Power conversion device

Abstract

A power conversion device according to the present application includes a substrate; a plurality of first semiconductor elements arranged in a second direction on one side of the substrate in a first direction; a plurality of second semiconductor elements arranged in the second direction on the other side of the substrate in the first direction; and a flow path forming member having a wall opposed to the other face of the substrate with a space therebetween, the wall having a slit extending in the second direction between the first semiconductor elements and the second semiconductor elements, and a through hole penetrating the wall on a side closer to the second direction than the slit, the slit and the through hole being separated by a separation portion in the flow path in a state in which a gap on the one side in the first direction and a gap on the other side in the first direction are provided, one of the slit and the through hole being a supply port for refrigerant, and the other of the slit and the through hole being a discharge port for refrigerant.

Description

Technical Field

[0001] This application relates to power conversion devices. Background Technology

[0002] Multiple power conversion devices are installed in electric vehicles, such as electric cars or hybrid vehicles, which use electric motors as a drive source. A power conversion device is a device that converts input current from direct current (DC) to alternating current (AC), from AC to DC, or converts input voltage to a different voltage. Specifically, power conversion devices include: chargers used to convert commercial AC power to DC power and charge high-voltage batteries; DC / DC converters used to convert the DC power from high-voltage batteries to the voltage of batteries used in auxiliary equipment (e.g., 12V); and inverters, etc., used to convert DC power from batteries to AC power for the electric motor.

[0003] Power conversion devices used in electric or hybrid vehicles require miniaturization and high output. With the increasing output of power conversion devices, multiple semiconductor elements and capacitors housed within them handle large currents, leading to increased heat generation from these elements and capacitors. Therefore, power conversion devices are equipped with cooling structures that use refrigerant to cool these semiconductor elements and capacitors.

[0004] When using refrigerant to cool multiple heat-generating semiconductor elements, it is preferable to prevent any particular semiconductor element from reaching a high temperature and to reduce the temperature deviation among the multiple semiconductor elements. However, when a cooling channel for refrigerant to flow along the long side is arranged directly below multiple semiconductor elements arranged along their long side, the refrigerant intended for cooling one semiconductor element is used to cool another, resulting in the semiconductor element being adequately cooled first while the one cooled later is not. Therefore, there is a problem of excessive temperature deviation among the multiple semiconductor elements. A structure to avoid this problem has been disclosed (for example, see Patent Document 1). In the disclosed structure, by providing a component called a separator together with the cooling housing, the refrigerant is divided midway through the flow path, and multiple semiconductor elements are cooled separately using refrigerant at a uniform temperature.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2016 / 117094 Summary of the Invention

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

[0009] In Patent Document 1 mentioned above, since the refrigerant is divided midway through the flow path using a separator, multiple semiconductor elements can be cooled separately using refrigerant at a uniform temperature. However, since a separator requiring airtightness is installed in a part of the flow path, there is an increase in the number of components and installation time. The increase in the number of components and installation time may lead to an increase in the weight and cost of the power conversion device. Furthermore, in order to ensure the airtightness of the flow paths on the upstream and downstream sides inside the cooling housing and to install the separator, from the viewpoint of miniaturizing and lightweighting the power conversion device, there is a problem that the space inside the cooling housing is usually insufficient, making it difficult to seal the refrigerant at the inlet and outlet surfaces that meet the flow inlet and outlet surfaces inside the cooling housing of the separator.

[0010] Therefore, the purpose of this application is to obtain a power conversion device that uses a refrigerant of uniform temperature to cool multiple semiconductor elements separately, while being easy to manufacture and improving production efficiency without increasing the number of components.

[0011] Technical means for solving technical problems

[0012] The power conversion device disclosed in this application includes: a substrate formed in the shape of a plate; a plurality of first semiconductor elements arranged along the second direction on one side of the first direction on one side of the substrate when a specific direction parallel to one surface of the substrate is designated as a first direction and a direction orthogonal to the first direction parallel to one surface of the substrate is designated as a second direction; a plurality of second semiconductor elements arranged along the second direction on the other side of the first direction on one surface of the substrate; and a flow path forming member having a wall spaced apart from the other surface of the substrate and forming a refrigerant flow path for refrigerant to flow in the space, wherein the flow path is perpendicular to one surface of the substrate. When viewed from above, the wall has one or more slits extending through the wall and extending in a second direction between a plurality of first semiconductor elements and a plurality of second semiconductor elements; and a through hole in the wall on a portion of the wall further in the second direction than the slits. The wall also has a partition in the refrigerant flow path, which, with a gap on one side of the first direction and a gap on the other side of the first direction, extends in the first direction and separates the slits and the through hole. One of the slits and the through hole is a supply port for supplying refrigerant to the refrigerant flow path, and the other is a discharge port for discharging refrigerant from the refrigerant flow path.

[0013] Invention Effects

[0014] According to the power conversion device disclosed in this application, the flow path forming member has a wall with a slit and a through hole penetrating the wall. In the refrigerant flow path, which is the space between the wall and a substrate on which multiple semiconductor elements and multiple second semiconductor elements are disposed, a partition is provided to separate the slit and the through hole. One of the slit and the through hole is a supply port for supplying refrigerant to the refrigerant flow path, and the other is a discharge port for discharging refrigerant from the refrigerant flow path. Therefore, the refrigerant flowing into the refrigerant flow path is divided, preventing refrigerant already used in the cooling of a primary semiconductor element from passing through to the side of other semiconductor elements. Thus, refrigerant with a uniform temperature can be used to cool multiple first semiconductor elements and multiple second semiconductor elements separately. Furthermore, since the slit and the through hole are formed on the flow path forming member, and the partition is provided within the refrigerant flow path, a power conversion device that is easy to manufacture and has improved production efficiency without increasing the number of components can be obtained. Attached Figure Description

[0015] Figure 1 This is a top view of the power conversion device according to Embodiment 1.

