Semiconductor module and vehicle

Abstract

In a situation where the temperature repeatedly changes due to the outside environment and heat generation of the semiconductor element, a large stress and plastic strain are generated at the fixing agent that fixes the semiconductor element to the cooler. The semiconductor module of the present application includes a semiconductor device having a semiconductor chip and a circuit substrate on which the semiconductor chip is mounted, and a cooling device including a top plate on which the semiconductor device is mounted, a side wall connected to the top plate, a bottom plate connected to the side wall and opposite to the top plate, and a refrigerant flow passage portion for allowing a refrigerant to flow, which is substantially rectangular with long and short sides in a cross section parallel to a main surface of the top plate, and is defined by the top plate, the side wall, and the bottom plate. The circuit substrate is a substantially rectangular laminated substrate including, in order, an insulating plate having an upper surface and a lower surface, a circuit layer provided on the upper surface, and a metal layer provided on the lower surface. In a plan view, at least one corner portion of the metal layer at least partially overlaps with an inclined portion of the side wall.

Description

Technical Field

[0001] This invention relates to semiconductor modules and vehicles. Background Technology

[0002] Previously, semiconductor modules containing multiple semiconductor elements, such as power semiconductor chips, were known to be equipped with a cooling device including cooling fins (see, for example, Patent Documents 1-4).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-018904

[0006] Patent Document 2: Japanese Patent Application Publication No. 2012-064609

[0007] Patent Document 3: Japanese Patent Application Publication No. 2019-080016

[0008] Patent Document 4: WO2015 / 079643 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] In the aforementioned semiconductor module, due to the significant difference between the linear expansion coefficient of the circuit board on which the semiconductor components are mounted and the linear expansion coefficient of the cooler, a large stress and plastic strain are generated at the fixation point where the circuit board is fixed to the cooler under conditions of repeated temperature changes caused by external environment and self-heating.

[0011] Technical solutions adopted to solve technical problems

[0012] To address the aforementioned problems, a first aspect of the present invention provides a semiconductor module including a semiconductor device and a cooling device. The semiconductor device may have a semiconductor chip and a circuit board on which the semiconductor chip is mounted. The cooling device may include a top plate on which the semiconductor device is mounted. The cooling device may include a sidewall connected to the top plate. The cooling device may include a bottom plate connected to the sidewall and opposite to the top plate. The cooling device may include a refrigerant flow section defined by the top plate, sidewall, and bottom plate, having a generally rectangular cross-section with a long side and a short side parallel to the main surface of the top plate, for the flow of refrigerant. The circuit board may be a generally rectangular laminated substrate, sequentially including an insulating plate having an upper surface and a lower surface, a circuit layer disposed on the upper surface, and a metal layer disposed on the lower surface. In plan view, the sidewall may include an inclined portion at at least one corner, the inclined portion being inclined inwards at angles relative to both the long and short sides. In plan view, at least one corner of the metal layer may at least partially overlap with the inclined portion.

[0013] Viewed from above, the outline of at least one corner of the metal layer may be located between the inside and outside of the inclined portion.

[0014] Viewed from above, the portion of the metal layer other than the corners may not overlap with the sidewalls.

[0015] The sidewall may include two inclined portions at at least two corners. In top view, the two corners of the metal layer may at least partially overlap with the two inclined portions.

[0016] In the direction of the short side, the length of one side of the inner sidewall can be shorter than the length of one side of the metal layer of the circuit board.

[0017] The insulating board may contain ceramic. The metal layer can be fixed to the top plate with solder.

[0018] The top plate and side walls can be formed as one unit.

[0019] The top plate and side walls can be formed as one piece.

[0020] The top and side walls can be fixed with a fixative.

[0021] In a plane orthogonal to the viewpoint, the thickness of the top plate section can be thicker on the outer side of the sidewall than on the inner side.

[0022] In a second aspect of the present invention, a semiconductor module including a semiconductor device and a cooling device is provided. The semiconductor device may have a semiconductor chip. The semiconductor device may have a circuit board. The circuit board may include an insulating plate having an upper surface and a lower surface, a circuit layer disposed on the upper surface, and a metal layer disposed on the lower surface, with the semiconductor chip mounted on the circuit layer. The cooling device may include a top plate on which the semiconductor device is mounted. The cooling device may include a sidewall connected to the top plate. The cooling device may include a bottom plate connected to the sidewall and opposite to the top plate. The cooling device may include a refrigerant flow section defined by the top plate, sidewall, and bottom plate for allowing refrigerant to flow. The sidewall may include a set of first sidewall elements extending in one direction and opposite to each other. The sidewall may also include a set of first sidewall elements extending in another direction and opposite to each other. The sidewall may include an inclined portion connecting the ends of the first sidewall elements and the ends of the second sidewall elements. In plan view, the metal layer may be generally rectangular, with the corners of the metal layer partially overlapping the inclined portion.

[0023] Viewed from above, one direction can be roughly orthogonal to another, and the extension direction of the inclined part intersects one direction at an angle of more than 30 degrees and less than 60 degrees.

