figure 1 The arrow X1 side is the same as the arrow Y1 side on the third side 2e. Similarly, the second side 2d is... Figure 1 The arrow X2 side, the fourth side 2f side is the arrow Y2 side, and the bottom side 2a side is... Figure 2 The top surface 2b is on the side of arrow Z1, and the bottom surface 2a of all power modules 2 is thermally connected to one surface 5b of the cooling plate 5. The number of power modules 2 is not limited to this; it can be one or more than three. The power module 2 includes power terminals 2g and control terminals 2h exposed to the outside. The power terminals 2g are connected to the capacitor 3, and the control terminals 2h are connected to the control substrate 8. In addition, the power module 2 may, for example, have one or more power semiconductors mounted and disposed on a substrate disposed internally. The number of substrates is not limited to one; it may also be configured such that one or more power semiconductors are mounted on each of multiple substrates.

[0051] The capacitor 3 is electrically connected to the power module 2 and is disposed on the first side 2c side, the second side 2d side opposite to the first side 2c side, or the top surface 2b side of the power module 2. In this embodiment, the capacitor 3 is formed as a cuboid having a bottom surface 3a, a top surface 3b, and four sides (first side 3c, second side 3d, third side 3e, and fourth side 3f). The capacitor 3 is disposed on the first side 2c side of the power module 2, with one side of the capacitor 3 facing the first side 2c side of the power module 2. The shape of the capacitor 3 is not limited to a cuboid shape and can also be cylindrical. The capacitor 3 is a component in which multiple component elements are housed in a capacitor housing, and heat-dissipating resin is injected into the gaps between the component elements and the capacitor housing. The capacitor 3 has a power terminal 3g exposed from the top surface 3b to the outside, and the power terminal 3g is connected to the power terminal 2g of the power module 2.

[0052] In this embodiment, the second side 3d of the capacitor 3 is arranged opposite to the cooler 4, and the outer wall member 20 surrounds the first side 3c, the third side 3e, the fourth side 3f, and the bottom surface 3a of the capacitor 3. A gap is provided between the outer wall member 20 and the four sides of the capacitor 3, and this gap is filled with a heat-dissipating resin 7 (e.g., potting material). By filling this gap with the heat-dissipating resin 7, the capacitor 3 can be cooled efficiently, thus effectively protecting the capacitor 3, which has relatively weak heat resistance. The outer wall member 20 abuts against the bottom surface 3a of the capacitor 3; for example, the capacitor 3 is fastened to the bottom surface 3a by screws. The capacitor 3 can be positioned on the second side 2d side of the power module 2, with the long side of the capacitor 3 facing the second side 2d side of the power module 2. Furthermore, as... Figure 8 As shown, the heat-dissipating resin 7 can be configured to fill the space between the outer wall member 20 and the bottom surface 3a of the capacitor 3, rather than in the gaps between the outer wall member 20 and the four sides of the capacitor 3. Since the amount of heat-dissipating resin 7 used can be reduced, the cost of the heat-dissipating resin 7 can be lowered. Furthermore, if the heat-dissipating resin 7 on the bottom surface 3a alone is insufficient for cooling the capacitor 3, the heat-dissipating resin 7 can be placed in the gaps between the outer wall member 20 and the four sides of the capacitor 3 to cool the capacitor 3.

[0053] The control board 8 outputs a signal to control the operation of the power module 2, thereby controlling the operation of the power module 2. The control board 8 is equipped with multiple control components 8a, and control terminals 2h are electrically connected to the control board 8. The control board 8 is configured opposite to the power module 2 and the capacitor 3. This configuration enables miniaturization of the power conversion device 1 and achieves low inductance. The power terminals 2g of the power module 2 and 3g of the capacitor 3 are electrically connected between the power module 2, the capacitor 3, and the control board 8. This connection minimizes the electrical wiring between the power module 2 and the capacitor 3, achieving low inductance in the power conversion device 1. The connection between the power terminals 2g and 3g can be achieved, for example, by soldering, screw fastening, or laser welding. By directly connecting the power terminals 2g and 3g via soldering, screw fastening, or laser welding without using other components, the electrical wiring can be shortened, allowing for a low-inductance connection. Because the connection can be made with low inductance, the chip size of the power semiconductor can be reduced, achieving cost reduction of the power semiconductor.

[0054] The cooling plate 5 is flat, with one side 5b thermally connected to the bottom surface 2a of the power module 2. The other side 5c of the cooling plate 5 is joined to the outer periphery 4a1 of the cooling flow path 4a (described later) via a metal connection (e.g., friction stir joining). Cooling fins 5a are provided on the other side 5c of the cooling plate 5. Multiple cooling fins 5a protrude in a direction away from the other side 5c of the cooling plate 5. By providing cooling fins 5a, the power module 2 can be cooled efficiently. The cooling plate 5 and cooling fins 5a are formed of a metal with high thermal conductivity, such as aluminum. By narrowing the spacing between the cooling fins 5a, the contact area between the refrigerant and the cooling fins 5a increases, thereby improving the heat dissipation of the power module 2. The narrowed spacing of the cooling fins 5a can be formed, for example, by forging. On the other hand, if the spacing between the cooling fins 5a is narrowed to increase the filling density, the cross-sectional area of ​​the flow path through which the refrigerant flows is reduced. If the cross-sectional area of ​​the flow path is reduced, the fluid resistance of the refrigerant increases. Therefore, it is necessary to improve the performance of the water pump that powers the refrigerant flow, which leads to increased costs. In this embodiment, as described later, the refrigerant flows in a direction perpendicular to the first side 2c, that is, in the direction of the short side of the three power modules 2 as a whole, thus suppressing the increase in fluid resistance.

[0055] <Cooler 4>

[0056] The main part of this application, the cooler 4, will be described. The cooler 4 cools the cooling plate 5, the power module 2, and the capacitor 3. The refrigerant used is, for example, water or liquid ethylene glycol. The cooler 4 has a flow path through which the refrigerant flows. The flow path is formed by a cooling flow path 4a, a first flow path hole 4b, a second flow path hole 4c, a first connecting portion 4d, and a second connecting portion 4e. The cooler 4 is formed, for example, by die casting of aluminum.

[0057] Cooling flow path 4a is a flow path through which refrigerant flows from the first side 2c side of power module 2 to the second side 2d side along the other side 5c of cooling plate 5. Cooling flow path 4a is the portion between the other side 5c of cooling plate 5 and the flow path 4a2 of cooler 4. First flow path hole 4b is a flow path that is spaced apart from cooling flow path 4a on the opposite side of power module 2 compared to the portion on the first side 2c side of cooling flow path 4a, and extends from the third side 2e side adjacent to the first side 2c side of power module 2 to the fourth side 2f side opposite to the third side 2e side. Second flow path hole 4c is a flow path that is spaced apart from cooling flow path 4a on the opposite side of power module 2 compared to the portion on the second side 2d side of cooling flow path 4a, and extends from the third side 2e side to the fourth side 2f side. First connecting portion 4d is a flow path that connects the portion on the first side 2c side of cooling flow path 4a to the first flow path hole 4b. The second connecting part 4e is a flow path that connects the portion of the second side 2d in the cooling flow path 4a to the second flow path hole 4c.

