Cooling device, semiconductor module, and vehicle

Abstract

In order to solve the problem of stress generation in the fastening portion where a cooling device is fastened to a semiconductor module or the like, the present invention provides a cooling device, a semiconductor module, and a vehicle. The cooling device is a cooling device for a semiconductor module including a semiconductor chip, and includes: a top plate having a lower surface; a housing portion including a coolant flow portion and an outer edge portion surrounding the coolant flow portion, the coolant flow portion being disposed on the lower surface side of the top plate, and the housing portion being disposed in direct or indirect contact with the lower surface of the top plate at the outer edge portion; and cooling fins disposed in the coolant flow portion. The top plate and the housing portion have a fastening portion for fastening the top plate and the housing portion to an external device, and the top plate and the outer edge portion are overlapped and disposed at the fastening portion. Further, a reinforcing member is provided between the top plate and the housing portion at the fastening portion.

Description

Technical Field

[0001] The present invention relates to a cooling device, a semiconductor module, and a vehicle. Background Art

[0002] Conventionally, a structure in which a cooling device is provided in a semiconductor module including semiconductor elements such as power semiconductor chips has been known (for example, refer to Patent Documents 1 to 4).

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-220382

[0004] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-324647

[0005] Patent Document 3: WO2016 / 204257

[0006] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2014-179563 Summary of the Invention

[0007] Technical Problem

[0008] If the temperature of the cooling device changes due to a change in the ambient temperature or heat generation of the semiconductor device, etc., stress is applied to the fastening portion for fastening the cooling device to an external device or the like.

[0009] Technical Solution

[0010] To solve the above problems, in a first aspect of the present invention, there is provided a cooling device for a semiconductor module including a semiconductor chip. The cooling device may include a top plate having a lower surface. The cooling device may include a housing portion including a coolant flow portion and an outer edge portion surrounding the coolant flow portion. The coolant flow portion is disposed on the lower surface side of the top plate, and the housing portion is disposed in direct or indirect contact with the lower surface of the top plate at the outer edge portion. The cooling device may include cooling fins disposed in the coolant flow portion. The top plate and the housing portion may have a fastening portion for fastening the top plate and the housing portion to an external device, and the top plate and the outer edge portion are disposed overlapping each other at the fastening portion. The cooling device may include a reinforcing member at the fastening portion, and the reinforcing member is provided between the top plate and the outer edge portion.

[0011] The fastening portion may protrude outward from the outer periphery of the top plate.

[0012] The top plate may have two pairs of opposite sides and four corners when viewed from above. The fastening portion may be provided to protrude outward in the circumferential direction of the outer periphery of the top plate at at least one corner. The housing portion may include a bottom plate having four corners, a coolant flow portion may be disposed between the bottom plate and the lower surface of the top plate, and an opening portion for connecting the coolant flow portion to the outside may be provided at at least one corner of the bottom plate. The corner of the top plate where the fastening portion is provided and the corner of the bottom plate where the opening portion is provided may be disposed at opposite positions.

[0013] The top plate may have a pair of opposite long sides and a pair of opposite short sides when viewed from above. The fastening portion may be provided at two corners, namely, a first corner where the opening portion is provided and a second corner where the opening portion is not provided. The first fastening portion at the first corner may be provided to protrude in a direction parallel to the long side. The second fastening portion at the second corner may be provided to protrude in a direction different from that of the first fastening portion.

[0014] A plurality of reinforcing members may be stacked on the fastening portion.

[0015] The top plate may have a side surface along the outer periphery. The reinforcing member may have an inner side surface opposite to the coolant flow portion and an outer side surface opposite to the inner side surface. The outer side surface of the reinforcing member and the side surface of the top plate may be disposed flush with each other.

[0016] The reinforcing member may be formed of a material having an elastic limit stress higher than the elastic limit stresses of the top plate and the housing portion.

[0017] The thickness at a position of the housing portion opposite to the center of the lower surface of the top plate may be the same as the thickness at the fastening portion of the housing portion.

[0018] At the fastening portion, the reinforcing member, the top plate, and the housing portion may have the same thickness.

[0019] In other examples of the first mode, the cooling device may include a top plate having an upper surface and a lower surface opposite to the upper surface, on which a semiconductor chip can be mounted. The cooling device may include a reinforcing member disposed along the outer periphery of the lower surface of the top plate. The cooling device may include a housing portion that includes a coolant flow portion disposed on the lower surface side of the top plate. The cooling device may include cooling fins disposed in the coolant flow portion. The cooling device may include a fastening portion. The housing portion may have a frame portion, a bottom plate, and side walls. The frame portion may have an upper surface and a lower surface opposite to the upper surface, and the upper surface is disposed in direct or indirect contact with the lower surface of the top plate. The bottom plate may have corners and openings provided at the corners, and a coolant flow portion is disposed between the bottom plate and the lower surface of the top plate. The side walls may connect the inner side surface of the frame portion to the periphery of the bottom plate and define a coolant flow portion between the top plate and the bottom plate. The fastening portion may be provided to protrude outward on the outer periphery of the top plate to the opposite side of the openings and the corners of the bottom plate. In the fastening portion, the frame portion, the reinforcing member, and the top plate are stacked in sequence, and the fastening portion may have a through hole passing through the frame portion, the reinforcing member, and the top plate.

[0020] A pipe may be connected to the opening of the bottom plate of the housing portion, and the pipe protrudes to the opposite side of the cooling fins.

[0021] The reinforcing member may be disposed between the top plate and the housing portion to surround the coolant flow portion on the lower surface of the top plate.

[0022] The reinforcing member may be provided inside the coolant flow portion.

[0023] In a plan view, the length by which the reinforcing member protrudes into the coolant flow portion in the region opposite to the opening may be greater than the length by which the reinforcing member protrudes into the coolant flow portion in the region opposite to the cooling fins.