[0016] Figure 2 This is a top view of the power conversion device according to Embodiment 1.

[0017] Figure 3 Is Figure 1 A cross-sectional view of the power conversion device cut off at section AA.

[0018] Figure 4 Is Figure 1 A cross-sectional view of the power conversion device cut off at the BB section location.

[0019] Figure 5 This is a top view of other power conversion devices involved in Embodiment 1.

[0020] Figure 6 This is a perspective view of the main parts of the power conversion device involved in Embodiment 1.

[0021] Figure 7 This is a cross-sectional view illustrating the power conversion device of the comparative example.

[0022] Figure 8 This is a top view of the power conversion device according to Embodiment 2.

[0023] Figure 9 This is a top view of other power conversion devices involved in Embodiment 2.

[0024] Figure 10 This is a top view of the power conversion device according to Embodiment 3.

[0025] Figure 11 Is Figure 10 A cross-sectional view of the power conversion device cut off at the CC section position.

[0026] Figure 12 This is a bottom view of the power conversion device according to Embodiment 3.

[0027] Figure 13 This is a bottom view of another power conversion device involved in Embodiment 3. Detailed Implementation

[0028] 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.

[0029] Implementation method 1.

[0030] Figure 1 This is a top view of the power conversion device 100 according to Embodiment 1. Figure 2 This is a top view of the power conversion device 100, from... Figure 1 The diagram shows the result after removing substrate 2 and semiconductor module 3. Figure 3 Is Figure 1 A cross-sectional view of the power conversion device 100 cut off at section AA. Figure 4 Is Figure 1 A cross-sectional view of the power conversion device 100 cut off at the BB section position. Figure 5 This is a top view of other power conversion devices involved in Embodiment 1, from... Figure 1 The diagram shows the result after removing substrate 2 and semiconductor module 3. Figure 6 This is a perspective view of the main part of the power conversion device 100, namely the refrigerant flow path 11. The power converter 100 is a device with a switching circuit for controlling power, converting input current from DC to AC, from AC to DC, or converting input voltage to different voltages.

[0031] <Power Conversion Device 100>

[0032] The power conversion device 100 includes a substrate 2 formed in a plate shape, a plurality of first semiconductor elements 14, a plurality of second semiconductor elements 15, and a flow path forming member 1a. A specific direction parallel to one surface of the substrate 2 is designated as a first direction, and a direction orthogonal to the first direction parallel to one surface of the substrate 2 is designated as a second direction. Figure 1In the diagram, the first direction is indicated by arrow A, and the second direction is indicated by arrow B. The substrate 2 is formed, for example, in a rectangular plate shape, and the sides of one face of the substrate 2 are arranged parallel to either the first or second direction. When the substrate 2 is formed in a rectangular plate shape, the first semiconductor element 14 and the second semiconductor element 15 can be effectively arranged on one face of the substrate 2, thereby enabling miniaturization of the power conversion device 100. The substrate 2 is formed of a metal with high thermal conductivity, such as aluminum.

[0033] exist Figure 1 In the diagram, the outlines of the first semiconductor element 14 and the second semiconductor element 15 are shown in dashed lines. A plurality of first semiconductor elements 14 are arranged along a second direction on one side of a surface of the substrate 2 in a first direction. A plurality of second semiconductor elements 15 are arranged along a second direction on the other side of a surface of the substrate 2 in the same direction. In this embodiment, the first semiconductor elements 14 are disposed on one side of the first direction, and the second semiconductor elements 15 are disposed on the other side of the first direction; however, it is also possible to dispose of the first semiconductor elements 14 on the other side of the first direction and the second semiconductor elements 15 on one side of the first direction.

[0034] The power conversion device 100 includes a plurality of semiconductor modules 3, each semiconductor module 3 being formed from one or more first semiconductor elements 14 and one or more second semiconductor elements 15. The plurality of semiconductor modules 3 are thermally connected to one side of a substrate 2 and arranged along a second direction. In this embodiment, a semiconductor module 3 is formed from the first semiconductor elements 14, i.e., semiconductor elements 13a and 13b, and the second semiconductor elements 15, i.e., semiconductor elements 13c and 13d, and the power conversion device 100 includes three semiconductor modules 3. The number of semiconductor elements in the semiconductor module 3 is not limited to this, nor is the number of semiconductor modules 3 included in the power conversion device 100 limited to this. Furthermore, in this embodiment, the semiconductor modules 3 are formed in a cuboid shape and arranged along the same direction. By arranging the semiconductor modules 3 in the same direction, the power conversion device 100 can be miniaturized.

[0035] use Figure 4An example of the internal structure of semiconductor module 3 will be described. Semiconductor elements 13a and 13b are electrically connected to one side of conductive member 21 via solder 22. Semiconductor element 13a is, for example, an IGBT (Insulated Gate Bipolar Transistor), and semiconductor element 13b is, for example, a diode. Conductive member 21 is a metal plate with good electrical and thermal conductivity, for example, made of copper. The other side of conductive member 21 is thermally connected to one side of substrate 2 via insulating material 20. Insulating material 20 is, for example, an insulating ceramic resin material. Semiconductor elements 13a, 13b, 13c, 13d, conductive member 21, and insulating material 20 are sealed by sealing member 23. The side of insulating material 20 opposite to the side connected to conductive member 21 is exposed from sealing member 23. Sealing member 23 is, for example, a molding resin.

