Power conversion device

Abstract

A power conversion device includes a power module that converts direct-current power into alternating-current power; a substrate that arranges the power module, includes a direct-current path that transmits the direct-current power to the power module, has a first surface and a second surface that faces the first surface, and has a plurality of main flow path holes that penetrate from the first surface to the second surface; and a flow path forming body that covers at least a portion of the first surface and the second surface of the substrate in a manner of covering the plurality of main flow path holes, forms a flow path of a refrigerant that cools the power module, and the plurality of main flow path holes are arranged at a position that crosses the direct-current path, and the refrigerant moves from the first surface to the second surface through the main flow path holes.

Description

Technical Field

[0001] This invention relates to an electric power conversion device. Background Technology

[0002] In recent years, there has been a trend towards increasing the electrical energy that power conversion devices need to convert. However, the overall requirements for automobiles to be smaller and lighter have suppressed the increase in the size and weight of power conversion devices. Furthermore, compared with industrial power conversion devices, automotive power conversion devices are required to operate in environments with large temperature variations, thus requiring power conversion devices that can be placed in high-temperature environments and maintain high reliability.

[0003] To perform power conversion, the semiconductor modules constituting the upper and lower arms of the inverter circuit need to repeatedly switch between off and on states. During these switching operations, the transient current flowing through the upper and lower arms becomes a cause of surge voltage due to the parasitic inductance of the wiring. Consequently, the losses of the semiconductor modules increase, and the chip temperature of the semiconductor modules rises. Therefore, reducing the inductance that contributes to the temperature rise and improving cooling performance are important issues in order to suppress the temperature rise.

[0004] Patent Document 1 discloses a power conversion device comprising a semiconductor module having a series circuit of an upper arm circuit and a lower arm circuit constituting an inverter circuit, and a smoothing capacitor for smoothing the DC voltage supplied to the semiconductor module. The semiconductor module comprises multiple semiconductor modules, each including a first power semiconductor element constituting the upper arm circuit, a second power semiconductor element constituting the lower arm circuit, a first conductor plate disposed on one side of the first power semiconductor element and connected to one electrode of the first power semiconductor element via solder, a second conductor plate disposed on the other side of the first power semiconductor element and connected to the other electrode of the first power semiconductor element via solder, a third conductor plate disposed on one side of the second power semiconductor element and connected to one electrode of the second power semiconductor element via solder, and a third conductor plate disposed on the second power semiconductor element. The system includes a fourth conductor plate connected to the other electrode of the second power semiconductor element via solder, a first metal heat sink disposed opposite the first and third conductor plates via a first insulating member, a second metal heat sink disposed opposite the second and fourth conductor plates via a second insulating member, and a positive and negative terminal for supplying current to the series circuit. The first power semiconductor element, the second power semiconductor element, the first conductor plate, the second conductor plate, the third conductor plate, and the fourth conductor plate are configured such that when the recovery current flows sequentially to the first conductor plate, the first power semiconductor element, the second conductor plate, the third conductor plate, the second power semiconductor element, and the fourth conductor plate, a loop-shaped recovery current path is formed, and eddy currents are induced in the first and second heat sinks by the loop-shaped recovery current.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-43690 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In the invention described in Patent Document 1, there is room for improvement in terms of both cooling and reduction of inductance.

[0010] Solution for solving the problem

[0011] The power conversion device of the first aspect of the present invention includes: a power module that converts direct current (DC) power into alternating current (AC) power; a substrate on which the power module is disposed, including a DC path for transmitting DC power to the power module, having a first surface and a second surface opposite to the first surface, and having a plurality of main flow holes extending from the first surface to the second surface; and a flow path forming body that covers at least a portion of the first surface and the second surface of the substrate in a manner that covers the plurality of main flow holes, forming a flow path for a refrigerant cooling the power module, wherein the plurality of main flow holes are disposed at positions traversing the DC path, and the refrigerant moves from the first surface to the second surface through the main flow holes.

[0012] The effects of the invention are as follows.