[0024] In a second aspect of the present invention, a cooling device for a semiconductor module including a semiconductor chip is provided. The cooling device may include a top plate having an upper surface and a lower surface opposite to the upper surface, and the semiconductor chip can be mounted on the upper surface. The cooling device may include a reinforcing member disposed along the outer periphery of the lower surface of the top plate. The cooling device may include a housing portion disposed with a coolant flow portion between the housing portion and the top plate. The cooling device may include cooling fins disposed in the coolant flow portion. The cooling device may include a fastening portion. The housing portion may include a frame portion having an upper surface and a lower surface opposite to the upper surface, and the upper surface may be disposed in direct or indirect contact with the lower surface of the top plate. The housing portion may include a bottom plate disposed with a coolant flow portion between the bottom plate and the lower surface of the top plate, and the bottom plate has corners with openings provided at the corners. The housing portion may include side walls connecting the inner side surface of the frame portion to the periphery of the bottom plate and defining a coolant flow portion between the top plate and the bottom plate. The fastening portion may be provided to protrude outward from the outer periphery of the top plate to the outside opposite to the openings and the corners of the bottom plate. In the fastening portion, the frame portion, the reinforcing member, and the top plate are stacked in sequence, and the fastening portion may have a through hole penetrating the frame portion, the reinforcing member, and the top plate.

[0025] A tube may be connected to the opening of the bottom plate of the housing portion, and the tube protrudes to the side opposite to the cooling fins.

[0026] In a third aspect of the present invention, a semiconductor module is provided, which includes the cooling device according to the first or second aspect and a semiconductor device mounted above the top plate.

[0027] In a fourth aspect of the present invention, a vehicle including the semiconductor module according to the third aspect is provided.

[0028] It should be noted that the above description of the invention does not list all the necessary features of the present invention. In addition, sub-combinations of these feature groups can also form inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. 18 is a schematic cross-sectional view showing an example of a semiconductor module 100 according to an embodiment of the present invention.

[0030] Figure 2A FIG. 22 is a view showing an example of the shape of the top plate 20 when viewed from the upper surface (xy plane).

[0031] Figure 2B FIG. 26 is a view for explaining the protruding direction of the fastening portion 81.

[0032] Figure 3 FIG. 30 is a view showing an example of the shape of the housing portion 40 when viewed from the upper surface (xy plane).

[0033] Figure 4 This is a diagram showing an example of the shape of the reinforcing member 30 when viewed from the upper surface (xy plane).

[0034] Figure 5 This is a perspective view showing the top plate 20, the reinforcing member 30, and the housing portion 40 separately.

[0035] Figure 6 This is a diagram showing a cross-section of another example of the cooling device 10.

[0036] Figure 7 This is a diagram showing a cross-section of another example of the cooling device 10.

[0037] Figure 8 This is a top view showing an example of the arrangement of the inner side surface 34 of the reinforcing member 30.

[0038] Figure 9 This is a diagram showing another example of the shapes of the housing portion 40 and the reinforcing member 30.

[0039] Figure 10 This is a diagram showing an overview of the vehicle 200 according to an embodiment of the present invention.

[0040] Figure 11 This is a main circuit diagram of the semiconductor module 100 according to an embodiment of the present invention.

[0041] Reference Signs

[0042] 10: Cooling device, 11: Outer side surface, 12: Upper surface, 13: Inner side surface, 16: Upper surface, 19: Corner portion, 20: Top plate, 22: Upper surface, 24: Lower surface, 26: Short side, 27: Side surface, 28: Long side, 29: Corner portion, 30: Reinforcing member, 34: Inner side surface, 36: Outer side surface, 40: Housing portion, 41: Outer edge portion, 42: Opening portion, 62: Frame portion, 63: Side wall, 64: Bottom plate, 65: Extension line, 70: Semiconductor device, 72: Accommodating portion, 74: Sealing portion, 76: Circuit board, 78: Semiconductor chip, 79: Through hole, 80: Fastening portion, 81: Fastening portion, 82: Through hole, 83: Fastening portion, 84: Through hole, 85: Fastening portion, 86: Through hole, 88: Outer periphery, 90: Pipe, 92: Coolant flow portion, 94: Cooling fin, 95: Vertex, 96: Position, 100: Semiconductor module, 200: Vehicle, 210: Control device Detailed Embodiments

[0043] Hereinafter, the present invention will be described by way of embodiments of the invention. However, the following embodiments do not limit the invention claimed. In addition, not all of the feature combinations described in the embodiments are necessarily required for the solution of the invention.

[0044] Figure 1 FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor module 100 according to an embodiment of the present invention. The semiconductor module 100 includes a semiconductor device 70 and a cooling device 10. In this example, the semiconductor device 70 is mounted on the cooling device 10. In this specification, the surface of the cooling device 10 on which the semiconductor device 70 is mounted is defined as the xy plane, and the direction perpendicular to the xy plane is defined as the z-axis. In this specification, the direction from the cooling device 10 toward the semiconductor device 70 in the z-axis direction is referred to as up, and the opposite direction is referred to as down. The up and down directions are not limited to the direction of gravity. In addition, in this specification, the upper surface among the surfaces of each component is referred to as the upper surface, the lower surface is referred to as the lower surface, and the surface between the upper surface and the lower surface is referred to as the side surface.

[0045] The semiconductor device 70 includes one or more semiconductor chips such as power semiconductor chips 78. As an example, an insulated gate bipolar transistor (IGBT) formed on a semiconductor substrate such as silicon is provided in the semiconductor chip 78.

[0046] The semiconductor device 70 has a circuit board 76 and a housing portion 72. As an example, the circuit board 76 is a board on which a circuit pattern is provided on an insulating substrate. The semiconductor chip 78 is fixed to the circuit board 76 via solder or the like. The housing portion 72 is formed of an insulating material such as resin. The housing portion 72 has an internal space for housing the semiconductor chip 78, the circuit board 76, wirings, and the like. A sealing portion 74 for sealing the semiconductor chip 78, the circuit board 76, wirings, and the like may be filled in the internal space of the housing portion 72. The sealing portion 74 is an insulating member such as silicone gel or epoxy resin, for example.

[0047] The cooling device 10 has a top plate 20, a housing portion 40, and a reinforcing member 30. The top plate 20 may be a plate-shaped metal plate having an upper surface 22 parallel to the xy plane and a lower surface 24. As an example, the top plate 20 is formed of a metal containing aluminum. The semiconductor device 70 is mounted on the upper surface 22 of the top plate 20. The heat generated by the semiconductor chip 78 is transferred to the top plate 20. For example, heat-conductive components such as the circuit board 76, a metal plate, and solder are disposed between the top plate 20 and the semiconductor chip 78. The circuit board 76 may be directly fixed to the upper surface 22 of the top plate 20 via solder or the like. In this case, the housing portion 72 is provided so as to surround the region where the circuit board 76 and the like are disposed on the upper surface 22 of the top plate 20. In other examples, the semiconductor device 70 may also have a metal plate exposed on the lower surface of the housing portion 72, the circuit board 76 is fixed to the upper surface of the metal plate, and the metal plate is fixed to the upper surface of the top plate 20.