[0036] In this embodiment, an example of the power conversion device 100 constituting a three-phase AC inverter will be described. The structure of the power conversion device 100 is not limited to a three-phase AC inverter, but may also be a power conversion device with a built-in dual three-phase inverter or DC-DC converter. The refrigerant flow path 11 described later is applicable to power conversion devices having multiple semiconductor elements, and is therefore not a limitation of its application. When the power conversion device 100 is a three-phase AC inverter, the first semiconductor element 14 is the element forming the upper arm, and the second semiconductor element 15 is the element forming the lower arm. The power conversion device 100 converts the supplied DC power into AC power and provides the converted three-phase (U-phase, V-phase, W-phase) AC power to the load. Each layer of U-phase, V-phase, and W-phase is composed of two arms, an upper arm and a lower arm. Any one of the three semiconductor modules 3 corresponds to U-phase, V-phase, and W-phase. The semiconductor elements 13a and 13b are not limited to IGBTs and diodes, but may also be field-effect transistors (MOSFETs).

[0037] like Figure 3As shown, the flow path forming member 1a has a wall 5 that is spaced apart from the other side of the substrate 2. A refrigerant flow path 11 is formed in the spaced-apart portion for refrigerant flow. For example, water or ethylene glycol solution is used as the refrigerant. By allowing the refrigerant to flow through the refrigerant flow path 11, the first semiconductor element 14 and the second semiconductor element 15 in the semiconductor module 3 are cooled, thereby suppressing the heating of the first semiconductor element 14 and the second semiconductor element 15. The housing 1 is formed by the flow path forming member 1a and a sidewall 1b disposed around the flow path forming member 1a. The housing 1 houses the substrate 2, a plurality of first semiconductor elements 14, and a plurality of second semiconductor elements 15. The flow path forming member 1a and the sidewall 1b are made of, for example, aluminum. A structure for sealing the refrigerant in the refrigerant path 11 is, for example, a structure in which an O-ring is provided between the flow path forming member 1a and the substrate 2, and the seal is achieved by the elastic deformation of the O-ring. Alternatively, friction stir welding (FSW) can be used to weld the flow path forming member 1a to the substrate 2 and seal it. These sealing structures are not illustrated as they are common cooling structures that use refrigerants.

[0038] The power conversion device 100 includes a first cooling fin 4a and a second cooling fin 4b. Viewed from a direction perpendicular to the other side of the substrate 2, the first cooling fin 4a is disposed on a portion of the other side of the substrate 2 that overlaps with at least a plurality of first semiconductor elements 14. Viewed from a direction perpendicular to the other side of the substrate 2, the second cooling fin 4b is disposed on a portion of the other side of the substrate 2 that overlaps with at least a plurality of second semiconductor elements 15. The first cooling fin 4a and the second cooling fin 4b are, for example, prismatic fins integrally formed with the substrate 2. The first cooling fin 4a and the second cooling fin 4b are not limited to prismatic fins; they can also be needle-shaped fins or parallel fins, and the fin shape is not specified in this application. By providing the first cooling fin 4a and the second cooling fin 4b, the heat dissipation of the first semiconductor elements 14 and the second semiconductor elements 15 can be improved.

[0039] <Comparative Example>

[0040] Before describing the refrigerant flow path 11, the refrigerant flow path 110 of the comparative example will be described. Figure 7 This is a cross-sectional view illustrating the power conversion device 200 of the comparative example, in comparison with... Figure 3 The diagram is obtained by cutting off the power conversion device 200 at the same location. Figure 7 In the diagram, the refrigerant flows from left to right in the direction of the arrow within the refrigerant flow path 110. The refrigerant first cools the first semiconductor element 14, and then cools the second semiconductor element 15. Because the second semiconductor element 15 is cooled by the refrigerant whose temperature has risen after cooling the first semiconductor element 14, the cooling of the second semiconductor element 15 is insufficient. Therefore, in the structure shown in the comparative example, the temperature of the second semiconductor element 15 is higher than that of the first semiconductor element 14.

[0041] <Refrigerant Flow Path 11>

[0042] The main part of this application, namely the refrigerant flow path 11, will be described. For example... Figure 2 As shown, wall 5 has a slit 12 and a through hole 8. (As indicated...) Figure 1 As shown, viewed from a direction perpendicular to each surface of the substrate 2, the slit 12 is disposed between a plurality of first semiconductor elements 14 and a plurality of second semiconductor elements 15. The slit 12 penetrates the wall 5, extends in a second direction, and is divided into one or more sections. In this embodiment, as... Figure 2 As shown, slits 12a, 12b, and 12c are provided, which are divided into three sections, but a single slit without division is also possible. The through-hole 8 is configured to penetrate the wall 5 in a portion closer to the second direction than the slit 12 in the wall 5. A partition 9 is provided on the refrigerant flow path 11. The partition 9 extends in the first direction, separating the slit 12 and the through-hole 8, with gaps on one side of the first direction and gaps on the other side of the first direction. The partition 9 is integrated with one of the substrate 2 and the flow path forming member 1a. Since the partition 9 is located inside the refrigerant flow path 11, airtightness is not required at the location where the partition 9 is located. One of the slit 12 and the through-hole 8 is a refrigerant supply port to the refrigerant flow path 11, and the other is a refrigerant discharge port from the refrigerant flow path 11.

[0043] The refrigerant flow path 11 is provided with one or more slit partitions 6. The slit partitions 6 are provided at one or more locations in the region where the slits 12 are located in a second direction. With a gap on one side of the first direction and a gap on the other side of the first direction provided, the slit partition 6 extends in the first direction, separating one side and the other side of the second direction. The slit partition 6 is integrated with one of the substrate 2 and the flow path forming member 1a. In this embodiment, two slit partitions 6a and 6b are provided on the refrigerant flow path 11, but the number of slit partitions 6 is not limited to this, and the power conversion device 100 may also be configured without slit partitions 6.