[0058] A refrigerant inlet / outlet is provided on the third side 2e or the fourth side 2f of the first flow path hole 4b, and a refrigerant inlet / outlet is provided on the third side 2e or the fourth side 2f of the second flow path hole 4c. For example... Figure 5 As shown, the refrigerant flows into the outlet via, for example, through a press-fitted pipe 9. The openings on the third side 2e or the fourth side 2f of the first flow path hole 4b and the second flow path hole 4c, where the pipe 9 is not installed, are blocked by sealing bolts 11. In this embodiment, as... Figure 3 As shown, a refrigerant inlet, i.e., pipe 9, is provided on the third side 2e of the first flow path hole 4b, and a refrigerant outlet, i.e., pipe 9, is provided on the third side 2e of the second flow path hole 4c. Furthermore, the openings on the fourth side 2f of the first flow path hole 4b and the fourth side 2f of the second flow path hole 4c are blocked by sealing bolts 11. The location of the refrigerant inflow and outflow can be freely selected and set on either the third side 2e or the fourth side 2f, thus allowing for the selection of a flow path corresponding to the location of the power conversion device 1, increasing the flexibility of flow path configuration. By providing pipe 9, refrigerant can easily flow into and out of the cooler 4. By providing sealing bolts 11, the flow path can be easily blocked.

[0059] The first flow path 4b and the second flow path 4c rectify the refrigerant. The first flow path 4b rectifies the refrigerant, allowing it to flow parallel and uniformly through the cooling fins 5a. Therefore, when multiple power modules 2 are present, the cooling capacity of each power module 2 can be unified, and the temperature of the power modules 2 becomes uniform. Consequently, the electrical characteristics of the power modules 2, which have temperature characteristics, become uniform among the power modules 2, and the switching controllability of the power modules 2 becomes good.

[0060] In this embodiment, the first flow path hole 4b and the second flow path hole 4c are provided as through holes, and one of the openings is blocked by a sealing bolt 11. However, it can also be configured so that the first flow path hole 4b and the second flow path hole 4c are not through holes. When the flow path holes are not through holes, the sealing bolt 11 is not required, and therefore, the power conversion device 1 can be manufactured at a lower cost. In this embodiment, the pipe 9 is constructed separately from the cooler 4, but the pipe 9 can also be formed by die casting integrally with the cooler 4. When the pipe 9 is integrally provided with the cooler 4, the pipe 9 is not required, and therefore, the power conversion device 1 can be manufactured at a lower cost.

[0061] The cross-section perpendicular to the direction in which one or both of the first flow path hole 4b and the second flow path hole 4c extend is circular. In this embodiment, as... Figure 4 As shown, the cross-sectional shape of both the first flow path hole 4b and the second flow path hole 4c is circular. When the cross-sectional shape of one or both of the first flow path hole 4b and the second flow path hole 4c is circular, the formation of the flow path hole is easier during manufacturing, which can improve the production efficiency of the power conversion device 1. This is especially true when the cooler 4 is manufactured by die casting, which can further improve the production efficiency of the power conversion device 1. In addition, the cross-sectional shape of the flow path hole is not limited to a circle, and can also be other shapes such as a quadrilateral.

[0062] The size of the cross-section perpendicular to the direction in which one or both of the first flow path hole 4b and the second flow path hole 4c extend can differ in the portion between the third and fourth side surfaces. For example, as... Figure 6 As shown, the flow path hole 4b can be constructed by reducing the cross-sectional shape of the middle portion (stepped portion 4b1) of the first flow path hole 4b. When the flow path hole is constructed in this way using a step, the position of the cooling flow path 4a can be lowered, thus enabling miniaturization of the power conversion device 1. Furthermore, by changing the shape of at least a portion of the flow path hole to a quadrilateral or other shape, the limitations on component placement or flow path placement caused by the flow path hole can be alleviated, thus increasing the freedom of component placement. Alternatively, other structures, such as providing a taper to the flow path hole, can also be constructed.

[0063] like Figure 4As shown, the refrigerant flows in the flow direction 10 in the order of first flow path orifice 4b, first connecting portion 4d, cooling flow path 4a, second connecting portion 4e, and second flow path orifice 4c. The flow direction 10 can be reversed. In this embodiment, as... Figure 3 As shown, the pipe 9 installed in the first flow path hole 4b serves as the refrigerant inlet, and the pipe 9 installed in the second flow path hole 4c serves as the refrigerant outlet, but this is not a limitation. The inlet and outlet can be opposite, or the refrigerant can flow into and out from the fourth side 2f. Figure 2 As shown, when capacitor 3 is disposed on the first side 2c of power module 2 and refrigerant flows into the first flow path hole 4b, the capacitor 3 can be cooled by the low-temperature refrigerant flowing in, thus effectively protecting the capacitor 3 which has weak heat resistance.

[0064] Viewed from a direction perpendicular to a surface 5b of the cooling plate 5, the power module 2 is configured to overlap with at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c. By configuring the power module 2 in this way, which overlaps with at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c, the projected area of ​​the cooler 4 can be reduced compared to the case where the flow path hole (which serves as the rectifier) ​​and the cooling flow path 4a are located on the same plane, without reducing the area of ​​the cooling power module 2. Since the projected area of ​​the cooler 4 can be reduced, the power conversion device 1 can be miniaturized. Furthermore, since the power module 2, the cooler 4, and the capacitor 3 are separate, and the power module 2 is positioned on the cooling plate 5, the arrangement of the power module 2, the cooler 4, and the capacitor 3 has a high degree of freedom and does not affect the arrangement freedom of other components. Therefore, the scope of discussion for miniaturizing the power conversion device 1 is broadened, and the power conversion device 1 can be easily miniaturized. Furthermore, the flow path structure and shape of the cooler 4 are relatively simple, thus allowing for a high degree of freedom in the configuration of the flow path and easy modification of the refrigerant inlet and outlet positions. Because the flow path structure and shape of the cooler 4 are relatively simple, the power conversion device 1 can be reduced in cost.

[0065] The length of the first side 2c, obtained by adding the lengths of the long sides of the three power modules 2, is longer than the length of the third side 2e. The refrigerant flows from the first side 2c to the second side 2d in the cooling flow path 4a. Therefore, the refrigerant flows through the cooling flow path 4a along the short side of the entire power module 2. By making the refrigerant flow along the short side of the power module 2, the flow path is shortened, suppressing the increase in fluid resistance. Since the increase in fluid resistance is suppressed, the spacing of the cooling fins 5a can be narrowed, and the filling rate of the cooling fins 5a can be increased. If the filling rate of the cooling fins 5a is increased, the heat dissipation performance of the power module 2 can be improved.

[0066] In this embodiment, such as Figure 2 As shown, cooling fins 5a are only provided on a portion of the other side 5c of the cooling plate 5, where the power module 2 is disposed on the opposite side and opposite to the flow path 4a2. The arrangement of cooling fins 5a is not limited to this; they can also be further arranged on the portion of the other side 5c of the cooling plate 5 opposite to the first connecting portion 4d. By further arranging the cooling fins 5a, the refrigerant can collide perpendicularly with the added cooling fins 5a. By making the refrigerant collide perpendicularly with the cooling fins 5a, the cooling capacity can be improved through a collision jet. Since the chip size of the power semiconductor can be reduced by improving the cooling capacity, the power conversion device 1 can be miniaturized.

[0067] <Manufacturing Method of Power Conversion Device 1>

[0068] Regarding the manufacturing method of power conversion device 1, using Figure 7 The following explanation will focus on the construction of the cooler 4. The main part of this application is the structure of the cooler 4; therefore, the explanation will focus on the manufacturing method of the cooler 4. The manufacturing method of the power conversion device 1 includes a component preparation step (S11), a cooler manufacturing step (S12), and a cooling flow path formation step (S13).

[0069] The component preparation process involves preparing a power module 2, which has a bottom surface 3a, a top surface 3b, and four sides (first side 3c, second side 3d, third side 3e, and fourth side 3f) formed into a cuboid shape and contains power semiconductors, as well as a flat cooling plate 5. When the cooling plate 5 has multiple cooling fins 5a, in the component preparation process, the spacing between the multiple cooling fins 5a protruding in the direction away from another surface 5c is narrowed by forging and formed on the cooling plate 5. The manufacturing method of the cooling fins 5a is not limited to this; they can also be manufactured by machining, etc. However, when the cooling fins 5a are manufactured by forging, the spacing between the multiple cooling fins 5a can be narrowed to form narrow-pitch cooling fins 5a. By forming narrow-pitch cooling fins 5a, a higher cooling capacity of the power module 2 can be ensured. The cooling fins 5a are manufactured, for example, with a fin width of 1.5 mm and a fin pitch of 2.5 mm.