[0048] The housing part 40 includes a coolant flow part 92 and an outer edge part 41 that surrounds the coolant flow part 92 in the xy plane. The coolant flow part 92 is arranged on the lower surface 24 side of the top plate 20. The coolant flow part 92 is an area where a coolant such as water flows. The coolant flow part 92 can be an enclosed space that abuts against the lower surface 24 of the top plate 20. In addition, the housing part 40 is arranged in direct or indirect contact with the lower surface 24 of the top plate 20 at the outer edge part 41, and the outer edge part 41 surrounds the coolant flow part 92 in the xy plane. Thereby, the coolant flow part 92 is sealed. It should be noted that indirect contact means a state in which the lower surface 24 of the top plate 20 and the housing part 40 are in contact via a sealing material, adhesive, or other components provided between the lower surface 24 of the top plate 20 and the housing part 40. Contact means a state in which the coolant inside the coolant flow part 92 does not leak from the contact part. Cooling fins 94 are provided inside the coolant flow part 92. The cooling fins 94 can be connected to the lower surface 24 of the top plate 20. By passing the coolant near the cooling fins 94, the heat generated by the semiconductor chip 78 is transferred to the coolant. Thereby, the semiconductor device 70 can be cooled. The housing part 40 of this example has a frame part 62, a bottom plate 64, and a side wall 63. The outer edge part 41 can at least include the frame part 62.

[0049] The frame part 62 is arranged to surround the coolant flow part 92 in the xy plane. The upper surface 16 of the frame part 62 is arranged in direct or indirect contact with the lower surface 24 of the top plate 20. That is, the upper surface 16 of the frame part 62 and the lower surface 24 of the top plate 20 are arranged in a manner that seals the coolant flow part 92. A sealing material or other components can also be provided between the upper surface 16 of the frame part 62 and the lower surface 24 of the top plate 20. In Figure 1 In the shown cross-section, a reinforcing member 30 is provided between the upper surface 16 of the frame part 62 and the lower surface 24 of the top plate 20. That is, the reinforcing member 30 can be provided on the upper surface 16 of the frame part 62, or the top plate 20 can be provided on the upper surface 12 of the reinforcing member 30.

[0050] In this example, each of the components such as the top plate 20, the housing part 40, and the reinforcing member 30 is brazed together. As an example, the top plate 20, the housing part 40, and the reinforcing member 30 are formed of metals having the same composition, and the brazing material is formed of a metal having a melting point lower than that of the top plate 20 or the like. As the metal, a metal containing aluminum can be used. As the metal containing aluminum, aluminum alloys such as Al-Mn alloys (3000 series aluminum alloys) and Al-Mg-Si alloys (6000 series aluminum alloys) can be used. As the brazing material, aluminum alloys such as Al-Si alloys (4000 series aluminum alloys) can be used. Preferably, the aluminum alloy used in this example has an elastic limit stress at room temperature in the range of 35 to 65 MPa. The elastic limit stress refers to the stress that causes a 0.2% permanent deformation after unloading the load.

[0051] The bottom plate 64 is configured to have a coolant flow portion 92 between the bottom plate 64 and the lower surface 24 of the top plate 20. In the bottom plate 64 of this example, two or more openings 42 for introducing or discharging coolant with respect to the coolant flow portion 92 are provided. The opening 42 is connected to a pipe 90 for transporting coolant. The pipe 90 protrudes from the bottom plate 64 toward the opposite side of the cooling fins 94 (in this example, the negative z-axis side).

[0052] The side wall 63 divides the coolant flow portion 92 by connecting the frame portion 62 and the bottom plate 64. In the side wall 63 of this example, the inner side surface 13 of the frame portion 62 is connected to the periphery of the bottom plate 64. The inner side surface 13 of the frame portion 62 is the side surface facing the coolant flow portion 92. The periphery of the bottom plate 64 is the outer peripheral portion of the bottom plate 64 in the xy plane.

[0053] The top plate 20 and the housing portion 40 have a fastening portion 80 for fastening each other. The fastening portion 80 can also be used to fix the semiconductor module 100 to an external device. As an example, the fastening portion 80 is a region where the top plate 20 and the housing portion 40 are directly or indirectly in close contact and are arranged overlappingly in the z-axis direction, and is a region where a through hole 79 penetrating the top plate 20 and the housing portion 40 is formed. In Figure 1 it, the regions of the top plate 20 and the housing portion 40 where the through hole 79 is formed are indicated by dotted lines. The fastening portion 80 of this example is provided in the frame portion 62.

[0054] In the fastening portion 80, a reinforcing member 30 is provided between the top plate 20 and the housing portion 40. The top plate 20 and the reinforcing member 30 are arranged in close contact with each other, and the reinforcing member 30 and the housing portion 40 are arranged in close contact with each other. In this example, these members are brazed as described above. In addition, the through hole 79 is provided so as to also penetrate the reinforcing member 30.

[0055] By providing the reinforcing member 30 in the fastening portion 80, the strength of the fastening portion 80 where stress is likely to concentrate can be improved. In addition, by providing the reinforcing member 30, the total thickness of the metal plate at the fastening portion 80 in the z-axis direction can be increased without increasing the thickness of the side wall 63 and the bottom plate 64, and the strength of the fastening portion 80 can be improved. By not increasing the thickness of the side wall 63 and the bottom plate 64, the side wall 63 and the bottom plate 64 can be deformed relatively easily with respect to stress. Therefore, even if, for example, the coolant, cooling fins, etc. inside the coolant flow portion 92 expand or contract according to temperature changes, the volume change is easily absorbed by the deformation of the side wall 63 and the bottom plate 64. In addition, even when a force is applied to the housing portion 40 when the pipe 90 is connected to the opening 42, the force is easily absorbed by the side wall 63 and the bottom plate 64. Therefore, the fastening portion 80 can be protected.