[0024] The sidewall may contain four inclined sections. In top view, the length of the second sidewall element may be shorter than the length of the first sidewall element, and the length of the second sidewall element may be shorter than the length of one edge of the metal layer.

[0025] The sidewall may contain two inclined sections.

[0026] In the third aspect of the present invention, a vehicle is provided that includes one of the semiconductor modules involved in the first aspect and the semiconductor modules involved in the second aspect.

[0027] Furthermore, the above summary of the invention is not an enumeration of all essential features of the invention. In addition, sub-combinations of these feature groups can also constitute an invention. Attached Figure Description

[0028] Figure 1 This is a schematic perspective view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention.

[0029] Figure 2 This is a schematic perspective view showing an example of a cooling device 10 for a semiconductor module 100 according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic cross-sectional view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention.

[0031] Figure 4 yes Figure 3 A magnified view of the area [A] shown by the dashed line.

[0032] Figure 5 This is a diagram illustrating an example of the arrangement of the fin region 95 of the cooling device 10, the arrangement of the metal layer 85 of the semiconductor device 70, the shape of the cooling needle fins 94, and the flow direction of the refrigerant in a semiconductor module 100 according to an embodiment of the present invention.

[0033] Figure 6 This is a diagram illustrating the dimensions of the metal layer 85 of the semiconductor device 70, the dimensions of the sidewall 36 of the cooling device 10, and the configuration relationship of the metal layer 85 relative to the sidewall 36 in a semiconductor module 100 according to an embodiment of the present invention.

[0034] Figure 7 This is a diagram illustrating a modified example of metal layer 85, namely metal layer 86, in a semiconductor module 100 according to an embodiment of the present invention.

[0035] Figure 8 This is a diagram illustrating the first comparative example.

[0036] Figure 9This is a diagram illustrating the second comparative example.

[0037] Figure 10 This is a diagram illustrating a modified example of the sidewall 36, namely the sidewall 38, in a semiconductor module 100 according to an embodiment of the present invention.

[0038] Figure 11 This is a diagram illustrating a modified example of a sidewall 39 (as a sidewall 36) and a modified example of a metal layer 86 (as a metal layer 85) in a semiconductor module 100 according to an embodiment of the present invention.

[0039] Figure 12 This is a diagram showing a modified example of the metal layer 87 in a semiconductor module 100 according to an embodiment of the present invention, which is a metal layer 85 of a semiconductor device 70.

[0040] Figure 13 This is a diagram showing a modified example of the metal layer 88 in a semiconductor module 100 according to an embodiment of the present invention, which is a metal layer 85 of a semiconductor device 70.

[0041] Figure 14 This is a diagram showing a modified example of the metal layer 89 in a semiconductor module 100 according to an embodiment of the present invention, which is a metal layer 85 of a semiconductor device 70.

[0042] Figure 15 This is a diagram showing a modified example of the metal layer 90 in a semiconductor module 100 according to an embodiment of the present invention, which is a metal layer 85 of a semiconductor device 70.

[0043] Figure 16 This is a diagram illustrating a schematic representation of a vehicle 200 according to one embodiment of the present invention.

[0044] Figure 17 This is a main circuit diagram of a semiconductor module 100 according to one embodiment of the present invention. Detailed Implementation

[0045] The present invention will now be described through embodiments thereof, but these embodiments do not limit the invention as defined in the patent claims. Furthermore, the combinations of features described in the embodiments are not necessarily all necessary technical means to solve the technical problems of the present invention.

[0046] Figure 1 This is a schematic perspective view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention. Figure 2 This is a schematic perspective view showing an example of the cooling device 10 of the semiconductor module 100. Additionally, Figure 3This is a schematic cross-sectional view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention. Figure 4 yes Figure 3 A magnified view of region A in the image. Additionally, Figure 5 This is a diagram illustrating an example of the arrangement of the fin region 95 of the cooling device 10, the arrangement of the metal layer 85 of the semiconductor device 70, the shape of the cooling needle fins 94, and the flow direction of the refrigerant in a semiconductor module 100 according to an embodiment of the present invention.

[0047] Figure 3 The diagram shows an imaginary cut in the xz plane. Figure 1 The semiconductor chip 78 of the U-phase unit 70U in the semiconductor module 100 shown, and Figure 2 The state of both the outlet 42 of the cooling device 10 shown. Additionally, Figure 4 In the diagram, T1 shows the thickness of the fastening portion 21 of the top plate 20 in the z-axis direction, T2 shows the thickness of the top plate 20 in the z-axis direction in the fin region 95, T3 shows the thickness of the sidewall 36 in the x-axis direction, and T4 shows the thickness of the bottom plate 64 in the z-axis direction. Additionally, Figure 5 In the middle, it is shown by dashed lines. Figure 1 The metal layer 85 of each of the U-phase unit 70U, V-phase unit 70V and W-phase unit 70W shown.