[0070] The cooler manufacturing process is the process of manufacturing cooler 4. In its assembled state, cooler 4 has a cooling flow path 4a, a first flow path hole 4b, a second flow path hole 4c, a first connecting portion 4d, and a second connecting portion 4e. In the assembled state, viewed from a direction perpendicular to a surface 5b of the cooling plate 5, the power module 2 is arranged overlapping at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c. Cooler 4 is manufactured by die casting. The material of cooler 4 is, for example, aluminum. The first flow path hole 4b and the second flow path hole 4c are formed using a drawing core. A portion of the cooling flow path 4a, the first connecting portion 4d, and the second connecting portion 4e are formed using a fixed mold or a movable mold. By using a die-casting drawing core and a fixed or movable mold, the portions constituting the flow path of cooler 4 can be easily formed. The formation of the flow path portions does not require complex processing, thus enabling the power conversion device 1 to be manufactured at low cost. The structure and shape of the flow path are relatively simple, thus increasing the freedom of configuration of the flow path in cooler 4. In addition, when the first flow path hole 4b and the second flow path hole 4c are provided in the form of through holes, a sealing bolt 11 is provided in the opening of one of the first flow path hole 4b and the second flow path hole 4c, and the opening is blocked by the sealing bolt 11.

[0071] The first flow path hole 4b and the second flow path hole 4c can be formed by abutting the mandrel from both the third side 2e and the fourth side 2f. When the first flow path hole 4b and the second flow path hole 4c are formed by abutting the mandrel, the length of the mandrel can be reduced compared to forming the flow path hole from one side using the mandrel. Since the length of the mandrel can be reduced, the manufacturability based on die casting can be improved. Furthermore, compared to forming the flow path hole from one side using the mandrel, the reduction in the cross-sectional area of ​​the flow path hole caused by the mandrel's slope can be mitigated.

[0072] The cooling flow path forming process involves thermally connecting the bottom surface 2a of the power module 2 to one surface 5b of the cooling plate 5, and joining the other surface 5c of the cooling plate 5 to the outer peripheral portion 4a1 of the cooling flow path 4a. The joining of the other surface 5c of the cooling plate 5 to the outer peripheral portion 4a1 of the cooling flow path 4a is achieved through metal bonding (e.g., friction stir bonding). The bonding method is not limited to metal bonding; it can also be achieved through screw locking. When joining them through metal bonding, compared to a screw-locked structure, insulation distance is ensured and component configuration limitations are mitigated. By joining the cooling plate 5 to a portion of the flow path manufactured by die casting, a refrigerant flow path can be formed, thus enabling low-cost and easy flow path formation. Instead of directly mounting the power module 2 to the cooler 4, the power module 2 is mounted to the cooler 4 via the cooling plate 5, which has a higher degree of freedom in manufacturing. Therefore, the shape of the cooling fins 5a provided on the cooling plate 5 has a higher degree of freedom, thus easily and cost-effectively ensuring a high cooling capacity for the power module 2.

[0073] As described above, in the power conversion device 1 according to Embodiment 1, when viewed in a direction perpendicular to a surface 5b of the cooling plate 5, the power module 2 is arranged overlapping at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c. Therefore, the projected area of ​​the cooler 4 can be reduced without reducing the area of ​​the cooling power module 2. Since the projected area of ​​the cooler 4 can be reduced, the power conversion device 1 can be miniaturized. Furthermore, by arranging the power module 2 on the cooling plate 5, the degree of freedom in the arrangement of the power module 2 and the cooler 4 is high, and it does not affect the degree of freedom in the arrangement of other components. Therefore, the scope of discussion on miniaturization of the power conversion device 1 is broadened, and the power conversion device 1 can be easily miniaturized. In addition, the structure and shape of the flow path of the cooler 4 are relatively simple, thus increasing the degree of freedom in the arrangement of the flow path of the cooler 4, and the position of the refrigerant inlet and outlet can be easily changed. Multiple power modules 2 are arranged in a direction parallel to the first side 2c. The length of the first side 2c, obtained by adding the lengths of the long sides of the power modules 2, is longer than the length of the third side 2e. In this case, the refrigerant flows from the first side 2c to the second side 2d in the cooling flow path 4a. Therefore, the refrigerant flows through the short side of the entire power module 2 in the cooling flow path 4a, thus shortening the flow path and suppressing the increase of fluid resistance.

[0074] When the cooling plate 5 has cooling fins 5a, the power module 2 can be cooled efficiently. Furthermore, when the cross-sectional shape perpendicular to the direction extending from one or both of the first flow path hole 4b and the second flow path hole 4c is circular, the flow path holes are easier to form during manufacturing, improving the production efficiency of the power conversion device 1. Moreover, when the size of the cross-sectional shape perpendicular to the direction extending from one or both of the first flow path hole 4b and the second flow path hole 4c differs between the third and fourth side sides, and a step is used to form part of the first flow path hole 4b, the position of the cooling flow path 4a can be lowered, thus enabling miniaturization of the power conversion device 1.

[0075] When the control board 8 is arranged opposite to the power module 2 and the capacitor 3, the power conversion device 1 can be miniaturized, and low inductance can be achieved. Furthermore, when the power terminals 2g of the power module 2 and 3g of the capacitor 3 are electrically connected between the power module 2, the capacitor 3, and the control board 8, the electrical wiring between the power module 2 and the capacitor 3 can be minimized, further reducing the inductance of the power conversion device 1. Additionally, when the space between the outer wall member 20 and the bottom surface 3a of the capacitor 3 is filled with heat-dissipating resin 7, the amount of heat-dissipating resin 7 used can be reduced, lowering costs and efficiently cooling the capacitor 3. Furthermore, when the gap between the outer wall member 20 and the side surface of the capacitor 3 is filled with heat-dissipating resin 7, efficient cooling of the capacitor 3 is achieved. Moreover, when the capacitor 3 is positioned on the first side surface 2c of the power module 2 and refrigerant flows into the first flow path hole 4b, the capacitor 3 can be cooled using refrigerant flowing in at low temperatures, thus effectively protecting the capacitor 3, which has relatively low heat resistance.

[0076] The first flow path hole 4b has a refrigerant inlet / outlet on either the third side 2e or the fourth side 2f, and the second flow path hole 4c has a refrigerant inlet / outlet on either the third side 2e or the fourth side 2f. In this case, the location of the refrigerant inlet / outlet can be freely chosen to be on either the third side 2e or the fourth side 2f. Therefore, a flow path corresponding to the location of the power conversion device 1 can be selected, increasing the flexibility of flow path configuration. Furthermore, when a pipe 9 is installed at the refrigerant inlet / outlet, refrigerant can easily flow into and out of the cooler 4. Additionally, the flow path can be easily blocked by using the sealing bolt 11 to seal the openings on either the third side 2e or the fourth side 2f of the first and second flow path holes 4b and 4c.

[0077] By die casting, a core is used to form the first flow path hole 4b and the second flow path hole 4c, and a fixed mold or a movable mold is used to form the portion of the cooling flow path 4a, the first connecting portion 4d, and the second connecting portion 4e. In this case, the portion constituting the flow path of the cooler 4 can be easily formed. The formation of the flow path portion does not require complex processing, so the power conversion device 1 can be manufactured at low cost. The structure and shape of the flow path are relatively simple, thus increasing the freedom of configuration of the flow path of the cooler 4. In addition, by forging, the spacing between the multiple cooling fins 5a protruding in the direction away from the other face 5c is narrowed and formed on the cooling plate 5, thus ensuring a high cooling capacity of the power module 2. Furthermore, when the other face 5c of the cooling plate 5 is joined to the outer peripheral portion 4a1 of the cooling flow path 4a by metal bonding, compared with the screw-locked structure, the insulation distance is ensured and the restrictions on component configuration are alleviated.