[0013] According to the present invention, both cooling and inductance reduction can be achieved. Attached Figure Description

[0014] Figure 1 This is a top view of the power conversion device in the first embodiment.

[0015] Figure 2 From Figure 1 A top view of the power conversion device after removing the flow path formation.

[0016] Figure 3 From Figure 2 A top view of the power conversion device after the molding resin has been removed.

[0017] Figure 4 It is shown Figures 1-3 A cross-sectional view of the power conversion device at section IV-IV.

[0018] Figure 5 This is a circuit diagram of the power conversion device in the first embodiment.

[0019] Figure 6 This is a top view of the power module.

[0020] Figure 7 This is a 3D view of the power module.

[0021] Figure 8 This is the main view of the power module.

[0022] Figure 9 This is a top view of the power conversion device according to the second embodiment.

[0023] Figure 10 It is shown Figure 9 The sectional view of section XX in the image.

[0024] Figure 11This is a top view of the power conversion device in the third embodiment.

[0025] Figure 12 This is a circuit diagram of the power conversion device in the third embodiment. Detailed Implementation

[0026] -First Implementation Method-

[0027] The following is for reference Figures 1 to 8 A first embodiment of the power conversion device will be described.

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, and the technical concept of the present invention can also be realized by combining other known constituent elements. Furthermore, the same symbols are used to label the same elements in each figure, and repeated descriptions are omitted.

[0029] Figure 1 This is a top view of the power conversion device 100. Figure 2 From Figure 1 The image after removing the flow path forming body 25 is shown. Figure 3 From Figure 2 The image shows the result after removing the molding resin 23. The power conversion device 100 is a power conversion device that converts direct current (DC) power obtained from a battery, etc., into alternating current (AC) power supplied to a motor, etc., and constitutes an upper arm circuit and a lower arm circuit of one phase. However, Figure 1 In the middle, the power module is obscured by the molding resin 23 and is therefore not shown.

[0030] like Figure 1 As shown, the power conversion device 100 includes a positive conductor layer 31, a negative conductor layer 32, an AC output terminal conductor 33, a capacitor 40, a control circuit 50 for generating control signals, and a flow path forming body 25. The flow path forming body 25 includes a refrigerant inlet 251 extending towards the front side of the diagram. The positive conductor layer 31, the negative conductor layer 32, and the AC output terminal conductor 33 are contained in any one layer of a substrate 30, which is a flat multilayer substrate. Furthermore, Figures 1-3 In the middle, a shading line is applied to show its correspondence with the sectional view shown later.

[0031] As mentioned above, Figure 2 From Figure 1 The image after removing the flow path forming body 25 is shown. Figure 1 The structure existing inside the flow path forming body 25 is clearly shown. For example... Figure 2 As shown, the substrate 30 also includes a first power module 201 and a second power module 202. The first power module 201 and the second power module 202 each have a heat sink 24. Figure 2 and Figure 3From the perspective of depth, it overlaps with the first power module 201 and the second power module 202.

[0032] The first power module 201 and the second power module 202 are enclosed by molding resin 23, with one side of the heat sink 24 exposed to the outside of the molding resin 23. The molding resin 23 is surrounded by a flow path forming body 25, so the surface of the heat sink 24 is cooled by refrigerant. Furthermore, the first power module 201 and the second power module 202 are electrically insulated from the refrigerant by the molding resin 23. Hereinafter, the first power module 201 and the second power module 202 will be collectively referred to as power module 20.

[0033] like Figure 2 As shown, the substrate 30 has four types of holes. These four types refer to the main flow path hole 301, the secondary flow path hole 302, the DC-side resin-filled hole 304, and the AC-side resin-filled hole 305. Hereinafter, the surface of the substrate 30 closest to the front in the illustration will be referred to as the first surface S1, and the surface closest to the back in the illustration will be referred to as the second surface S2. Furthermore, the DC-side resin-filled hole 304 and the AC-side resin-filled hole 305 will be collectively referred to as the resin-filled hole 303. The main flow path hole 301, the secondary flow path hole 302, and the resin-filled hole 303 are all holes that extend from the first surface S1 to the second surface S2 of the substrate 30. The main flow path hole 301 and the secondary flow path hole 302 have approximately the same shape. The diameter of the resin-filled hole 303 is smaller than the diameters of the main flow path hole 301 and the secondary flow path hole 302.