[0044] First of all, Figure 2 , Figure 3 and Figure 6 The flow of refrigerant in the refrigerant flow path 11 is explained when the slit 12 is the supply port and the through hole 8 is the discharge port. Figure 2 , Figure 3 and Figure 6 The arrows indicate the direction of refrigerant flow. When refrigerant flows into refrigerant flow path 11 from slit 12, after the refrigerant flows into refrigerant flow path 11 from slit 12, as... Figure 3As shown, the refrigerant is divided into a first refrigerant flowing through the first cooling fin 4a side and a second refrigerant flowing through the second cooling fin 4b side. Figure 2 As shown, the first refrigerant is discharged from the through hole 8 through a gap on one side of the end of the partition 9 in a first direction. The second refrigerant is discharged from the through hole 8 through a gap on the other side of the end of the partition 9 in the first direction. Figure 3 As shown, by allowing the first refrigerant to flow through the first cooling fin 4a side, a plurality of first semiconductor elements 14 are cooled. By allowing the second refrigerant to flow through the second cooling fin 4b side, a plurality of second semiconductor elements 15 are cooled. In this embodiment, the first and second refrigerants are discharged from one through-hole 8, but this is not a limitation. Two through-holes 8 may also be provided, from which the first and second refrigerants are discharged respectively.

[0045] The partition 9 prevents the first refrigerant from flowing back to the second cooling fin 4b side and the second refrigerant from flowing back to the first cooling fin 4a side. The first refrigerant used to cool the plurality of first semiconductor elements 14 is not used to cool the plurality of second semiconductor elements 15, and the second refrigerant used to cool the plurality of second semiconductor elements 15 is not used to cool the plurality of first semiconductor elements 14. With this structure, since the refrigerant flowing into the refrigerant flow path 11 can be divided to prevent refrigerant used in one cooling of a semiconductor element from passing through the side of another semiconductor element, it is possible to use refrigerants with uniform temperature to cool the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 separately. The slit 12 and the through hole 8 are formed on the flow path forming member 1a, and the partition 9 is disposed in the refrigerant flow path 11. The partition 9 is integrally formed with the substrate 2 or the flow path forming member 1a, so a power conversion device 100 that is easy to manufacture and has improved production efficiency can be obtained without increasing the number of parts.

[0046] In the structure of this embodiment, which has two slit partitions 6a and 6b, as follows: Figure 6As shown, the area of ​​the refrigerant flow path 11 with slit 12 is divided into three parts. The first refrigerant flowing into the refrigerant flow path 11 from slit 12a passes through the gap on one side of the end of the slit divider 6a in the first direction, and faces the through hole 8. The first refrigerant flowing into the refrigerant flow path 11 from slit 12b passes through the gap on one side of the end of the slit divider 6b in the first direction, and faces the through hole 8. The first refrigerant flowing into the refrigerant flow path 11 from slit 12c passes through the gap on one side of the end of the divider 9 in the first direction, and faces the through hole 8. The second refrigerant flowing into the refrigerant flow path 11 from slit 12a passes through the gap on the other side of the end of the slit divider 6a in the first direction, and faces the through hole 8. The second refrigerant flowing into the refrigerant flow path 11 from slit 12b passes through the gap on the other side of the end of the slit divider 6b in the first direction, and faces the through hole 8. The second refrigerant flowing into the refrigerant flow path 11 from slit 12c passes through the gap on the other side of the end of the divider 9 in the first direction, and faces the through hole 8. By providing the slit divider 6, the refrigerant can be further divided, and refrigerant already used in one cooling operation can be further prevented from passing through the other cooling fin side. Therefore, refrigerant with a more uniform temperature can be used to cool multiple first semiconductor elements 14 and multiple second semiconductor elements 15 separately. The slit divider 6 is provided in the refrigerant flow path 11 and is integrally formed with the substrate 2 or the flow path forming member 1a. Therefore, a power conversion device that is easy to manufacture and has improved production efficiency can be obtained without increasing the number of parts.

[0047] In this embodiment, such as Figure 4 As shown, when viewed from a direction perpendicular to one side of the substrate 2, the slit partitions 6a and 6b are disposed between the plurality of semiconductor modules 3. With this structure, since the refrigerant does not flow through the parts where the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 are not disposed, the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 can be effectively cooled.

[0048] In this embodiment, such as Figure 2 As shown, a slit partition 6 is provided at the dividing portion of the slit 12. With this structure, the slit partition 6 can be easily integrated with the flow path forming member 1a. Furthermore, the slit partition 6 can be integrated with the flow path forming member 1a with high strength.

[0049] In this embodiment, such as Figure 1As shown, multiple first semiconductor elements 14 and multiple second semiconductor elements 15 are arranged in a row. With this structure, since the refrigerant flowing directly beneath a semiconductor element to cool that element does not flow directly beneath other semiconductor elements to cool them, refrigerants with uniform temperatures can be used to cool the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 separately. Furthermore, where space constraints make it difficult to arrange the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 in separate rows, it is desirable that at least the number of each type of semiconductor element is equal. With the same number, the heat generated by each of the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 can be made equal.

[0050] In this embodiment, the number of first semiconductor elements 14 and the number of second semiconductor elements 15 are equal. With this structure, the difference in the degree of heat generation between the multiple first semiconductor elements 14 and the multiple second semiconductor elements 15 is reduced, thus allowing for efficient cooling of the multiple first semiconductor elements 14 and the multiple second semiconductor elements 15 using a refrigerant with a uniform temperature. Furthermore, if the degree of heat generation of the multiple first semiconductor elements 14 and the multiple second semiconductor elements 15 is the same, then since the multiple first semiconductor elements 14 and the multiple second semiconductor elements 15 can be cooled uniformly, the heat generation of each of the multiple first semiconductor elements 14 and the multiple second semiconductor elements 15 can be made equal.