[0078] Implementation method 2.

[0079] The power conversion device 1 according to Embodiment 2 will be described. Figure 9 This is a top view of the power conversion device 1 according to Embodiment 2, showing the cooler 4 and outer wall component 20 after removing internal components. Figure 10 Is Figure 9 The figures show a cross-sectional view of the power conversion device 1 after being cut at the DD section position. The power module 2 is not shown in these figures, but it is arranged in the same position as in Embodiment 1. The power conversion device 1 in Embodiment 2 is configured to have a third flow path hole 4f in addition to the power conversion device 1 shown in Embodiment 1.

[0080] The cooler 4 has a third flow path 4f, which connects to the second flow path 4c and extends from the second flow path 4c to the second side 2d (arrow X2 side) or the opposite side of the cooling flow path 4a (arrow Z1 side). A refrigerant inlet / outlet is provided on the third side 2e (arrow Y1 side) or the fourth side 2f (arrow Y2 side) of the first flow path 4b. A refrigerant inlet / outlet is also provided on the side of the third flow path 4f opposite to the second flow path 4c side. In this embodiment, the third side 2e (arrow Y1 side) of the first flow path 4b is the refrigerant inlet / outlet, and a pipe 9 is installed at the refrigerant inlet / outlet. The third flow path 4f extends to the second side 2d (arrow X2 side), and the second side 2d, opposite to the second flow path 4c side, is the refrigerant inlet / outlet, and a pipe 9 is installed at the refrigerant inlet / outlet. Furthermore, an example is shown here with a pipe 9 installed at the refrigerant inlet and outlet, but an air valve to vent air from the flow path through which the refrigerant flows can also be installed. The refrigerant flows into the first flow path orifice 4b, and flows within the flow path in the flow direction 10. The flow direction 10 can be reversed.

[0081] In this embodiment, the capacitor 3 ( Figure 9 The third flow path 4f is disposed on the first side 2c side (arrow X1 side) of the power module 2, and therefore, the third flow path 4f is disposed on the second flow path 4c side. When the capacitor 3 is disposed on the second side 2d side (arrow X2 side) of the power module 2, the third flow path 4f can also be disposed on the first flow path 4b side.

[0082] As described above, in the power conversion device 1 according to Embodiment 2, a third flow path 4f extends from the second flow path 4c to the side opposite to the second side 2d or the cooling flow path 4a. Therefore, a refrigerant inlet / outlet is provided on a side different from the third side 2e or the fourth side 2f, thus increasing the flexibility in configuring the flow path of the cooler 4. This increased flexibility in configuring the flow path of the cooler 4 allows for easy modification of the refrigerant inlet / outlet position, reducing design time. When an air valve is installed at the refrigerant inlet / outlet, air in the refrigerant flow path can be removed, thus suppressing the decrease in cooling performance, vibration, and impact caused by uneven refrigerant flow due to air in the flow path. Furthermore, it prevents problems such as damage to the flow path.

[0083] Implementation method 3.

[0084] The power conversion device 1 according to Embodiment 3 will be described. Figure 11 This is a top view of the power conversion device 1 according to Embodiment 3, showing the cooler 4 and outer wall component 20 after removing internal components. Figure 12 Is Figure 11 The figures show a cross-sectional view of the power conversion device 1 after it has been cut at the EE section. The power module 2 is not shown in these figures, but it is arranged in the same position as in Embodiment 1. The power conversion device 1 in Embodiment 3 is configured to include a partition 12 that separates the flow paths, in addition to the power conversion device 1 shown in Embodiment 1.

[0085] The first flow path hole 4b and the first connecting portion 4d are separated at a position between the third side 2e (arrow Y1 side) and the fourth side 2f (arrow Y2 side). The cooling flow path 4a is separated at a position corresponding to the separation of the first flow path hole 4b and the first connecting portion 4d at a position between the third side 2e (arrow Y1 side) and the fourth side 2f (arrow Y2 side). The portion separating the first flow path hole 4b, the first connecting portion 4d, and the cooling flow path 4a is the partition portion 12. Refrigerant inlet and outlet ports for refrigerant inflow and outflow are provided on the third side 2e (arrow Y1 side) and the fourth side 2f (arrow Y2 side) of the first flow path hole 4b. The third side 2e (arrow Y1 side) and the fourth side 2f (arrow Y2 side) of the second flow path hole 4c are, for example, blocked by a sealing bolt 11.

[0086] Refrigerant flows into the first flow path orifice 4b, and flows within the flow path in the flow direction 10. By providing the partition 12, thus... Figure 11As shown, the refrigerant flows in the following order: first flow path orifice 4b, first connecting portion 4d, cooling flow path 4a, second connecting portion 4e, second flow path orifice 4c, second connecting portion 4e, cooling flow path 4a, first connecting portion 4d, and first flow path orifice 4b. Cooling flow path 4a is divided into two parts by partition 12, in which the refrigerant flows in opposite directions. The first connecting portion 4d is as follows... Figure 12 As shown, the partition 12 is divided into two parts, in which the refrigerant flows in opposite directions.

[0087] As described above, in the power conversion device 1 according to Embodiment 3, the first flow path hole 4b and the first connecting portion 4d are separated at the position between the third side 2e and the fourth side 2f, and the cooling flow path 4a is separated at the position between the third side 2e and the fourth side 2f corresponding to the separation position of the first flow path hole 4b and the first connecting portion 4d. Therefore, part of the cooling flow path 4a of the cooling power module 2 is divided, and thus, the cooling capacity of the power module 2 and the pressure loss in the refrigerant flow path can be easily adjusted.

[0088] Implementation method 4.

[0089] The power conversion device 1 according to Embodiment 4 will be described. Figure 13 This is a top view of the power conversion device 1 according to Embodiment 4, showing the cooler 4 and outer wall member 20 after removing internal components. Figure 14 Is Figure 13 The figures show a cross-sectional view of the power conversion device 1 after it has been cut off at the FF section position. The power module 2 is not shown in these figures, but it is arranged in the same position as in Embodiment 1. The power conversion device 1 in Embodiment 4 is configured to include a partition 13 that separates the flow paths, in addition to the power conversion device 1 shown in Embodiment 1.

[0090] The cooling flow path 4a, the first connecting portion 4d, and the second connecting portion 4e are separated at multiple locations between the third side 2e (arrow Y1 side) and the fourth side 2f (arrow Y2 side) along the direction of refrigerant flow. The portion separating the cooling flow path 4a, the first connecting portion 4d, and the second connecting portion 4e is the partition portion 13. A refrigerant inlet / outlet is provided on the third side 2e (arrow Y1 side) or the fourth side 2f (arrow Y2 side) of the first flow path hole 4b, and a refrigerant inlet / outlet is provided on the third side 2e (arrow Y1 side) or the fourth side 2f (arrow Y2 side) of the second flow path hole 4c. In this embodiment, as... Figure 13As shown, a refrigerant inlet, i.e., pipe 9, is provided on the third side 2e (arrow Y1 side) of the first flow path hole 4b, and a refrigerant outlet, i.e., pipe 9, is provided on the third side 2e (arrow Y1 side) of the second flow path hole 4c. Furthermore, the openings on the fourth side 2f (arrow Y2 side) of the first flow path hole 4b and the fourth side 2f (arrow Y2 side) of the second flow path hole 4c are blocked by sealing bolts 11.