[0034] The main flow path 301 and the secondary flow path 302 serve as flow paths for refrigerant to move from the first surface S1 to the second surface S2. However, the main flow path 301 also has other functions. The main flow path 301, the secondary flow path 302, and the resin-filled hole 303 all have conductors on their inner walls, thus also serving to connect the layers of the substrate 30, which is a multilayer substrate. The substrate 30 has multiple layers and connects to various electronic devices, therefore eliminating the need for complex-shaped busbars and increasing productivity.

[0035] The first power module 201 is connected to the positive conductor layer 31 having a positive power terminal 311 and the AC output terminal conductor 33 having an AC output terminal 331. The second power module 202 is connected to the negative conductor layer 32 having a negative power terminal 321 and the AC output terminal conductor 33. Thus, electrical energy is supplied from the battery to the first power module 201 and the second power module 202. Furthermore, the first power module 201 and the second power module 202 output AC power from the AC output terminal 331 provided on the AC output terminal conductor 33.

[0036] The substrate 30 is constructed using multiple conductor layers made of materials such as copper and insulating components such as glass epoxy resin. In this embodiment, the substrate 30 has four conductor layers. In the positive conductor layer 31, which has a positive power terminal 311, the lower surface of the substrate 30 and the second inner layer become the main current paths, but near the connection portion connected to the first power module 201 connected to the upper surface of the substrate 30, it is connected to the first power module 201 via a resin-filled hole 303. On the other hand, in the negative conductor layer 32, which has a negative power terminal 321, the upper surface of the substrate 30 and the third inner layer become the main current paths. In this way, through the stacked structure of the positive conductor layer 31 and the negative conductor layer 32, the currents flowing in each conductor are opposed, and the inductance can be reduced by utilizing the magnetic flux cancellation effect.

[0037] The AC output terminal conductor 33 is formed in each layer through resin filling holes 303, and has an AC output terminal 331 for outputting AC power to the motor. As a result, the cross-sectional area of ​​the conductor is increased, which can reduce the inductance.

[0038] The capacitor 40 is composed of a film capacitor or the like. Physically and electrically, the capacitor 40 is mounted between the first power module 201 and the second power module 202 and the positive power terminal 311 and the negative power terminal 321. The capacitor 40 has a positive terminal 401 and a negative terminal 402, which are arranged in parallel with respect to the first power module 201 and the second power module 202. This makes the current path flowing from the capacitor 40 to the first power module 201 and the current path flowing from the second power module 202 to the capacitor 40 more uniform, thereby reducing inductance.

[0039] The control circuit 50 is connected to the first power module 201 and the second power module 202 via control signal wiring 51 such as lead bonding, and is arranged adjacent to each other. This reduces the inductance of the control signal wiring 51, prevents a decrease in component driving performance, and thus prevents increased losses. The control signal wiring 51 is connected to the control circuit 50 via substrate wiring 52 provided in the flow path of the substrate 30.

[0040] The aforementioned main current port 301 is physically located between the first power module 201 and the second power module 202 and the capacitor 40. The aforementioned secondary current port 302 is physically located between the first power module 201 and the second power module 202 and the AC output terminal 331.

[0041] The main channel vias 301 connect all the conductor layers on the substrate 30, and multiple vias are provided in parallel with respect to the first power module 201 and the second power module 202. All the conductors in the four layers of the substrate 30 are composed of either the positive conductor layer 31 or the negative conductor layer 32, and adjacent main channel vias 301 are alternately formed into conductor layers. As a result, the range of current paths flowing in the positive conductor layer 31 and the negative conductor layer 32 is increased, the magnetic flux cancellation effect is enhanced, and thus the inductance can be reduced.