[0051] pass Figure 5 The flow of refrigerant in the refrigerant flow path 11 is explained when the through hole 8 is the supply port and the slit 12 is the discharge port. Figure 5 The arrows indicate the direction of refrigerant flow. When refrigerant flows into the refrigerant flow path 11 from the through-hole 8, after flowing into the refrigerant flow path 11, it is divided into a third refrigerant passing through the gap on one side of the end of the partition 9 in the first direction and a fourth refrigerant passing through the other side of the end of the partition 9 in the first direction. The third refrigerant flows through the refrigerant flow path 11 on the side of the first cooling fin 4a and is discharged from the slit 12. The fourth refrigerant flows through the refrigerant flow path 11 on the side of the second cooling fin 4b and is discharged from the slit 12. By allowing the third refrigerant to flow through the side of the first cooling fin 4a, a plurality of first semiconductor elements 14 are cooled. By allowing the fourth refrigerant to flow through the side of the second cooling fin 4b, a plurality of second semiconductor elements 15 are cooled.

[0052] Even if the through hole 8 is set as the supply port and the slit 12 is set as the discharge port, the same effect can be obtained as when the through hole 8 is set as the discharge port and the slit 12 is set as the supply port. Depending on the structure and configuration of the components connected to the refrigerant flow path 11 outside the housing 1, it is possible to select which of the slit 12 and the through hole 8 is used as the supply port or the discharge port.

[0053] The housing 1 is manufactured, for example, by casting. By casting the housing 1 with the portion forming the slit 12 in a mold, the slit 12 can be formed at low cost without additional manufacturing steps. Furthermore, since the slit 12 is integrated with the housing 1, the position of the slit 12 will not shift during the manufacturing process of the housing 1. For example, if the power conversion device 100 is a power conversion device for a hybrid electric vehicle, the housing 1 is typically a thick metal housing, thus the housing 1 has high strength, and the slit 12 cannot be deformed. Moreover, for the portion forming the refrigerant flow path for the cooling fins, high strength is required due to the high refrigerant pressure. By forming the refrigerant flow path in the high-strength housing 1 as described above, it is not necessary to reinforce the portion forming the cooling fins for the refrigerant flow path, thereby reducing the cost of the power conversion device 100.

[0054] By using a split refrigerant, namely a first refrigerant and a second refrigerant, or a third refrigerant and a fourth refrigerant, to consistently supply refrigerant at the same temperature to one side of the plurality of first semiconductor elements 14 and one side of the plurality of second semiconductor elements 15, the temperature deviation between the first semiconductor elements 14 and the second semiconductor elements 15 can be reduced. In a power conversion device where the upper and lower arms drive an inverter, since the upper and lower arms typically use the same semiconductor elements, the heat generation of each arm is approximately equal. Therefore, by consistently supplying refrigerant at the same temperature to both the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15, the temperature deviation between the upper and lower arms can be reduced.

[0055] In this embodiment, the first semiconductor element 14 forms the upper arm, and the second semiconductor element 15 forms the lower arm, but is not limited thereto. If the semiconductor elements are uniformly arranged in each portion of the segmented refrigerant flow, then each uniformly arranged semiconductor element will be uniformly cooled. Therefore, it is also possible to configure the first semiconductor element 14 to form the lower arm and the second semiconductor element 15 to form the upper arm. Furthermore, it is also possible to have a configuration in which the semiconductor elements forming the upper arm and the semiconductor elements forming the lower arm are mixed in each portion of the segmented refrigerant flow. For example, it is also possible to make the semiconductor elements forming the upper arm and the semiconductor elements forming the lower arm appear to be mixed in each portion of the segmented refrigerant flow. Figure 1 The configuration of semiconductor elements in semiconductor module 3 after rotating 90 degrees.

[0056] In this embodiment, examples of the first semiconductor element 14 and the second semiconductor element 15 are IGBTs, diodes, or MOSFETs, but are not limited to these. Any other element can be used as long as the first semiconductor element 14 and the second semiconductor element 15 are elements that generate heat due to the passage of current. Furthermore, it is desirable that the number of elements constituting the plurality of first semiconductor elements 14 is the same as the number of elements constituting the plurality of second semiconductor elements 15, but the number is not particularly limited.

[0057] In the case where the power conversion device 100 is for a hybrid electric vehicle, the power conversion device 100 includes a protection system that individually monitors the temperature of multiple semiconductor elements and limits the output of the power conversion device when the temperature of any one semiconductor element exceeds a predetermined temperature. For example, an on-chip temperature sensor using diodes is employed in the temperature measurement of the semiconductor elements. Figure 7 In the comparative example shown, when the temperature of the insufficiently cooled second semiconductor element 15 rises, the protection system activates to protect the second semiconductor element 15, even though the temperature of the first semiconductor element 14 has a margin of safety. If the protection system activates, the output of the power conversion device cannot function optimally. In this case, the load switching from electric motor drive to engine drive occurs prematurely, hindering improvements in fuel economy and negatively impacting acceleration and ride comfort.

[0058] The power conversion device 100 shown in Embodiment 1 is particularly suitable for this type of hybrid vehicle. As with the power conversion device 100 of Embodiment 1, if the temperature deviation of multiple semiconductor elements is reduced, it is not necessary to determine the size of the semiconductor element to match the downstream side where the refrigerant temperature is higher. Since the size of the semiconductor element is not determined based on the downstream side where the refrigerant temperature is higher, the size of the semiconductor element can be reduced. Furthermore, in the prior example, a separator is added to the refrigerant flow path, but since the slit 12 and the through hole 8 are formed on the flow path forming member 1a, and the partition 9 is integrally formed with the substrate 2 or the flow path forming member 1a, in conjunction with… Figure 7 In the comparative example shown, compared to the case without increasing the number of components, the refrigerant is divided, enabling the use of refrigerant at a uniform temperature to cool multiple semiconductor elements separately. Furthermore, since the cooling efficiency of each individual semiconductor element is improved, the spray capacity required by the cooling pump supplying the refrigerant can be reduced. Because the spray capacity of the cooling pump can be reduced without increasing the number of components, the cost of the power conversion device 100 is reduced, thereby enabling the vehicle equipped with the power conversion device 100 to achieve weight reduction and improved fuel economy.