[0056] The reinforcing member 30 can be provided in the xy plane from the region where the through-hole 79 is provided to the position opposite to the side wall 63 of the housing portion 40. Thereby, deformation of the frame portion 62 at the position opposite to the side wall 63 can be prevented, and stress concentration at the connection portion between the side wall 63 and the frame portion 62 can be prevented. Thereby, the side wall 63 can be protected. The side wall 63 and the inner side surface 13 of the reinforcing member 30 can be arranged flush.

[0057] The fastening portion 80 is provided to protrude more outward than the side wall 63. It should be noted that the outer side refers to the direction away from the center of the coolant flow portion 92 in the xy plane. In addition, the fastening portion 80 is provided to protrude more outward than the housing portion 72. That is, the fastening portion 80 has a structure of a cantilever beam whose front end in the xy plane is not supported by other components of the semiconductor module 100. Therefore, the fastening portion 80 is relatively easy to deform, but by providing the reinforcing member 30, the strength of the fastening portion 80 can be improved.

[0058] The reinforcing member 30 can also be formed of a material having an elastic limit stress higher than that of the top plate 20 and the housing portion 40. As an example of such a material, an aluminum alloy having an elastic limit stress of 50 MPa or more is listed, and an aluminum alloy having an elastic limit stress of 50 to 65 Mpa is preferably used. Thereby, the strength of the fastening portion 80 can be further improved.

[0059] Figure 2A It is a view showing an example of the shape of the top plate 20 in a plan view (xy plane). The top plate 20 has two pairs of opposite sides 26 and 28 in a plan view. The top plate 20 in this example has a substantially rectangular shape with a short side 26 and a long side 28. The top plate 20 has four corner portions 29. In this specification, the direction in which the short side 26 extends is set as the y-axis, and the direction in which the long side 28 extends is set as the x-axis.

[0060] In addition, the outer periphery 88 of the rectangle defined by the long side 28 and the short side 26 is set as the outer periphery of the top plate 20. That is, the shape of the outer periphery 88 is a shape obtained by replacing the unevenness of the long side 28 and the short side 26 of the top plate 20 with the extension lines of the long side 28 and the short side 26. In Figure 2A the outer periphery 88 is indicated by a dotted line.

[0061] The corner portion 29 refers to the region near each vertex on the outer periphery 88 of the top plate 20. As an example, as Figure 2A shown by a one-dot chain line in, four regions located at the corners of the outer periphery 88 obtained by equally dividing the outer periphery 88 of the top plate 20 into four equal parts on the x-axis and the y-axis are used as the corner portions 29. In this example, the corner portion 29 arranged opposite to the opening portion 42 of the housing portion 40 is set as the first corner portion 29-1, and the other corner portions 29 are set as the second corner portions 29-2. The first corner portion 29-1 may include the entire region opposite to the opening portion 42 or may include only a part thereof. In Figure 2AIn FIG. 4 , a region facing the opening 42 is indicated by a dotted line.

[0062] The top plate 20 is provided with Figure 1 The fastening portion 80 shown in the figure has one or more fastening portions 81 as a part of the fastening portion 80. At least one fastening portion 81 may be provided at the corner portion 29. In this example, the fastening portion 81 is provided at all the corner portions 29. In addition, the fastening portion 81 may be provided at each long side 28, or it may not be provided. The fastening portion 81 may be provided at each short side 26, or it may not be provided.

[0063] Each fastening portion 81 is provided on the outer periphery 88 of the top plate 20 so as to protrude outward from the outer periphery 88. The outer side in this example refers to a direction away from the center of the top plate 20 in the xy plane. Each fastening portion 81 has a Figure 1 The through hole 82 shown is a part of the through hole 79. The through hole 82 may be arranged outside the outer periphery 88, may be arranged inside the outer periphery 88, or may be arranged overlapping with the outer periphery 88.

[0064] In this example, in the first fastening portion 81-1 of the first corner portion 29-1, the entire through hole 82 is arranged at a position outside the outer periphery 88. In the second fastening portion 81-2 of the second corner portion 29-2 and the third fastening portion 81-3 of each side, the through hole 79 may be arranged inside the outer periphery 88, or may be arranged to overlap the outer periphery 88. The pipe 90 is connected to the opening portion 42. By arranging the through hole 82 of the first fastening portion 81-1 outside the outer periphery 88, it is possible to facilitate the work of connecting the pipe 90 and the work of fastening a screw or the like to the through hole 82 of the first fastening portion 81-1.

[0065] In addition, preferably, the length of the first fastening portion 81-1 protruding outward from the outer periphery 88 is greater than the length of the other fastening portions 81 protruding outward from the outer periphery 88. Thus, the through hole 82 of the first fastening portion 81-1 can be arranged away from the opening 42. Figure 1 As described in , since the reinforcing member 30 is provided so as to overlap with the fastening portion 81, even if the protruding length of the first fastening portion 81-1 is increased, the strength can be maintained.

[0066] The first fastening portion 81-1 may be provided protruding from the periphery 88 in a direction parallel to the long side 28 (i.e., the x-axis direction) in the xy plane. Here, the parallel direction may include a predetermined error. For example, the long side 28 and the protruding direction of the first fastening portion 81-1 may have an inclination within 20 degrees. The protruding direction of the fastening portion 81 may be a direction that connects the vertex of the fastening portion 81 (the point farthest from the periphery 88) and the periphery 88 at the shortest distance. Figure 2AIn the figure, the direction in which a part of the fastening portion 81 protrudes is indicated by an arrow. Thus, even if the protruding length of the first fastening portion 81-1 is increased, it is possible to suppress the case where the top plate 20 becomes large in the y-axis direction.

[0067] In addition, the second fastening portion 81-2 may be provided to protrude in a direction different from that of the first fastening portion 81-1. In Figure 2A In the example, the second fastening portion 81-2 protrudes in a direction that is 45 degrees with respect to the y-axis. Since the protruding length of the second fastening portion 81-2 is relatively small, even if it protrudes in this direction, the top plate 20 does not become very large. In addition, the third fastening portion 81-3 protrudes from the outer periphery 88 in the y-axis direction. The length by which the second fastening portion 81-2 protrudes from the outer periphery 88 in the y-axis direction may be the same as the length by which the third fastening portion 81-3 protrudes from the outer periphery 88 in the y-axis direction. In Figure 2A In, the two first fastening portions 81-1 may be arranged symmetrically with respect to the center of the top plate 20 in the xy plane. Similarly, the two second fastening portions 81-2 may be arranged symmetrically with respect to the center of the top plate 20 in the xy plane.