[0042] Figure 4 It is shown Figures 1-3 The diagram shows a cross-sectional view along section IV-IV. The upper part of the diagram shows the first surface S1 of the substrate 30, and the lower part shows the second surface S2 of the substrate 30. Figure 4 The first power module 201, encapsulated in molding resin 23, is shown in the center, with a flow path forming body 25 surrounding the molding resin 23. Therefore, a refrigerant flow path is formed between the molding resin 23 and the flow path forming body 25. Furthermore, Figure 4 In the diagram, for illustration, the refrigerant flow path is represented by a single-dotted line as shown in symbol 259. The refrigerant flows from... Figure 4 The refrigerant flows from the upper right inlet 251 to the lower left outlet 252. The refrigerant flows separately in clockwise and counterclockwise directions.

[0043] Here, the cross-sectional area of ​​the upper flow path in the counterclockwise direction is set as A1, and the cross-sectional area of ​​the upper flow path in the clockwise direction is set as A3. For example, when the flow path is rectangular, the cross-sectional area A1 is calculated as the product of the dimension L1 in the height direction and the dimension in the depth direction. This cross-sectional area A1 is preferably equal to the sum of the cross-sectional areas of the main flow holes 301. For example, when the inner diameter of the main flow holes 301 is set as "r1" and the total number of main flow holes 301 is set as "N1", the following formula 1 is preferably true. Furthermore, N1 is... Figures 2-3 In the example shown, it is "6". If this equation holds, it can prevent the refrigerant from being obstructed in the counterclockwise flow path due to the small area of ​​the main flow path hole 301.

[0044] A1=r1·r1·π×N1…(Equation 1)

[0045] Furthermore, when the inner diameter of the secondary flow path orifice 302 is set to "r2" and the total number of secondary flow path orifices 302 is set to "N2", the following formula 2 is preferably true. Additionally, N2 in... Figures 2-3 In the example shown, it is "6". If this equation holds true, it can prevent the refrigerant from being obstructed in the clockwise flow path due to the smaller area of ​​the secondary flow path orifice 302.

[0046] A3 = r²·r²·π×N²…(Equation 2)

[0047] The first power module 201 and the second power module 202 are inserted into the power module assembly holes 308 located within the substrate 30 and sealed by molding resin 23. Figure 4 As shown, the first power module 201 and the second power module 202 are in contact with the heat sink 24 via solder on their upper and lower surfaces. Since the flow path forming body 25 covers the outer periphery of the molded resin 23 exposed on the surface of the heat sink 24, the surface of the heat sink 24 is in contact with the refrigerant. Therefore, a heat dissipation path is formed from the semiconductor elements of the first power module 201 and the second power module 202 to the heat sink 24 without passing through insulating components, and the heat sink 24 is directly cooled by a refrigerant such as oil. This suppresses the increase in thermal resistance and increases the output of the power conversion device. Furthermore, by providing the main flow path hole 301 and the secondary flow path hole 302 close to the molded resin 23, the refrigerant flow path can be shortened, improving cooling efficiency by reducing pressure loss.

[0048] Figure 5 This is a circuit diagram of the power conversion device 100. As explained so far, capacitor 40 is connected in parallel with the first power module 201 and the second power module 202. The path between capacitor 40 and the first power module 201 is called "P1", and the path between capacitor 40 and the second power module 202 is called "P2". Furthermore, the path between the first power module 201 and the second power module 202 and the AC output terminal 331 is called "P3". P1 and P2 can be called "DC paths" because they carry direct current, and P3 can be called "AC paths" because it carries alternating current.

[0049] The positions of these paths relative to the four types of holes described above are as follows: The columns of positive flow path holes 301 and DC-side resin-filled holes 304 are positioned across DC paths P1 and P2. The columns of secondary flow path holes 302 and AC-side resin-filled holes 305 are positioned across AC path P3.

[0050] In DC paths P1 and P2, for reasons explained below, the inductance is reduced due to the presence of the main flow via 301 and the resin-filled via 303. When the substrate 30 lacks the main flow via 301 and the resin-filled via 303, the current path on the substrate 30 is simply a straight path connecting the terminals, concentrating the current in one path. However, in this embodiment, because the main flow via 301 and the resin-filled via 303 are present on the aforementioned straight path, the current takes a path bypassing these vias. For example, the current takes a path detouring to the right in the forward direction and a path detouring to the left in the forward direction, thus dispersing the current path due to the presence of the main flow via 301 and the resin-filled via 303. This is equivalent to a substantial expansion of the current path, i.e., a reduction in inductance.