[0059] As described above, in the power conversion device 100 of Embodiment 1, the flow path forming member 1a has a wall 5 with a slit 12 penetrating the wall 5 and a through hole 8 penetrating the wall 5. In the space between the wall 5 and the substrate 2 on which a plurality of first semiconductor elements 14 and a plurality of second semiconductor elements 15 are disposed, i.e., the refrigerant flow path 11, there is a partition 9 separating the slit 12 and the through hole 8. One of the slit 12 and the through hole 8 is a supply port for supplying refrigerant to the refrigerant flow path 11, and the other of the slit 12 and the through hole 8 is a discharge port for discharging refrigerant from the refrigerant flow path 11. The refrigerant flowing into the refrigerant flow path 11 is divided, thereby preventing the refrigerant used in the first cooling of the semiconductor elements from passing through the side of other semiconductor elements. Therefore, it is possible to use refrigerants with uniform temperature to cool the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 respectively. Furthermore, the slit 12 and the through hole 8 are formed on the flow path forming member 1a, and the partition 9 is disposed in the refrigerant flow path 11 and is integrally formed with the substrate 2 or the flow path forming member 1a. Therefore, a power conversion device 100 that is easy to manufacture and has improved production efficiency can be obtained without increasing the number of parts.

[0060] The power conversion device 100 has one or more slit partitions 6 in the region where the refrigerant flow path 11 has slits 12. These slit partitions 6 are configured to extend along the first direction, separating one side and the other side of the second direction, with gaps on one side and another side of the first direction provided at one or more locations in the second direction. In this case, the refrigerant can be further divided, further preventing refrigerant already used in one cooling operation from passing through another cooling fin side. Therefore, it is possible to more effectively use refrigerant with uniform temperature to cool multiple first semiconductor elements 14 and multiple second semiconductor elements 15 separately. Furthermore, the slit partitions 6 are integrally formed with the substrate 2 or the flow path forming member 1a within the refrigerant flow path 11, thus enabling the acquisition of a power conversion device that is easy to manufacture and has improved production efficiency without increasing the number of components.

[0061] Viewed from a direction perpendicular to one side of the substrate 2, when the slit partition 6 is disposed between multiple semiconductor modules 3, the refrigerant does not flow through the portions where multiple first semiconductor elements 14 and multiple second semiconductor elements 15 are not disposed, thus effectively cooling the multiple first semiconductor elements 14 and multiple second semiconductor elements 15. Furthermore, when the wall 5 has multiple slits 12, and the slit partition 6 is provided at the dividing portions of the slits 12, the slit partition 6 can be easily integrated with the flow path forming member 1a, and the slit partition 6 can be integrated with the flow path forming member 1a with high strength.

[0062] When multiple first semiconductor elements 14 and multiple second semiconductor elements 15 are arranged in a row, the refrigerant flowing directly below one semiconductor element to cool it does not flow directly below other semiconductor elements to cool them. Therefore, a refrigerant with a uniform temperature can be used to cool the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 respectively. Furthermore, when the number of multiple first semiconductor elements 14 and multiple second semiconductor elements 15 is equal, the difference in the degree of heating of each of the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 is reduced. Therefore, a refrigerant with a uniform temperature can be used to cool the multiple first semiconductor elements 14 and multiple second semiconductor elements 15 respectively.

[0063] The power conversion device 100 includes a first cooling fin 4a disposed on a portion of the other side of the substrate 2 that overlaps with at least a plurality of first semiconductor elements 14 when viewed from a direction perpendicular to the other side of the substrate 2, and a second cooling fin 4b disposed on a portion of the other side of the substrate 2 that overlaps with at least a plurality of second semiconductor elements 15 when viewed from a direction perpendicular to the other side of the substrate 2. In this case, the heat dissipation of the first semiconductor elements 14 and the second semiconductor elements 15 can be improved. Furthermore, when the substrate 2 is formed in the shape of a rectangular plate and the sides of one side of the substrate 2 are arranged parallel to a first direction or a second direction, the first semiconductor elements 14 and the second semiconductor elements 15 can be effectively arranged on one side of the substrate 2, thereby miniaturizing the power conversion device 100.

[0064] Implementation method 2.

[0065] The power conversion device 100 according to Embodiment 2 will be described. Figure 8 This is a top view of the power conversion device 100 according to Embodiment 2. Figure 9 This is a top view of another power conversion device 100 involved in Embodiment 2. Figure 8 and Figure 9 This diagram shows the power conversion device 100 after removing the substrate 2 and the semiconductor module 3. The power conversion device 100 according to Embodiment 2 differs from the power conversion device 100 shown in Embodiment 1 in that the width of the slit 12 is different.

[0066] exist Figure 8 and Figure 9In the power conversion device 100 shown, slit 12 is a supply port for supplying refrigerant to the refrigerant flow path 11, and through hole 8 is a discharge port for discharging refrigerant from the refrigerant flow path 11. Slit 12 has a wider width on one side in the second direction than on the other side. Slit 12 is a supply port, and refrigerant flows in the second direction, so that refrigerant is supplied to slit 12 from the left side of the figure. Therefore, at slit 12a on the left side of the figure, the refrigerant pressure tends to increase. With the same width of slit 12, more refrigerant may flow through the portion of slit 12 where the refrigerant pressure increases. By making the width of slit 12 larger on one side in the second direction than on the other side, an equal amount of refrigerant can flow through each portion of the refrigerant flow path 11. When an equal amount of refrigerant flows through each portion of the refrigerant flow path 11, refrigerant with a more uniform temperature can be used to cool the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 respectively.