[0068] Figure 2B is a diagram for explaining the protruding direction of the fastening portion 81. In Figure 2B In, the vicinity of the fastening portion 81-1 and the fastening portion 81-2 is shown enlarged. In Figure 2B In, the through holes 82 at each fastening portion 81 are omitted. In this example, at each protruding portion 81, the point in the xy plane that is farthest from the outer periphery 88 is set as the vertex 95. As described above, the protruding direction of the fastening portion 81 is the direction that connects the vertex 95 and the outer periphery 88 at the shortest distance. However, in the case where there are multiple vertices 95, such as the fastening portion 81-2, the direction that connects the average position 96 of the multiple vertices 95 in the xy coordinate space and the outer periphery 88 at the shortest distance may be set as the protruding direction of the fastening portion 81. The average position 96 of the multiple vertices 95 refers to the position that represents the average coordinate values of the multiple vertices 95 in the x coordinate and the y coordinate, respectively.

[0069] Figure 3 is a diagram showing an example of the shape of the housing portion 40 when viewed from above (xy plane). In this example, the outer shape of the housing portion 40 in the xy plane is the same as the outer shape of the top plate 20. In this example, the outer shape of the frame portion 62 corresponds to the outer shape of the housing portion 40. The frame portion 62 has an inner side surface 13 on the coolant flow portion 92 side and an outer side surface 11 on the opposite side of the inner side surface 13. Each side surface in this example is a surface that is substantially perpendicular to the xy plane. In Figure 3 In, the outer periphery 88 of the top plate 20 is shown overlapping the shape of the housing portion 40. In addition, the housing portion 40 also has corners 29 in the xy plane, just like the top plate 20.

[0070] At each corner portion 29 of the housing portion 40, a fastening portion 85 is provided in the same manner as the top plate 20. In addition, the fastening portion 85 may be provided on any side of the housing portion 40. The fastening portion 85 is provided so as to protrude more outward from the frame portion 62 than the outer periphery 88. In this example, the shape of each fastening portion 85 in the xy plane is the same as the shape of the opposing fastening portion 81. Each fastening portion 85 may be provided with a through hole 86. The through hole 86 is provided at a position overlapping with the Figure 2A shown through hole 82.

[0071] A bottom plate 64 is provided inside the frame portion 62 in the xy plane. The bottom plate 64 has four corner portions 19. The corner portions 19, similar to the corner portions 29, may be four corner regions among the 16 regions obtained by equally dividing the outer periphery of the bottom plate 64 on the x-axis and y-axis. The fastening portion 85 is provided so as to protrude outward from the outer periphery 88 of the top plate 20 to the side opposite to the opening portion 42 and the corner portion 19 of the bottom plate 64.

[0072] An opening portion 42 for connecting the coolant flow portion 92 to the outside may be provided at any corner portion 19 of the bottom plate 64. In the bottom plate 64 of this example, the opening portions 42 are respectively provided at two corner portions 19 arranged point-symmetrically with respect to the center of the bottom plate 64 in the xy plane. As Figure 2A and Figure 3 shown, the corner portion 29-1 of the top plate 20 provided with the fastening portion 81-1 and the corner portion 19-1 of the bottom plate 64 provided with the opening portion 42 are arranged at opposing positions.

[0073] In this example, using the relative positions on the x-axis and y-axis, each corner portion 19 is respectively set as the corner portion 19 on the positive side of the x-axis and on the positive side of the y-axis (in the example of Figure 3 it is the corner portion 19-1), the corner portion on the positive side of the x-axis and on the negative side of the y-axis (in the example of Figure 3 it is the corner portion 19-2), the corner portion on the negative side of the x-axis and on the positive side of the y-axis (in the example of Figure 3 it is the corner portion 19-2), and the corner portion 19 on the negative side of the x-axis and on the negative side of the y-axis (in the example of Figure 3 it is the corner portion 19-1). Similarly, using the relative positions on the x-axis and y-axis, each corner portion 29 is set as the corner portion 29 on the positive side of the x-axis and on the positive side of the y-axis (in the example of Figure 2A it is the corner portion 29-1), the corner portion on the positive side of the x-axis and on the negative side of the y-axis (in the example of Figure 2A it is the corner portion 29-2), the corner portion on the negative side of the x-axis and on the positive side of the y-axis (in the example of Figure 2A it is the corner portion 29-2), and the corner portion 29 on the negative side of the x-axis and on the negative side of the y-axis (in the example of Figure 3In the example, it is the corner part 29-1). The two opposite corner parts of the bottom plate 64 and the top plate 20 refer to the corner parts 19 and 29 corresponding to the relative positions of the x-axis and the y-axis. More specifically, the corner part 19 on the positive side of the x-axis and on the positive side of the y-axis is opposite to the corner part 29 on the positive side of the x-axis and on the positive side of the y-axis. The corner part 19 on the positive side of the x-axis and on the negative side of the y-axis is opposite to the corner part 29 on the positive side of the x-axis and on the negative side of the y-axis. The corner part 19 on the negative side of the x-axis and on the positive side of the y-axis is opposite to the corner part 29 on the negative side of the x-axis and on the positive side of the y-axis. The corner part 19 on the negative side of the x-axis and on the negative side of the y-axis is opposite to the corner part 29 on the negative side of the x-axis and on the negative side of the y-axis.

[0074] Figure 4 is a view showing an example of the shape of the reinforcing member 30 when viewed from above (xy plane). The reinforcing member 30 in this example is provided so as to surround Figure 1 the coolant flow passage portion 92 shown. The outer shape of the reinforcing member 30 in the xy plane is the same as the outer shape of the top plate 20. In Figure 4 it, the outer periphery 88 of the top plate 20 and the shape of the reinforcing member 30 are shown overlapping.