[0051] Furthermore, the smaller the diameter of the orifice, the higher the path dispersion effect. Therefore, the resin-filled orifice 303 exhibits a higher path dispersion effect compared to the mainstream orifice 301 for the following reasons: If the diameter of the mainstream orifice 301 is small, the resistance to refrigerant flow increases, thus there is a limit to how much diameter can be reduced. On the other hand, the resin-filled orifice 303 only requires the resin to pass through during the manufacturing process, therefore its diameter can be reduced compared to the mainstream orifice 301.

[0052] Figures 6-8 This is a diagram showing an outline of power module 2. Figure 6 This is a top view of power module 20. Figure 7 This is a 3D view of power module 20. Figure 8 This is the front view of power module 20. Among them, Figure 6 In the text, to make the structure clear, dashed lines are used to indicate the shaded structures.

[0053] The power module 20 constitutes the upper or lower arm circuit of one phase in a power conversion device that converts DC power to AC power. The power module 20 includes an IGBT 10, a diode 11, a collector conductor plate 21, and an emitter conductor plate 22. The plate-shaped IGBT 10 has a main electrode 101 and a control electrode 102 that controls the main current flowing to the main electrode 101. The collector conductor plate 21 and the emitter conductor plate 22 are made of copper. The IGBT 10 and the diode 11 are sandwiched between the collector conductor plate 21 and the emitter conductor plate 22 from both sides, respectively. The IGBT 10 and the diode 11 are connected to the collector conductor plate 21 and the emitter conductor plate 22 via a metal bonding material 12 such as solder.

[0054] According to the first embodiment described above, the following effects can be obtained.

[0055] (1) The power conversion device 100 includes: a power module 20 that converts direct current (DC) power into alternating current (AC) power; a substrate 30 on which the power module 20 is disposed, including a DC path for transmitting DC power to the power module 20, having a first surface S1 and a second surface S2 opposite to the first surface S1, and having a plurality of main flow path holes 301 extending from the first surface S1 to the second surface S2; and a flow path forming body 25 that covers at least a portion of the first surface S1 and the second surface S2 of the substrate in a manner that covers the plurality of main flow path holes 301, forming a flow path for refrigerant to cool the power module 20. The plurality of main flow path holes 301 are disposed at positions traversing the DC path P1 and P2. The refrigerant moves from the first surface S1 to the second surface S2 through the main flow path holes 301. Therefore, the power module 20 can be cooled by the refrigerant, and the DC path is dispersed due to the presence of the main flow path holes 301, thus expanding the range and enhancing the flux cancellation effect, thereby reducing inductance. That is, the power conversion device 100 can achieve both cooling and inductance reduction.

[0056] (2) The power module 20 is cooled by refrigerant flowing along the first surface S1 and refrigerant flowing along the second surface S2. Therefore, the power conversion device 100 can cool the power module 20 from both surfaces.

[0057] (3) The substrate 30 has multiple secondary flow path holes 302 that traverse the AC path P3 through which AC power is transmitted to the power module 20 and extend from the first surface S1 to the second surface S2. Therefore, the refrigerant for cooling the power module 20 can be divided into two paths: one for cooling the upper surface and the other for cooling the lower surface. By shortening the flow path, pressure loss can be reduced. In other words, under the same pressure difference, dividing the path into two increases the flow rate, thereby enhancing the cooling capacity.

[0058] (4) The substrate 30 is constructed by stacking a positive conductor layer 31 for current flowing into the power module 20 and a negative conductor layer 32 for current flowing out of the power module. Therefore, inductance is reduced by canceling magnetic flux.

[0059] (5) In DC paths P1 and P2, capacitors 40 are disposed at positions not covered by the flow path forming body 25. The capacitors 40 are electrically connected in parallel with the power module 20. Therefore, the current path flowing from the capacitor 40 to the first power module 201 and the current path flowing from the second power module 202 to the capacitor 40 can be made uniform, thereby reducing inductance.