[0091] Refrigerant flows into the first flow path orifice 4b and flows within the flow path in the flow direction 10. The cooling flow path 4a is divided into three parts by the partition 13. By providing the partition 13, the refrigerant flows in the order of the first flow path orifice 4b, the first connecting part 4d, the three cooling flow paths 4a, the second connecting part 4e, and the second flow path orifice 4c. In this embodiment, three power modules 2 are included. Figure 13 (shown as dashed lines in the diagram), and forms three cooling flow paths 4a corresponding to each power module 2, but the structure of the cooling flow path 4a is not limited to this. It can be configured to provide one cooling flow path 4a for multiple power modules 2.

[0092] As described above, in the power conversion device 1 according to Embodiment 4, the cooling flow path 4a, the first connecting portion 4d, and the second connecting portion 4e are separated at multiple locations between the third side surface 2e and the fourth side surface 2f along the direction of refrigerant flow. Therefore, the cooling flow path 4a is divided according to the projected area of ​​the power module 2, thus eliminating unnecessary portions of the cooling flow path 4a. Since unnecessary portions of the cooling flow path 4a can be eliminated, the refrigerant flow rate in the cooling flow path 4a can be increased, thereby improving the cooling capacity of the power module 2. Furthermore, the cooling fins 5a provided in the unnecessary portions of the cooling flow path 4a can be removed, thus reducing the pressure loss of the cooling flow path 4a. Since the pressure loss of the cooling flow path 4a can be reduced, the cooling fins 5a can be provided with a narrower spacing corresponding to the amount of pressure loss reduction. By providing the cooling fins 5a with a narrower spacing, the cooling capacity of the power module 2 can be further improved. Furthermore, the cooling fins 5a that are located in the unused cooling flow path 4a can be removed, thus reducing the manufacturing cost of the cooling plate 5.

[0093] Implementation method 5.

[0094] The power conversion device 1 according to Embodiment 5 will be described. Figure 15 This is a cross-sectional view of the power conversion device 1, which is in conjunction with... Figure 1 The diagram shows the power conversion device 1 cut off at the same position as the AA section. The power conversion device 1 in Embodiment 5 is configured to include a relative power module 14, etc., in addition to the power conversion device 1 shown in Embodiment 1.

[0095] The power conversion device 1 includes a relative power module 14, a relative cooling plate 15, and a relative control substrate 16. The relative power module 14 is a cuboid with a bottom surface 14a, a top surface 14b, and four sides (first side 14c, second side 14d, third side 14d, and fourth side 16), and contains power semiconductors internally. The third and fourth sides are... Figure 15 Not shown in the figures. The relative power module 14 includes power terminals 14g and control terminals 14h exposed to the outside. The power terminals 14g are connected to the capacitor 3, and the control terminals 14h are connected to the relative control substrate 16. The relative cooling plate 15 is flat, with one side 15b thermally connected to the bottom surface 14a of the relative power module 14. The other side 5c of the cooling plate 5 and the other side 15c of the relative cooling plate 15 are arranged opposite to each other, sandwiching the cooler 4. The first side 2c of the power module 2 and the first side 14c of the relative power module 14 are arranged on the same side. The relative cooling plate 15 has cooling fins 15a on its other side 15c.

[0096] The relative control board 16 outputs signals to control the operation of the relative power module 14, thereby controlling the operation of the relative power module 14. The relative control board 16 is equipped with multiple control components 16a, and control terminals 14h are electrically connected to the relative control board 16. The relative control board 16 is configured opposite to the relative power module 14 and the capacitor 3. The power terminals 14g of the relative power module 14 and 3g of the capacitor 3 are electrically connected between the relative power module 14, the capacitor 3, and the relative control board 16.

[0097] The cooler 4 has a relative cooling flow path 4g, a third connecting portion 4h, and a fourth connecting portion 4i. The relative cooling flow path 4g is a flow path through which refrigerant flows along the other side 15c of the relative cooling plate 15 from the side of the first side 14c of the relative power module 14 to the side of the second side 14d opposite to the first side 14c. The third connecting portion 4h is a flow path that connects the portion of the relative cooling flow path 4g on the side of the first side 14c (arrow X1 side) to the first flow path hole 4b. The fourth connecting portion 4i is a flow path that connects the portion of the relative cooling flow path 4g on the side of the second side 14d (arrow X2 side) to the second flow path hole 4c. Viewed in a direction perpendicular to the other side 15c of the relative cooling plate 15, the relative power module 14 is configured to overlap at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c. The power conversion device 1 is... Figure 15 The cooler 4 has a cover 6 on both the arrow Z1 side and the arrow Z2 side. Therefore, the cooler 4 can be manufactured with both the arrow Z1 side and the arrow Z2 side open. Thus, similar to the manufacturing method shown in Embodiment 1, the part constituting the flow path can be easily formed using a die-casting core and a fixed mold or a movable mold.

[0098] As shown above, in the power conversion device 1 according to Embodiment 5, the cooler 4 is arranged opposite to the other side 5c of the cooling plate 5 and the other side 15c of the opposite cooling plate 15, sandwiching it. Viewed in a direction perpendicular to the other side 15c of the opposite cooling plate 15, the opposite power module 14 overlaps with at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c. Therefore, the projected area of ​​the cooler 4 can be reduced without reducing the area used to cool the opposite power module 14. Since the projected area of ​​the cooler 4 can be reduced, the power conversion device 1 can be miniaturized. The power module 2 and the opposite power module 14 are arranged overlapping and sandwiching the cooler 4, thus reducing the projected area of ​​the power conversion device 1 and enabling miniaturization of the power conversion device 1.

[0099] Implementation method 6.

[0100] The power conversion device 1 according to Embodiment 6 will be described. Figure 16 This is a side view of the power conversion device 1 according to Embodiment 6, showing the device with the cover 6 and control board 8 removed. Figure 17 Is Figure 16 A cross-sectional view of the power conversion device 1 after being cut at the GG section position. The power conversion device 1 according to Embodiment 6 is configured such that the capacitor 3 is arranged in a different position than that in Embodiment 1.

[0101] Capacitor 3 is disposed on the top surface 2b side of power module 2 (on the side of arrow Z2), with one face of capacitor 3 facing the top surface 2b side of power module 2 along its long side. Viewed perpendicularly to a face 5b of cooling plate 5, power module 2, capacitor 3, and at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c are arranged overlapping. Power conversion device 1... Figure 17 The cooler 4 has a cover 6 on both the arrow Z2 side and the arrow X2 side. Therefore, the cooler 4 can be manufactured with both the arrow Z2 side and the arrow X2 side open. Thus, similar to the manufacturing method shown in Embodiment 1, the part constituting the flow path can be easily formed using a die-casting core and a fixed mold or a movable mold.

[0102] As described above, in the power conversion device 1 according to Embodiment 6, when viewed in a direction perpendicular to one surface 5b of the cooling plate 5, the power module 2, capacitor 3, and at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c are arranged overlappingly. Therefore, the projected area of ​​the power conversion device 1 can be reduced, and the power conversion device 1 can be miniaturized. Furthermore, compared to the above embodiment, the capacitor 3 and the power module 2 can be arranged closer together, thus shortening the electrical wiring between the power module 2 and the capacitor 3. Since the electrical wiring between the power module 2 and the capacitor 3 is shortened, low inductance of the power conversion device 1 can be achieved. Because low inductance can be achieved, the chip size of the power semiconductor can be reduced, and the cost of the power semiconductor can be reduced.

[0103] Implementation method 7.

[0104] The power conversion device 1 according to Embodiment 7 will be described. Figure 18 This is a top view of the power conversion device 1 according to Embodiment 7, showing the device with the cover 6 and control board 8 removed. Figure 19 Is Figure 18 A cross-sectional view of the power conversion device 1 after being cut at the HH section position. Figure 20 Is Figure 18 A cross-sectional view of the power conversion device 1 after being cut at the JJ section position. Figure 21 Is Figure 18 A cross-sectional view of the power conversion device 1 after being cut at the KK section position. Figure 22 Is Figure 18 The diagram shows a cross-sectional view of the power conversion device 1 after it has been cut at the HH section position, and a view of the cooler 4 and the outer wall component 20 after the internal components have been removed. Figure 23 Is Figure 18 The cross-sectional view of the power conversion device 1 after being cut at the JJ section position is a diagram of the cooler 4 and the outer wall member 20 after removing the internal components. The power conversion device 1 according to Embodiment 7 is configured such that the power module 2 is housed in the housing 17 without a cooling plate.