[0075] The reinforcing member 30 may have the same shape as the frame portion 62 of the housing portion 40 in the xy plane. The reinforcing member 30 is disposed between the upper surface 16 of the frame portion 62 and the lower surface 24 of the top plate 20. The reinforcing member 30 has an inner side surface 34 on the coolant flow passage portion 92 side and an outer side surface 36 on the opposite side of the inner side surface 34. The inner side surface 34 of the reinforcing member 30 may be disposed flush with the inner side surface 13 of the frame portion 62 of the housing portion 40. The outer side surface 36 of the reinforcing member 30 may be disposed flush with the outer side surface 11 of the frame portion 62 of the housing portion 40.

[0076] In addition, the reinforcing member 30 also has corner parts 29 in the xy plane in the same manner as the top plate 20. Fastening parts 83 are also provided at each corner part 29 of the reinforcing member 30 in the same manner as the top plate 20. In addition, fastening parts 83 may be provided on any side of the reinforcing member 30. In this example, the shape of each fastening part 83 in the xy plane is the same as the shape of the opposite fastening part 81. Through holes 84 are provided in each fastening part 83. The through holes 84 are provided at positions overlapping with Figure 2A the through holes 82 shown.

[0077] Figure 5 is a perspective view showing the top plate 20, the reinforcing member 30, and the housing portion 40 separately. As described above, the top plate 20, the reinforcing member 30, and the housing portion 40 may have substantially the same outer shape in the xy plane. The fastening parts of the top plate 20, the reinforcing member 30, and the housing portion 40 may have the same shape in the xy plane and be disposed overlappingly in the z-axis direction. In Figure 5In the figure, the overlapping positions when the top plate 20, the reinforcing member 30, and the housing portion 40 are fixed by brazing or the like are indicated by dashed lines. It should be noted that in Figure 5 the cooling fins 94 disposed in the coolant flow portion 92 are omitted. In addition, the brazing material between the respective components is also omitted.

[0078] As Figure 5 shown, the reinforcing member 30 is disposed so as to surround the coolant flow portion 92 between the top plate 20 and the housing portion 40, and seals the coolant flow portion 92. The frame portion 62 of the housing portion 40 is fixed to the top plate 20 via the reinforcing member 30. The housing portion 40 has a bottom plate 64 disposed apart from the top plate 20, and side walls 63 connecting the bottom plate 64 and the frame portion 62. The coolant flow portion 92 is defined by the lower surface 24 of the top plate 20, the inner side surface 34 of the reinforcing member 30, and the housing portion 40.

[0079] The fastening portion 80 is provided so as to protrude outward from the outer periphery 88 of the top plate 20 toward the side opposite to the corner portion 19 of the opening portion 42 and the bottom plate 64 (refer to Figure 3 ). In addition, in the fastening portion 80, the frame portion 62, the reinforcing member 30, and the top plate 20 are stacked in sequence, and have a through hole 79 (refer to Figure 1 ) that penetrates through the frame portion 62, the reinforcing member 30, and the top plate 20. The through holes 82, 84, and 86 can be provided coaxially with each other.

[0080] In addition, in the fastening portion 80, the top plate 20, the reinforcing member 30, and the housing portion 40 can have the same thickness. The top plate 20, the reinforcing member 30, and the housing portion 40 can also have the same thickness in regions other than the fastening portion 80.

[0081] In addition, the frame portion 62 and the side walls 63 of the housing portion 40 can be integrally provided. The frame portion 62 and the side walls 63 can be formed by forging a single plate-like metal. In addition, the bottom plate 64 can be integrally provided with the side walls 63 or can be brazed to the side walls 63. The bottom plate 64, the frame portion 62, and the side walls 63 can have the same thickness. As an example, the thickness of the bottom plate 64 at a position opposite to the center of the lower surface 24 of the top plate 20 can be the same as the thickness of the frame portion 62 at the fastening portion 80. By making the respective components have the same thickness, the cooling device 10 can be manufactured using a common metal coil.

[0082] Figure 6FIG. is a cross-sectional view of the cooling device 10 showing another example. The cooling device 10 of this example is provided by laminating a plurality of reinforcing members 30. The thickness of each reinforcing member 30 may be the same as the thickness of the top plate 20. The thicknesses of the plurality of laminated reinforcing members 30 may be the same. By adjusting the number of the reinforcing members 30, the thickness of the fastening portion 80 can be arbitrarily changed, and the strength of the fastening portion 80 can be adjusted. In other examples, one reinforcing member 30 may be provided between the top plate 20 and the housing portion 40, and the thickness of the fastening portion 80 can be adjusted by adjusting the thickness of the reinforcing member 30.

[0083] Figure 7 FIG. is a cross-sectional view of the cooling device 10 showing another example. In Figure 7 , the vicinity of the fastening portion 80 is shown enlarged. In this example, the top plate 20 has a side surface 27 along the outer periphery. As described above, the reinforcing member 30 has an inner side surface 34 facing the coolant flow portion 92 and an outer side surface 36 opposite to the inner side surface 34. In this example, the outer side surface 36 of the reinforcing member 30 is arranged flush with the side surface 27 of the top plate 20. The reinforcing member 30 of the cooling device 10 of this example is provided to extend into the interior of the coolant flow portion 92, which is different from the cooling devices 10 of the respective modes described in Figures 1 to 6 . The structure other than the reinforcing member 30 may be the same as that of the cooling devices 10 of the respective modes described in Figures 1 to 6 .

[0084] In this example, the inner side surface 34 of the reinforcing member 30 is arranged at a position closer to the inside (in the direction closer to the center of the coolant flow portion 92 in the xy plane) than the side wall 63. That is, the reinforcing member 30 may project like an eave from the side wall 63 toward the opening 42 in a plan view. According to such a structure, the side wall 63 can be more reliably supported by the reinforcing member 30. For example, even if there are deviations in the size or position of the reinforcing member 30, the side wall 63 can be supported. Therefore, deformation of the side wall 63 in the z-axis direction can be prevented, and the side wall 63 can be protected. In Figure 7 , the length of the reinforcing member 30 projecting more than the side wall 63 in the xy plane is set as L.