[0060] (6) The power module 20 includes a first power module 201 constituting the upper arm and a second power module 202 constituting the lower arm.

[0061] (7) The power module 20 is encapsulated by molding resin 23. A flow path forming body 25 covers the outer periphery of the molding resin 23. The substrate 30 has a plurality of DC-side resin-filled holes 304, which fill the molding resin 23 and extend from the first surface S1 to the second surface S2. The DC-side resin-filled holes 304 are positioned across the DC paths P1 and P2. Therefore, the DC-side resin-filled holes 304 also have the effect of dispersing the DC path, thereby reducing inductance.

[0062] (8) The diameter of the resin-filled hole 303 is smaller than the diameter of the main path hole 301. Therefore, the DC path can be more dispersed, and the inductance can be further reduced.

[0063] (Modified Example)

[0064] The power conversion device 100 may also have only one power module. The power conversion device 100 may also omit at least one of the DC-side resin filling hole 304 and the AC-side resin filling hole 305. The power module 20 may also have a heat sink 24 on only one side. That is, it may be configured to cool the power module 20 only from the first side S1 and the second side S2 of the substrate 30. The shapes of the main flow path hole 301 and the secondary flow path hole 302 may also be different; for example, their diameters may also be different.

[0065] -Second Implementation Method-

[0066] Reference Figures 9-10 A second embodiment of the power conversion device will be described. In the following description, the same symbols are used for components identical to those in the first embodiment, and the main differences will be explained. Points not specifically described are the same as in the first embodiment. The main difference between this embodiment and the first embodiment is the absence of a secondary flow path orifice.

[0067] Figure 9 This is a top view of the power conversion device 100A according to the second embodiment. Among them, Figure 9 The flow path forming body 25 is removed from the diagram. That is, Figure 9 Equivalent to the first embodiment Figure 2 . Figure 9 The power conversion device 100A shown does not have Figure 2 The difference between this and the power conversion device 100 of the first embodiment lies in the presence of the secondary flow path orifice 302. Furthermore, although in Figure 9 The refrigerant outlet 252 is located behind the substrate 30 from a certain perspective and is not shown, but its position differs from that in the first embodiment. Refer to the following... Figure 10 Explain the differences in actions caused by differences in structure.

[0068] Figure 10 It is shown Figure 9 The sectional view of section XX in the image. Figure 10 Equivalent to the first embodiment Figure 4 In the first embodiment, Figure 4 The refrigerant outlet 252 in the lower left of the diagram is present. Figure 10 The device moves to the lower right of the diagram. As described above, the power conversion device 100A of the second embodiment does not have the secondary flow path 302, therefore... Figure 10 Only a counter-clockwise flow path exists. In the first embodiment, the heat sink 24 at the bottom of the figure is cooled by refrigerant flowing in a clockwise flow path, but in this embodiment, all heat sinks 24 are cooled by refrigerant flowing in a counter-clockwise flow path.

[0069] According to the second embodiment described above, compared with the first embodiment, it is not necessary to form the secondary flow path hole 302 during the processing of the substrate 30, thus reducing the processing time and increasing the productivity.

[0070] -Third Implementation Method-

[0071] Reference Figures 11-12 A third embodiment of the power conversion device will be described. In the following description, the same symbols are used for components identical to those in the first embodiment, and the main differences will be explained. Points not specifically described are the same as in the first embodiment. The main difference in this embodiment compared to the first embodiment is the inclusion of multiple capacitors.

[0072] Figure 11 This is a top view of the power conversion device 100B in the third embodiment. Figure 11 Equivalent to the first embodiment Figure 1 The power conversion device 100B is equipped with multiple ceramic capacitors and other capacitors 40 with narrowly spaced terminals. These capacitors 40 are connected in parallel with respect to the first power module 201 and the second power module 202.

[0073] Figure 12 This is the circuit diagram of the power conversion device 100B. (For example...) Figure 12 As shown, the power conversion device 100B includes a plurality of capacitors 40 connected in parallel.