[0105] The power conversion device 1 includes a power module 2, a housing 17 for housing the power module 2, a cooler 4 for cooling the housing 17, a capacitor 3, a control board 8, and a cover 6. The power module 2 is a cuboid with a bottom surface 2a, a top surface 2b, and four sides (first side 2c, second side 2d, third side 2e, and fourth side 2f), and contains power semiconductors (not shown). The power module 2 has a power terminal 2g and a control terminal 2h on the fourth side 2f. In this embodiment, in the power module 2, as... Figure 18As shown, three power modules 2 are arranged side-by-side with the same orientation in a direction parallel to the first side 2c. A capacitor 3 is disposed on the first side 2c of the power module 2, with one face of the capacitor 3 facing the first side 2c of the power module 2 along its long side. The first side 2c is the side parallel to the normal direction of the side surface. Figure 18 The arrow X1 side. Similarly, the second side 2d side is the arrow X2 side, the bottom side 2a side is the arrow Y2 side, and the top side 2b side is the arrow Y1 side. Furthermore, the third side 2e side is... Figure 19 The arrow Z1 side is the fourth side, and the 2f side is the arrow Z2 side.

[0106] The housing 17 has an opening through which power terminals 2g and control terminals 2h are exposed to the outside. Power terminals 2g are connected to power terminals 3g of capacitor 3, and control terminals 2h are connected to control substrate 8. The housing 17 is made of a metal with high thermal conductivity (e.g., aluminum). A heat-dissipating resin (not shown) is injected into the gap between the power module 2 and the housing 17, making the power module 2 and housing 17 integral. The housing 17 has multiple cooling fins 17a on the outer surface of the wall opposite the top surface 2b of the power module 2 and on the outer surface of the wall opposite the bottom surface 2a of the power module 2. It is also possible to configure the housing 17 without providing cooling fins 17a on its outer surface, but by providing cooling fins 17a, the power module 2 can be cooled efficiently. In this embodiment, a structure with three power modules 2 is shown, but the number of power modules 2 is not limited to three.

[0107] The cooler 4 has a cooling flow path 4a3 on the top side, a cooling flow path 4a4 on the bottom side, a first flow path hole 4b, a second flow path hole 4c, a first connecting part 4d, and a second connecting part 4e. The cooling flow path 4a3 on the top side is such that refrigerant flows along the outer surface of the wall of the housing 17 opposite to the top surface 2b of the power module 2, from the first side 2c side of the power module 2 to the second side 2d side opposite to the first side 2c. The cooling flow path 4a4 on the bottom side is such that refrigerant flows along the outer surface of the wall of the housing 17 opposite to the bottom surface 2a of the power module 2, from the first side 2c side of the power module 2 to the second side 2d side. The first flow path 4b is a flow path that is spaced apart from the cooling flow path 4a3 on the top side and the cooling flow path 4a4 on the bottom side relative to the first side 2c of the cooling flow path 4a3 on the top side and the cooling flow path 4a4 on the bottom side, and extends from the top side 2b to the bottom side 2a.

[0108] The second flow path 4c is a flow path that, relative to the portion on the second side 2d of the cooling flow path 4a3 on the top surface and the cooling flow path 4a4 on the bottom surface, is spaced apart from the cooling flow path 4a3 on the top surface and the cooling flow path 4a4 on the bottom surface, and extends from the top surface 2b to the bottom surface 2a. The first connecting portion 4d is a flow path that connects the portion on the first side 2c of the cooling flow path 4a3 on the top surface and the cooling flow path 4a4 on the bottom surface to the first flow path 4b. The second connecting portion 4e is a flow path that connects the portion on the second side 2d of the cooling flow path 4a3 on the top surface and the cooling flow path 4a4 on the bottom surface to the second flow path 4c.

[0109] The refrigerant flows in the flow direction 10 in the following order: first flow path 4b, first connecting portion 4d, cooling flow path 4a3 on the top side or cooling flow path 4a4 on the bottom side, second connecting portion 4e, and second flow path 4c. The housing 17 is connected to the cooler 4 by a side surface 17b with a sealing structure around the opening, thus sealing the flow path through which the refrigerant flows. The sealing structure is, for example, an O-ring. Viewed in a direction perpendicular to the third side surface 2e of the power module 2, the power module 2 is arranged overlapping at least a portion of the first flow path 4b and at least a portion of the second flow path 4c. Furthermore, similar to the manufacturing method shown in Embodiment 1, the portion constituting the flow path of the cooler 4 can be easily formed by a die-casting core and a fixed or movable mold.

[0110] As described above, in the power conversion device 1 according to Embodiment 7, when viewed in a direction perpendicular to the third side surface 2e of the power module 2, the power module 2 is arranged overlapping at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c, thus reducing the projected area of ​​the cooler 4. Since the projected area of ​​the cooler 4 can be reduced, the power conversion device 1 can be miniaturized. Furthermore, the cooler 4 includes a cooling flow path 4a3 on the top side and a cooling flow path 4a4 on the bottom side, thus cooling the power module 2 from both sides, thereby improving the cooling capacity of the power module 2. Because the cooling capacity of the power module 2 is improved, the power semiconductor chip has a thermal margin, thus reducing the chip size of the power semiconductor and achieving cost reduction of the power semiconductor. The housing 17 has multiple cooling fins 17a on the outer surface of the wall opposite the top surface 2b of the power module 2 and the outer surface of the wall opposite the bottom surface 2a of the power module 2, in which case the power module 2 can be cooled efficiently.

[0111] Implementation method 8.

[0112] The power conversion device 1 according to Embodiment 8 will be described. Figure 24 This is a top view of the power conversion device 1 according to Embodiment 8, showing the device with the cover 6 and control board 8 removed. Figure 25Is Figure 24 A cross-sectional view of the power conversion device 1 after being cut off at the LL section position. Figure 26 Is Figure 24 A cross-sectional view of the power conversion device 1 after being cut at the MM section position. Figure 27 Is Figure 24 A cross-sectional view of the power conversion device 1 after being cut off at the NN section position. Figure 28 Is Figure 24 The diagram shows a cross-sectional view of the power conversion device 1 after it has been cut off at the MM section position, and a view of the cooler 4 and outer wall component 20 after removing the internal components. Figure 29 Is Figure 24 A cross-sectional view of the other power conversion device 1 after being cut off at the LL section position. The power conversion device 1 according to Embodiment 8 is configured as a power module 2 housed in the housing 17 in a different configuration than that of Embodiment 7.

[0113] The power conversion device 1 includes a power module 2, a housing 17 for housing the power module 2, a cooler 4 for cooling the housing 17, a capacitor 3, a control board 8, and a cover 6. The power module 2 is a cuboid with a bottom surface 2a, a top surface 2b, and four sides (first side 2c, second side 2d, third side 2e, and fourth side 2f), and contains power semiconductors (not shown). The power module 2 has a power terminal 2g and a control terminal 2h on the second side 2d. In this embodiment, in the power module 2, as... Figure 24 As shown, three power modules 2 are arranged side-by-side with the same orientation in a direction parallel to the top surface 2b. A capacitor 3 is disposed on the top surface 2b side of the power modules 2, with one face of the capacitor 3 facing the top surface 2b side of the power modules 2 along its long side. The top surface 2b side is the side parallel to the normal direction of the top surface. Figure 23 The arrow X1 side. Similarly, the bottom surface 2a side is the arrow X2 side, the third side 2e side is the arrow Y1 side, and the fourth side 2f side is the arrow Y2 side. Furthermore, the first side 2c side is... Figure 24 The arrow Z1 side is the second side, and the second side 2d side is the arrow Z2 side.