[0067] The width of slit 12 is continuously or stepwise wider on the side facing the second direction than on the other side of the second direction. Figure 8 The width of the slit 12 shown continuously increases, while Figure 9 The width of the slit 12 shown increases in a stepped manner. With this structure, it is easy to form a slit 12 on the wall 5 that has a wider width on one side in the second direction than on the other side in the second direction. Furthermore, when the refrigerant flow path 11 has a slit partition 6, an equal amount of refrigerant can easily flow through each part of the refrigerant flow path 11 after being partitioned by the slit partition 6.

[0068] Implementation method 3.

[0069] The power conversion device 100 according to Embodiment 3 will be described. Figure 10 This is a top view of the power conversion device 100 according to Embodiment 3. Figure 11 Is Figure 10 A cross-sectional view of the power conversion device 100 cut off at the CC section position. Figure 12 This is a bottom view of the power conversion device 100. Figure 13 This is a bottom view of another power conversion device 100 according to Embodiment 3. The power conversion device 100 according to Embodiment 3 is configured to include a smoothing capacitor 10 and a cooling jacket 7.

[0070] Smoothing capacitor 10 Figure 10 As shown, it is housed in the housing 1 and thermally connected to the flow path forming member 1a. The smoothing capacitor 10 is electrically connected to each of the three semiconductor modules 3. The smoothing capacitor 10 is a capacitor that smooths the DC power disposed between the power supply and the semiconductor modules 3.

[0071] Cooling housing 7 Figure 11 As shown, a second refrigerant flow path 7a is formed on the opposite side of the refrigerant flow path 11 side of the flow path forming member 1a. This second refrigerant flow path 7a has a portion, i.e., a first portion, opposite to the portion of the flow path forming member 1a where the smoothing capacitor 10 is located, and a portion, i.e., a second portion, opposite to the portion of the flow path forming member 1a where the refrigerant flow path 11 is located. The second refrigerant flow path 7a formed in the second portion is connected to at least one of the slit 12 and the through hole 8. Because the second refrigerant flow path 7a is connected to one of the slit 12 and the through hole 8, the second refrigerant flow path 7a communicates with the refrigerant flow path 11. Figure 12 In the power conversion device 100 shown, slit 12 is connected to the second refrigerant flow path 7a. Figure 13 In the power conversion device 100 shown, the second refrigerant flow path 7a is connected to the slit 12 and the through hole 8. With this structure, the smoothing capacitor 10, the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15 can be cooled respectively by the refrigerant flowing continuously in the second refrigerant flow path 7a and the refrigerant flow path 11.

[0072] The cooling housing 7 is made of aluminum, for example. The cooling housing 7 is formed, for example, by stamping, from a single plate having recesses and protrusions. By constructing the cooling housing 7 from a single component, the cost of the power conversion device 100 can be reduced. A second refrigerant flow path 7a and a non-flow path portion 7b, which is not part of the second refrigerant flow path 7a, are formed on the cooling housing 7 through the recesses and protrusions. The cooling housing 7 is mounted to the flow path forming member 1a at the non-flow path portion 7b. The installation of the cooling housing 7 is performed, for example, by sealant and screws, to seal the refrigerant. By mounting the cooling housing 7 onto the flow path forming member 1a, a second refrigerant flow path 7a communicating with the refrigerant flow path 11 is formed. The cooling housing 7 has an inlet 7c for supplying refrigerant to the second refrigerant flow path 7a and an outlet 7d for discharging refrigerant. The refrigerant flowing into the second refrigerant flow path 7a from the inlet 7c flows into the refrigerant flow path 11 from the slit 12 or the through hole 8 after passing through the side (first part) of the flow path forming member 1a of the thermal connection of the smooth capacitor 10.

[0073] right Figure 12The flow of refrigerant in the power conversion device 100 shown will be explained. Refrigerant flows from inlet 7c into the second refrigerant flow path 7a, flows through the first section, and first cools the smoothing capacitor 10. Refrigerant flows from the second section into the refrigerant flow path 11 via slit 12, and uses refrigerant with uniform temperature to cool multiple first semiconductor elements 14 and multiple second semiconductor elements 15 respectively. The refrigerant is discharged to the outside via through-hole 8 and outlet 7d. The flow of refrigerant in refrigerant flow path 11 is related to… Figure 2 The refrigerant flow is the same as shown.

[0074] right Figure 13 The flow of refrigerant in the power conversion device 100 shown will be explained. Refrigerant flows into the second refrigerant flow path 7a from the inlet 7c, flows through the first section, and first cools the smoothing capacitor 10. Refrigerant flows into the refrigerant flow path 11 through the through-hole 8, using refrigerant with uniform temperature to cool multiple first semiconductor elements 14 and multiple second semiconductor elements 15 respectively. Refrigerant flows into the second section through the slit 12. Refrigerant is discharged to the outside through the outlet 7d. The flow of refrigerant in the refrigerant flow path 11 is related to… Figure 5 The refrigerant flow is the same as shown.

[0075] Typically, the heat generated in the smoothing capacitor 10 is less than the heat generated in the plurality of first semiconductor elements 14 and the plurality of second semiconductor elements 15. Therefore, since the temperature rise of the refrigerant after cooling the smoothing capacitor 10 is relatively small, the cooling of the entire power conversion device can be optimized by cooling the semiconductor elements after cooling the smoothing capacitor 10, which serves as the flow path for the refrigerant in the power conversion device 100.