[0085] Figure 8 FIG. is a plan view showing an arrangement example of the inner side surface 34 of the reinforcing member 30. In Figure 8 , the housing portion 40 in the vicinity of the fastening portion 85 is shown enlarged. L1 is the length of the reinforcing member 30 projecting into the interior of the coolant flow portion 92 in the region facing the opening 42, and L2 is the length of the reinforcing member 30 projecting into the interior of the coolant flow portion 92 in the region facing the cooling fins 94. L1 may be larger than L2.

[0086] The region opposite to the opening 42 may refer to the region opposite to the opening 42 in a direction parallel to either the x-axis or the y-axis. The region opposite to the cooling fin 94 may refer to the region opposite to the cooling fin 94 in a direction parallel to either the x-axis or the y-axis and is a region not opposite to the opening 42.

[0087] The length L1 can be the protruding length of the reinforcing member 30 opposite to the center of the opening 42 in the xy-plane in a direction parallel to either the x-axis or the y-axis. The length L2 can be the protruding length of the reinforcing member 30 opposite to the center of the cooling fin 94 in the xy-plane in a direction parallel to either the x-axis or the y-axis.

[0088] By increasing the protruding length L1 of the reinforcing member 30 opposite to the opening 42, the region where stress is likely to occur, such as when connecting the pipe 90, can be made stronger. Additionally, by reducing the protruding length L2 of the reinforcing member 30 opposite to the cooling fin 94, the interference between the cooling fin 94 and the reinforcing member 30 can be prevented. The length L2 can also be 0.

[0089] Figure 9 It is a diagram showing another example of the shapes of the housing portion 40 and the reinforcing member 30. For the housing portion 40 of this example, at the corner 19-1 of the bottom plate 64 where the opening 42 is disposed, the side wall 63 extends in a direction (in Figure 9 it is the direction with -x and -y components) away from the center of the coolant flow portion 92 when viewed from above. The extended side wall 63-1 is disposed at a position outside the extension line 65 obtained by extending the other side walls 63 when viewed from above. At least a part of the opening 42 can be disposed to be surrounded by the side wall 63-1. The region of at least a part of the opening 42 can be disposed at a position outside the extension line 65. The shape of the side wall 63-1 when viewed from above can have an arc. That is, the side wall 63-1 can have a curved surface portion.

[0090] When viewed from above, the center position of the arc of the side wall 63-1 can coincide with the center position of the opening 42. By providing the side wall 63-1, the coolant introduced from the opening 42 can be directed towards the cooling fin 94.

[0091] The frame portion 62 can be bent along the side wall 63-1 towards the outside of the coolant flow portion 92. The width W2 at the portion where the side wall 63-1 is provided of the frame portion 62 can be smaller than the width W1 at the portion where the side wall 63 other than the side wall 63-1 is provided of the frame portion 62.

[0092] The reinforcing member 30 may have the same shape as the frame portion 62 of the housing portion 40 when viewed from above. The inner side surface 34 of the reinforcing member 30 and the inner side surface 13 of the frame portion 62 may coincide when viewed from above. When viewed from above, the distance r2 from the center of the opening portion 42 to the inner side surface 34 of the reinforcing member 30 may be the same as the distance r1 from the center of the opening portion 42 to the side wall 63-1. Alternatively, the distance r2 may be smaller than the distance r1. That is, as shown by the dashed line in the figure, the reinforcing member 30 may also protrude like an eave from the side wall 63-1 toward the opening portion 42. By making the distance r2 smaller than the distance r1, the strength of the region where stress is likely to occur, such as when connecting the connecting pipe 90, can be improved.

[0093] Figure 9 The structure shown can be applied to Figures 1 to 8 each of the modes described in. Further, in Figure 9 a vicinity of one corner portion 19-1 is shown, but the same structure may also be provided in the vicinity of the other corner portions 19-1. Further, the top plate 20 may also have the same shape as the Figure 9 housing portion 40 shown when viewed from above.

[0094] Figure 10 FIG. is a schematic diagram of a vehicle 200 showing an embodiment of the present invention. The vehicle 200 is a vehicle that uses electricity to generate at least a part of the driving force. As an example, the vehicle 200 is an electric vehicle that uses an electric drive device such as a motor to generate all of the driving force, or a hybrid vehicle that uses an electric drive device such as a motor together with an internal combustion engine driven by a fuel such as gasoline.

[0095] The vehicle 200 includes a control device 210 (external device) that controls an electric drive device such as a motor. A semiconductor module 100 is provided in the control device 210. The semiconductor module 100 can control the power supplied to the electric drive device.

[0096] Figure 11 FIG. is a main circuit diagram of a semiconductor module 100 according to an embodiment of the present invention. The semiconductor module 100 may be a part of an in-vehicle unit that drives a motor of a vehicle. The semiconductor module 100 can function as a three-phase AC inverter circuit having output terminals U, V, and W.

[0097] The semiconductor chips 78-1, 78-2, and 78-3 can form the lower arm in the semiconductor module 100, and multiple semiconductor chips 78-4, 78-5, and 78-6 can form the upper arm in the semiconductor module 100. A group of semiconductor chips 78-1 and 78-4 can form a bridge arm. A group of semiconductor chips 78-2 and 78-5, and a group of semiconductor chips 78-3 and 78-6 can also form bridge arms in the same way. In the semiconductor chip 78-1, the emitter electrode can be electrically connected to the input terminal N1, and the collector electrode can be electrically connected to the output terminal U. In the semiconductor chip 78-4, the emitter electrode can be electrically connected to the output terminal U, and the collector electrode can be electrically connected to the input terminal P1. Similarly, in the semiconductor chips 78-2 and 78-3, the emitter electrodes can be electrically connected to the input terminals N2 and N3 respectively, and the collector electrodes can be electrically connected to the output terminals V and W respectively. In addition, in the semiconductor chips 78-5 and 78-6, the emitter electrodes can be electrically connected to the output terminals V and W respectively, and the collector electrodes can be electrically connected to the input terminals P2 and P3 respectively.

[0098] Each of the semiconductor chips 78-1 to 78-6 can be alternately switched according to the signal input to the control electrode pads of the semiconductor chip 78. In this example, each semiconductor chip 78 can generate heat when switched. The input terminals P1, P2, and P3 can be connected to the positive pole of an external power supply, the input terminals N1, N2, and N3 can be connected to the negative pole, and the output terminals U, V, and W can be connected to a load. The input terminals P1, P2, and P3 can be electrically connected to each other, and in addition, the other input terminals N1, N2, and N3 can also be electrically connected to each other.