[0074] According to the third embodiment described above, in addition to the effects of the first embodiment, the following effects can also be obtained.

[0075] (9) In the DC paths P1 and P2 of the power conversion device 100B, multiple capacitors 40 are arranged in positions not covered by the flow path forming body 25. The multiple capacitors 40 are electrically connected in parallel with the power module 20. Therefore, multiple current paths can be ensured, the magnetic flux cancellation effect between the positive conductor layer 31 and the negative conductor layer 32 is enhanced, and the inductance can be reduced.

[0076] In the above-described embodiments and variations, the structure of the functional blocks is merely one example. Several functional structures shown as different functional blocks can be integrated into one unit, or the structure represented by a single functional block diagram can be divided into two or more functions. Furthermore, it is also possible for a portion of the functions possessed by each functional block to be possessed by other functional blocks.

[0077] The various embodiments and modifications described above can also be combined. Various embodiments and modifications have been described above, but the present invention is not limited to the above content. Other methods considered within the scope of the technical concept of the present invention are also included within the scope of the present invention.

[0078] The disclosures of the following priority-based applications are incorporated herein by reference.

[0079] Japanese Patent Application 2020-51009 (filed on March 23, 2020)

[0080] Explanation of symbols

[0081] 100, 100A, 100B—Power conversion device; 20—Power module; 201—First power module; 202—Second power module; 23—Molded resin; 25—Flow path forming body; 30—Substrate; 31—Positive conductor layer; 32—Negative conductor layer; 33—AC output terminal conductor; 301—Positive flow path hole; 302—Secondary flow path hole; 303—Resin filling hole; 304—DC side resin filling hole; 305—AC side resin filling hole; 40—Capacitor; 50—Control circuit; 51—Control signal wiring; 52—Inner substrate wiring within the flow path.

Claims

1. A power conversion device, characterized in that, have: A power module that converts DC power into AC power; The substrate, which is configured with the power module, includes a DC path for transmitting DC power to the power module, has a first surface and a second surface facing the first surface, and has a plurality of main channel holes extending from the first surface to the second surface. as well as A flow path forming body covers at least a portion of the first and second surfaces of the substrate in a manner that covers the plurality of main flow path holes, thereby forming a flow path for cooling the refrigerant of the power module. The aforementioned main channel holes are located at positions that traverse the aforementioned DC path. The refrigerant moves from the first surface to the second surface through the main flow channel. The substrate also has a plurality of secondary flow path holes that traverse the AC path through which AC power is transmitted to the power module and extend from the first surface to the second surface.

2. The power conversion device according to claim 1, characterized in that, The power module is cooled by the refrigerant flowing along the first surface and the refrigerant flowing along the second surface.

3. The power conversion device according to claim 1, characterized in that, The substrate is constructed by stacking a positive conductor layer into which the current flowing into the power module flows and a negative conductor layer into which the current flowing out of the power module flows.

4. The power conversion device according to claim 1, characterized in that, In the aforementioned DC path, capacitors are placed at locations not covered by the aforementioned flow path forming body. The aforementioned capacitor is electrically connected in parallel with the aforementioned power module.

5. The power conversion device according to claim 1, characterized in that, The aforementioned power module is configured to include a first power module constituting the upper arm and a second power module constituting the lower arm.

6. The power conversion device according to claim 1, characterized in that, The aforementioned power module is encapsulated in resin. The aforementioned flow path forming body covers the outer periphery of the aforementioned resin. The substrate also has a plurality of resin-filled holes, which are filled with resin and extend from the first surface to the second surface. The aforementioned resin-filled holes are positioned at locations that traverse the aforementioned DC path.

7. The power conversion device according to claim 6, characterized in that, The diameter of the resin-filled hole is smaller than the diameter of the main channel hole.

8. The power conversion device according to claim 1, characterized in that, In the aforementioned DC path, multiple capacitors are disposed at locations not covered by the aforementioned flow path forming body. The aforementioned capacitors are connected in parallel to the aforementioned power module.

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