[0076] exist Figure 12 In the power conversion device 100 shown, a refrigerant outlet 7d is formed on the cooling housing 7, serving as the refrigerant outlet for the power conversion device 100, but this is not a limitation. Alternatively, the refrigerant can be discharged directly to the outside from the through hole 8. Figure 13 In the power conversion device 100 shown, a discharge port 7d, serving as a refrigerant discharge port for the power conversion device 100, is formed on the cooling housing 7, but this is not a limitation. Alternatively, the refrigerant can be discharged directly to the outside from a portion of the slit 12. Figure 13 In the power conversion device 100 shown, when refrigerant is directly discharged to the outside from a portion of the slit 12, the second refrigerant flow path 7a is only connected to the through hole 8. This is because no second refrigerant flow path 7a is formed between the slit 12 and the discharge port 7d.

[0077] 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.

[0078] 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.

[0079] Label Explanation

[0080] 1. Housing, 1a. Flow path forming member, 1b. Side wall, 2. Substrate, 3. Semiconductor module, 4a. First cooling fin, 4b. Second cooling fin, 5. Wall, 6. Slit partition, 7. Cooling shell, 7a. Second refrigerant flow path, 7b. Non-flow path section, 7c. Inlet, 7d. Outlet, 8. Through hole, 9. Partition, 10. Smoothing capacitor, 11. Refrigerant flow path, 12. Slit, 12a, 12b, 12c. Slit, 13a, 13b, 13c, 13d. Semiconductor element, 14. First semiconductor element, 15. Second semiconductor element, 20. Insulating material, 21. Conductive member, 22. Solder, 23. Sealing member, 100. Power conversion device, 110. Refrigerant flow path, 200. Power conversion device.

Claims

1. A power conversion device, characterized in that, include: A substrate formed in the shape of a plate; A plurality of first semiconductor elements are arranged on one side of the first direction on one side of the substrate and along the second direction, when a specific direction parallel to one surface of the substrate is designated as the first direction and a direction orthogonal to the first direction parallel to one surface of the substrate is designated as the second direction. A plurality of second semiconductor elements are arranged along the second direction on the other side of the first direction on one side of the substrate. as well as A flow path forming member has a wall spaced apart from another side of the substrate and forms a refrigerant flow path for refrigerant to flow in the space. When viewed from a direction perpendicular to one side of the substrate, between the plurality of first semiconductor elements and the plurality of second semiconductor elements, the wall has one or more slits extending through the wall and in the second direction; And a through hole penetrating the wall at a portion of the wall that is closer to the second direction than the slit. The refrigerant flow path includes a partition that extends along the first direction, having a gap on one side of the first direction and a gap on the other side of the first direction, and separates the slit from the through hole. One of the slit and the through hole is a supply port for providing refrigerant to the refrigerant flow path. The other of the slit and the through hole is the outlet from which refrigerant is discharged from the refrigerant flow path. The refrigerant flow path has one or more slit partitions that extend along the first direction in one or more locations in the second direction in the region where the slits are provided, and with a gap on one side of the first direction and a gap on the other side of the first direction provided, thereby separating one side and the other side of the second direction.

2. The power conversion device as described in claim 1, characterized in that, It includes multiple semiconductor modules, each semiconductor module being formed from one or more first semiconductor elements and one or more second semiconductor elements. Multiple semiconductor modules are thermally connected to one side of the substrate and arranged in the second direction. When viewed from a direction perpendicular to one side of the substrate, the slit partition is disposed between multiple semiconductor modules.

3. The power conversion device as described in claim 1 or 2, characterized in that, The wall has the slits divided into a plurality of slits. The slit divider is provided at the dividing part of the slit.

4. The power conversion device according to any one of claims 1 to 3, characterized in that, The slit is a supply port for supplying refrigerant into the refrigerant flow path, and the through hole is a discharge port for discharging refrigerant from the refrigerant flow path. The slit has a wider width on one side of the second direction than on the other side of the second direction.

5. The power conversion device as described in claim 4, characterized in that, The width of the slit is continuously or stepwise wider on one side toward the second direction than on the other side of the second direction.

6. The power conversion device according to any one of claims 1 to 5, characterized in that, The plurality of first semiconductor elements and the plurality of second semiconductor elements are respectively arranged in a row.

7. The power conversion device according to any one of claims 1 to 6, characterized in that, The plurality of first semiconductor elements and the plurality of second semiconductor elements each have the same number.

8. The power conversion device according to any one of claims 1 to 7, characterized in that, include: A housing having the flow path forming member and accommodating the substrate, a plurality of first semiconductor elements, and a plurality of second semiconductor elements; A smoothing capacitor, which is housed in the housing and thermally connected to the flow path forming member; as well as A cooling housing is disposed on the opposite side of the refrigerant flow path side of the flow path forming member, forming a second refrigerant flow path for refrigerant flow in the space between the cooling housing and the flow path forming member. The second refrigerant flow path is connected to one of the slit and the through hole.

9. The power conversion device as described in claim 8, characterized in that, After the refrigerant flowing into the second refrigerant flow path passes through the second refrigerant flow path side of the flow path forming member that is thermally connected to the smooth capacitor, it flows into the refrigerant flow path from the slit or the through hole.

10. The power conversion device according to any one of claims 1 to 9, characterized in that, include: A first cooling fin, when viewed from a direction perpendicular to another side of the substrate, is disposed on at least a portion of the other side of the substrate that overlaps with a plurality of the first semiconductor elements; and The second cooling fin, when viewed from a direction perpendicular to the other side of the substrate, is disposed on at least the portion of the other side of the substrate that overlaps with a plurality of the second semiconductor elements.

11. The power conversion device according to any one of claims 1 to 10, characterized in that, The substrate is formed in the shape of a rectangular plate, and each side of one side of the substrate is arranged parallel to the first direction or the second direction.

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