[0099] In the semiconductor module 100, the multiple semiconductor chips 78-1 to 78-6 can each be an RC-IGBT (reverse conducting IGBT) semiconductor chip. In the RC-IGBT semiconductor chip, the IGBT and the freewheeling diode (FWD) can be integrally formed, and the IGBT and the FWD can be connected in reverse parallel. The multiple semiconductor chips 78-1 to 78-6 can each include a combination of transistors and diodes such as MOSFETs and / or IGBTs. The chip substrates of the transistors and diodes can be silicon substrates, silicon carbide substrates, or gallium nitride substrates.

[0100] As described above, the present invention has been illustrated by the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be added to the above embodiments. These forms with added changes or improvements are also included in the technical scope of the present invention.

[0101] It should be noted that, regarding the execution order of each process such as actions, sequences, steps, and stages in the devices, systems, programs, and methods shown in the specification and the drawings, as long as there is no specific explicit indication of "before", "prior to", etc., and the output of the previous process is not used for the subsequent process, it can be implemented in any order. Regarding the action flow in the specification and the drawings, even if descriptions such as "first", "then", etc. are used for convenience, it does not mean that it must be implemented in that order.

Claims

1. A cooling device, characterized in that, A cooling device for a semiconductor module including a semiconductor chip The cooling device includes: A top plate having a lower surface; A housing portion having a coolant flow portion, an outer edge portion surrounding the coolant flow portion, a bottom plate, and side walls. The side walls connect the inner side surface of the outer edge portion facing the coolant flow portion to the outer peripheral portion of the bottom plate, thereby partitioning the coolant flow portion between the bottom plate and the lower surface of the top plate. The coolant flow portion is disposed on the lower surface side of the top plate, and the housing portion is disposed in direct or indirect contact with the lower surface of the top plate at the outer edge portion; And Cooling fins disposed in the coolant flow portion, The top plate and the housing portion have fastening portions for fastening the top plate and the housing portion to an external device, and the top plate and the outer edge portion are overlapped and disposed at the fastening portion, The cooling device further includes a reinforcing member at the fastening portion, and the reinforcing member is brazed between the top plate and the outer edge portion, The reinforcing member is formed of a material having an elastic limit stress higher than the elastic limit stresses of the top plate and the housing portion, The reinforcing member is formed of an aluminum alloy having an elastic limit stress of 50 MPa or more.

2. The cooling device according to claim 1, wherein The fastening portion protrudes outward from the outer periphery of the top plate in the circumferential direction.

3. The cooling device according to claim 2, wherein The top plate has two pairs of opposite sides and four corners in a plan view, The fastening portion is provided to protrude outward more than the outer periphery of the top plate at at least one of the corners, The bottom plate of the housing portion has four corners, and an opening portion is provided at at least one of the corners of the bottom plate. The opening portion connects the coolant flow portion to the outside, The corner of the top plate where the fastening portion is provided and the corner of the bottom plate where the opening portion is provided are disposed at opposite positions.

4. The cooling device according to claim 3, wherein The top plate has a pair of opposite long sides and a pair of opposite short sides in a plan view, The fastening portion is provided at two corners, a first corner where the opening portion is provided and a second corner where the opening portion is not provided, The first fastening portion at the first corner is provided to protrude in a direction parallel to the long side, and the second fastening portion at the second corner is provided to protrude in a direction different from the first fastening portion.

5. The cooling device according to any one of claims 1 to 4, wherein A plurality of the reinforcing members are stacked at the fastening portion.

6. The cooling device according to any one of claims 1 to 4, wherein The top plate has a side surface along the outer periphery, The reinforcing member has an inner side surface facing the coolant flow portion and an outer side surface opposite to the inner side surface, The outer side surface of the reinforcing member is disposed flush with the side surface of the top plate.

7. The cooling device according to claim 1, wherein The brazing material for brazing is an aluminum alloy having an elastic limit stress in the range of 35 to 65 MPa at room temperature.

8. The cooling device according to any one of claims 1 to 4, characterized in that the thickness at a position of the housing portion opposite to the center of the lower surface of the top plate is the same as the thickness at the fastening portion of the housing portion.

9. The cooling device according to any one of claims 1 to 4, characterized in that at the fastening portion, the reinforcing member, the top plate and the housing portion have the same thickness, the outer edge portion at least includes a frame portion, the frame portion and the side wall have the same thickness.

10. A cooling device, characterized in that, It is a cooling device for a semiconductor module including a semiconductor chip, the cooling device includes: a top plate having an upper surface and a lower surface opposite to the upper surface, and capable of mounting the semiconductor chip on the upper surface; a reinforcing member brazed along the outer periphery of the lower surface of the top plate; a housing portion including a coolant flow portion disposed on the lower surface side of the top plate; cooling fins disposed in the coolant flow portion; and a fastening portion, the housing portion has a frame portion, a bottom plate and side walls, the frame portion has an upper surface and a lower surface opposite to the upper surface, and the upper surface is disposed in direct or indirect contact with the lower surface of the top plate, the bottom plate has corners and an opening provided at the corners, and the coolant flow portion is disposed between the bottom plate and the lower surface of the top plate, the side walls connect the inner side surface of the frame portion facing the coolant flow portion to the periphery of the bottom plate, and define the coolant flow portion between the top plate and the bottom plate, the fastening portion is provided to protrude outward from the outer periphery of the top plate to the side opposite to the opening and the corners of the bottom plate. At the fastening portion, the frame portion, the reinforcing member and the top plate are stacked in sequence, and the fastening portion has a through hole penetrating the frame portion, the reinforcing member and the top plate, the reinforcing member is formed of an aluminum alloy having an elastic limit stress higher than the elastic limit stresses of the top plate and the housing portion and having an elastic limit stress of 50 MPa or more.

11. The cooling device according to claim 10, characterized in that a pipe is connected to the opening of the bottom plate of the housing portion, and the pipe protrudes to the side opposite to the cooling fins.

12. A semiconductor module, characterized in that, It includes: the cooling device according to any one of claims 1 to 11; and a semiconductor device disposed above the top plate.

13. A vehicle, characterized in that it includes the semiconductor module according to claim 12.

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