[0114] The housing 17 has an opening through which power terminals 2g and control terminals 2h are exposed to the outside. Power terminals 2g are connected to power terminals 3g of capacitor 3, and control terminals 2h are connected to control substrate 8. The housing 17 has multiple cooling fins 17a on the outer surface of the wall opposite the top surface 2b of power module 2 and on the outer surface of the wall opposite the bottom surface 2a of power module 2. Alternatively, the cooling fins 17a may not be provided on the outer surface of the housing 17, but by providing cooling fins 17a, the power module 2 can be cooled efficiently. In this embodiment, a structure with three power modules 2 is shown, but the number of power modules 2 is not limited to three.

[0115] The cooler 4 has a cooling flow path 4a3 on the top side, a cooling flow path 4a4 on the bottom side, a first flow path hole 4b, and a second flow path hole 4c. The cooling flow path 4a3 on the top side is such that refrigerant flows along the outer surface of the wall of the housing 17 opposite to the top surface 2b of the power module 2, from the first side 2c side of the power module 2 to the second side 2d side opposite to the first side 2c. The cooling flow path 4a4 on the bottom side is such that refrigerant flows along the outer surface of the wall of the housing 17 opposite to the bottom surface 2a of the power module 2, from the first side 2c side of the power module 2 to the second side 2d side. The first flow path hole 4b is such that it is disposed on the first side 2c side of the housing 17, extends from the third side 2e side adjacent to the first side 2c to the fourth side 2f side opposite to the third side 2e, and connects to the cooling flow path 4a3 on the top side and the cooling flow path 4a4 on the bottom side. The second flow path 4c is a flow path that is disposed on the second side 2d side of the housing 17, extends from the third side 2e side to the fourth side 2f side, and connects to the cooling flow path 4a3 on the top side and the cooling flow path 4a4 on the bottom side.

[0116] The refrigerant flows in the flow direction 10 in the order of first flow path 4b, cooling flow path 4a3 on the top side or cooling flow path 4a4 on the bottom side, and second flow path 4c. The housing 17 is connected to the cooler 4 by a side 17b with a sealing structure around the opening, sealing the flow path of the refrigerant. The sealing structure is, for example, an O-ring. Viewed in a direction perpendicular to the first side 2c of the power module 2, the power module 2 is configured to overlap with at least a portion of the first flow path 4b and at least a portion of the second flow path 4c.

[0117] In this embodiment, such as Figure 25 As shown, the portions of housing 17 adjacent to the first flow path hole 4b and the portions of housing 17 adjacent to the second flow path hole 4c are also provided with cooling fins 17a. However, the structure is not limited to this, such as... Figure 29 As shown, the cooling fins 17a of the portion of housing 17 adjacent to the first flow path hole 4b and the portion of housing 17 adjacent to the second flow path hole 4c can be spaced out. With the cooling fins 17a spaced out, the refrigerant can be rectified, allowing the refrigerant to flow side-by-side and uniformly through the cooling fins 17a. Therefore, when multiple power modules 2 are provided, the cooling capacity of each power module 2 can be unified, and the temperature of the power modules 2 becomes uniform. Consequently, the electrical characteristics of the power modules 2 with temperature characteristics become uniform among the power modules 2, and the switching controllability of the power modules 2 becomes good. Furthermore, it can suppress the decrease in cooling performance, vibration, and impact caused by uneven refrigerant flow. In addition, it can prevent problems such as damage to the flow path.

[0118] Capacitor 3 can be disposed on the bottom surface 2a side of power module 2. By disposing of capacitor 3 on either the bottom surface 2a side or the top surface 2b side of power module 2, capacitor 3 can be disposed close to power module 2, thereby shortening the electrical wiring between power module 2 and capacitor 3. Because the electrical wiring between power module 2 and capacitor 3 is shortened, low inductance of power conversion device 1 can be achieved. Since low inductance is achieved, the chip size of power semiconductors can be reduced, and the cost of power semiconductors can be lowered.

[0119] As described above, in the power conversion device 1 according to Embodiment 8, when viewed in a direction perpendicular to the first side surface 2c of the power module 2, the power module 2 is arranged overlapping at least a portion of the first flow path hole 4b and at least a portion of the second flow path hole 4c, thus reducing the projected area of ​​the cooler 4. Since the projected area of ​​the cooler 4 can be reduced, the power conversion device 1 can be miniaturized. Furthermore, the cooler 4 includes a cooling flow path 4a3 on the top surface and a cooling flow path 4a4 on the bottom surface, thus cooling the power module 2 from both sides, thereby improving the cooling capacity of the power module 2. Because the cooling capacity of the power module 2 is improved, the power semiconductor chip has thermal margin, thus reducing the chip size of the power semiconductor and achieving cost reduction of the power semiconductor.

[0120] Furthermore, the cooling flow path 4a3 on the top side and the cooling flow path 4a4 on the bottom side are arranged to overlap with the first flow path hole 4b and the second flow path hole 4c. In this case, the volume of the first flow path hole 4b and the second flow path hole 4c can be reduced, thus enabling the power conversion device 1 to be miniaturized.

[0121] Furthermore, although this application describes various exemplary implementation methods and embodiments, the various features, methods and functions described in one or more implementation methods are not limited to specific implementation methods, but can also be applied to implementation methods individually, or in various combinations to be applied to implementation methods.

[0122] Therefore, it can be assumed that numerous variations not illustrated are also included within the scope of the technology disclosed in this application. For example, this includes cases where at least one constituent element is modified, added to, or omitted, and cases where at least one constituent element is extracted and combined with constituent elements of other embodiments.

[0123] Label Explanation

[0124] 1 Power conversion device

[0125] 2 Power Modules

[0126] 2a Bottom surface

[0127] 2b Top surface

[0128] 2c First side

[0129] 2d Second Side View

[0130] 2e Third side

[0131] 2f Fourth side

[0132] 2g power terminal

[0133] 2h control terminal

[0134] 3 Capacitors

[0135] 3a Bottom surface

[0136] 3b Top surface

[0137] 3c First side

[0138] 3D Second Side View

[0139] 3e Third side

[0140] 3f Fourth side

[0141] 3G power terminals

[0142] 4. Cooler

[0143] 4a cooling flow path

[0144] 4a1 Peripheral part

[0145] 4a2 flow road surface

[0146] Cooling flow path on the top side of 4a3

[0147] Cooling flow path on the bottom side of 4a4

[0148] 4b First flow path

[0149] 4b1 Stepped Section

[0150] 4c Second flow path hole

[0151] 4d First Linkage

[0152] 4e Second Link

[0153] 4f Third Flowpath

[0154] 4g relative cooling flow path

[0155] 4h Third Connecting Section

[0156] 4i Fourth Link

[0157] 5. Cooling plate

[0158] 5a Cooling fins

[0159] 5b One side

[0160] 5c Another side

[0161] 6 lids

[0162] 7. Heat dissipation resin

[0163] 8. Control board

[0164] 8a Control Components

[0165] 9 pipes

[0166] 10. Flow direction

[0167] 11 Sealing bolts

[0168] 12. Divider

[0169] 13. Divider

[0170] 14 Relative Power Module

[0171] 14a Bottom

[0172] 14b Top surface

[0173] 14c First side

[0174] 14d Second side view

[0175] 14g power terminal

[0176] 14h control terminal

[0177] 15 Relative cooling plate

[0178] 15a Cooling fins

[0179] 15b One side

[0180] 15c Another side

[0181] 16 Relative control board

[0182] 16a Control Components

[0183] 17. Casing

[0184] 17a Cooling fins

[0185] 17b Side View

[0186] 20. External wall components

Claims

1. A power conversion device, characterized in that, include: The power module is rectangular in shape, has power semiconductors, and has a bottom surface, a top surface, and four sides; A cooling plate, which is flat, has one side thermally connected to the bottom surface of the power module; as well as A cooler that cools the cooling plate. The cooler includes: A cooling flow path is provided for the refrigerant to flow along the other side of the cooling plate from the first side of the power module to the second side opposite to the first side; A first flow path hole is disposed spaced apart from the cooling flow path on the opposite side of the power module side relative to the first side side of the cooling flow path, and extends from a third side side adjacent to the first side side of the power module to a fourth side side opposite to the third side side. The second flow path hole is disposed at a distance from the cooling flow path on the opposite side of the power module side relative to the second side side of the cooling flow path, and extends from the third side side to the fourth side side; A first connecting portion, which connects the portion of the first side of the cooling flow path to the first flow path hole; and The second connecting part connects the portion of the second side of the cooling flow path to the second flow path hole. Viewed in a direction perpendicular to one side of the cooling plate, the power module is configured to overlap with at least a portion of both the first flow path hole and at least a portion of the second flow path hole. The power conversion device includes a plurality of power modules, the bottom surfaces of which are thermally connected to one side of the cooling plate, and are arranged side-by-side with the power modules in the same orientation as the power modules in a direction parallel to the first side surface. The length of the first side of the plurality of power modules is longer than the length of the third side.

2. The power conversion device as described in claim 1, characterized in that, Cooling fins are present on the other side of the cooling plate.

3. The power conversion device as described in claim 1, characterized in that, Cooling fins are present on the other side of the cooling plate.

4. The power conversion device according to any one of claims 1 to 3, characterized in that, The cross-section perpendicular to the extension direction of one or both of the first flow path holes and the second flow path holes is circular.

5. The power conversion device according to any one of claims 1 to 3, characterized in that, The size of the cross-section perpendicular to the extension direction of one or both of the first and second flow paths differs in the portion between the third and fourth side sides.

6. The power conversion device according to any one of claims 1 to 3, characterized in that, include: A capacitor electrically connected to the power module and disposed on the first side, the second side, or the top surface of the power module; and a control board that controls the operation of the power module. The control board, which is electrically connected to the power module, is configured opposite to the power module and the capacitor.

7. The power conversion device as described in claim 6, characterized in that, Power terminals exposed from the power module and power terminals exposed from the capacitor are electrically connected between the power module and the capacitor and the control board.

8. The power conversion device as described in claim 6, characterized in that, The capacitor is formed in the shape of a cuboid with a bottom surface, a top surface, and four sides. The capacitor is disposed on either the first or second side of the power module, with the second side of the capacitor disposed opposite to the cooler. The component forming the flow path of the cooler is integrally formed with the outer wall component surrounding the first side, third side, fourth side, and bottom surface of the capacitor. A heat-dissipating resin is filled between the outer wall component and the bottom surface of the capacitor.

9. The power conversion device as described in claim 7, characterized in that, The capacitor is formed in the shape of a cuboid with a bottom surface, a top surface, and four sides. The capacitor is disposed on either the first or second side of the power module, with the second side of the capacitor disposed opposite to the cooler. The component forming the flow path of the cooler is integrally formed with the outer wall component surrounding the first side, third side, fourth side, and bottom surface of the capacitor. A heat-dissipating resin is filled between the outer wall component and the bottom surface of the capacitor.

10. The power conversion device as claimed in claim 6, characterized in that, The capacitor is formed in the shape of a cuboid with a bottom surface, a top surface, and four sides. The capacitor is disposed on either the first or second side of the power module, with the second side of the capacitor disposed opposite to the cooler. The component forming the flow path of the cooler is integrally formed with the outer wall component surrounding the first side, third side, fourth side, and bottom surface of the capacitor. A gap is provided between the outer wall component and the four sides of the capacitor, and the gap is filled with heat-dissipating resin. The outer wall component abuts against the bottom surface of the capacitor.

11. The power conversion device as claimed in claim 7, characterized in that, The capacitor is formed in the shape of a cuboid with a bottom surface, a top surface, and four sides. The capacitor is disposed on either the first or second side of the power module, with the second side of the capacitor disposed opposite to the cooler. The component forming the flow path of the cooler is integrally formed with the outer wall component surrounding the first side, third side, fourth side, and bottom surface of the capacitor. A gap is provided between the outer wall component and the four sides of the capacitor, and the gap is filled with heat-dissipating resin. The outer wall component abuts against the bottom surface of the capacitor.

12. The power conversion device as claimed in claim 6, characterized in that, The capacitor is disposed on the first side of the power module. The refrigerant flows into the first flow path orifice.

13. The power conversion device according to any one of claims 1 to 3, characterized in that, A refrigerant inlet / outlet is provided on the third or fourth side of the first flow path hole for refrigerant to flow in and out. A refrigerant inlet / outlet is provided on the third or fourth side of the second flow path hole for refrigerant to flow in and out.

14. The power conversion device according to any one of claims 1 to 3, characterized in that, The cooler has a third flow path orifice connected to the second flow path orifice, extending from the second flow path orifice to the second side or the opposite side of the cooling flow path. A refrigerant inlet / outlet is provided on the third or fourth side of the first flow path hole for refrigerant to flow in and out. A refrigerant inlet / outlet is provided on the side of the third flow path hole opposite to the side of the second flow path hole for refrigerant to flow in and out.

15. The power conversion device according to any one of claims 1 to 3, characterized in that, The first flow path hole and the first connecting portion are separated at a position between the third side surface and the fourth side surface. The cooling flow path is divided at a position between the third side and the fourth side, corresponding to the separation between the first flow path hole and the first connecting portion. The first flow path hole has a refrigerant inlet / outlet on the third and fourth side sides for refrigerant to flow in and out.

16. The power conversion device as claimed in claim 13, characterized in that, The cooling flow path, the first connecting portion, and the second connecting portion are separated at multiple locations between the third side and the fourth side along the direction of refrigerant flow.

17. The power conversion device as claimed in claim 13, characterized in that, The refrigerant inlet and outlet are equipped with pipes.

18. The power conversion device as claimed in claim 14, characterized in that, The refrigerant inlet and outlet are equipped with pipes.

19. The power conversion device as claimed in claim 15, characterized in that, The refrigerant inlet and outlet are equipped with pipes.

20. The power conversion device as claimed in claim 17, characterized in that, The openings on the third or fourth side of the first and second flow paths, where no pipes are installed, are blocked by sealing bolts.

21. The power conversion device as claimed in claim 18, characterized in that, The openings on the third or fourth side of the first and second flow paths, where no pipes are installed, are blocked by sealing bolts.

22. The power conversion device as claimed in claim 19, characterized in that, The openings on the third or fourth side of the first and second flow paths, where no pipes are installed, are blocked by sealing bolts.

23. The power conversion device as claimed in claim 1, characterized in that, include: A relative power module, which is rectangular in shape, has power semiconductors, and has a bottom surface, a top surface, and four side surfaces; as well as The relative cooling plate is flat, and one side of the relative cooling plate is thermally connected to the bottom surface of the relative power module. The other side of the cooling plate is positioned opposite to the other side of the opposing cooling plate, sandwiching the cooler. The first side of the power module is disposed on the same side as the first side of the opposing power module. The cooler includes: a relative cooling flow path for refrigerant to flow along the other side of the relative cooling plate from the first side of the relative power module to the second side opposite to the first side; and a third connection portion connecting the portion of the relative cooling flow path on the first side to the first flow path hole. And a fourth connecting portion, which connects the portion of the second side of the relative cooling flow path to the second flow path hole. Viewed in a direction perpendicular to the other side of the opposing cooling plate, the opposing power module is configured to overlap with at least a portion of the first flow path hole and at least a portion of the second flow path hole.

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