[0048] Semiconductor module 100 includes semiconductor device 70 and cooling device 10. In this example, semiconductor device 70 is mounted on cooling device 10. In this embodiment, the surface of cooling device 10 on which semiconductor device 70 is mounted is designated as the xy-plane, and the axis perpendicular to the xy-plane is designated as the z-axis. The xyz-axis forms a right-handed system. In this embodiment, the direction from cooling device 10 toward semiconductor device 70 in the z-axis direction is called "up," and the opposite direction is called "down," but the "up" and "down" directions are not limited to the direction of gravity. Furthermore, in this embodiment, among the surfaces of each component, the upper surface is called the upper surface, the lower surface is called the lower surface, and the surface between the upper and lower surfaces is called the side surface. In this embodiment, "top view" means viewing semiconductor module 100 from the positive z-axis direction.

[0049] Semiconductor device 70 includes a semiconductor chip 78 and a circuit board 76 on which the semiconductor chip 78 is mounted. The semiconductor device 70 of this example may include three circuit boards 76, each circuit board 76 may mount two semiconductor chips 78. Figure 1As shown, the semiconductor device 70 in this example is a power semiconductor device, which may have a U-phase unit 70U including a circuit board 76, semiconductor chips 78-1 and 78-4, a V-phase unit 70V including a circuit board 76, semiconductor chips 78-2 and 78-5, and a W-phase unit 70W including a circuit board 76, semiconductor chips 78-3 and 78-6. The semiconductor module 100 in this example can function as a device constituting a three-phase AC inverter. In addition, each semiconductor chip 78 of the U-phase unit 70U, V-phase unit 70V, and W-phase unit 70W becomes a heat source that generates heat when the semiconductor module 100 is in operation.

[0050] Semiconductor chip 78 is a vertically oriented semiconductor device with an upper surface electrode and a lower surface electrode. As an example, semiconductor chip 78 includes components such as an insulated-gate bipolar transistor (IGBT), a MOSFET, and a current-driven diode (FWD) formed on a semiconductor substrate such as silicon. In semiconductor chip 78, the IGBT and FWD can be reverse-biased IGBTs (RC-IGBTs) formed on a single semiconductor substrate. In an RC-IGBT, the IGBT and FWD can be connected in reverse parallel.

[0051] The lower surface electrode of the semiconductor chip 78 is connected to the upper surface of the circuit substrate 76. In this example, the semiconductor chip 78 can be fixed to the upper surface of the circuit substrate 76 by solder 79. The upper surface electrode of the semiconductor chip 78 can be an emitter, source, or anode electrode, and the lower surface electrode can be a collector, drain, or cathode electrode. The semiconductor substrate in the semiconductor chip 78 can be silicon carbide (SiC) or gallium nitride (GaN).

[0052] The semiconductor chip 78, which includes switching elements such as IGBTs and MOSFETs, has control electrodes. The semiconductor chip 100 may have control terminals connected to the control electrodes of the semiconductor chip 78. The switching elements can be controlled by an external control circuit via the control terminals.

[0053] like Figure 3 and Figure 4As shown, the circuit board 76 is a generally rectangular laminated substrate, comprising, in sequence, an insulating plate 81 having an upper surface and a lower surface, a circuit layer 83 disposed on the upper surface of the insulating plate 81, and a metal layer 85 disposed on the lower surface of the insulating plate 81. The circuit board 76 has an upper surface and a lower surface, with the lower surface disposed on the upper surface of the cooling device 10. The circuit board 76 is fixed to the upper surface of the cooling device 10 via solder 79 through the metal layer 85. Additionally, as an example, two semiconductor chips 78 are fixed to the upper surface of the circuit board 76 via the circuit layer 83. Furthermore, in this specification, "generally rectangular" can mean generally quadrilateral or generally rectangular, and at least one corner can be a chamfered shape or a smooth shape. For example, a generally rectangular shape can include an octagon, a 12-sided shape, a 16-sided shape, etc., obtained by chamfering each of the four corners.

[0054] The circuit board 76 can be, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazing) substrate. The insulating plate 81 can be formed using ceramic materials such as alumina (Al2O3), aluminum nitride (AlN), or silicon nitride (Si3N4). The circuit layer 83 and the metal layer 85 can be substrates containing conductive materials such as copper or copper alloys. The circuit layer 83 is fixed to the upper surface of the insulating plate 81 by solder or brazing filler metal. The upper surface of the circuit layer 83 is electrically or mechanically connected to the semiconductor chip 78 via solder or the like, i.e., directly connected in a circuit manner. In addition, the circuit layer 83 can be electrically connected to other conductive components via wires or the like.

[0055] The cooling device 10 has a chassis 40 and a base plate 64. The chassis 40 includes a top plate 20 on which a semiconductor device 70 is mounted, a side wall 36 connected to the top plate 20, and a plurality of cooling needle-shaped fins 94 connected to the top plate 20.

[0056] The top plate 20 is a plate-shaped component with a main surface extending into the xy-plane. In this example, the top plate 20, viewed from above, is approximately rectangular with a long side and a short side. Furthermore, in this example, the short side of the top plate 20 is parallel to the x-axis, and its long side is parallel to the y-axis. The top plate 20 includes a fastening part 21 for fastening to an external device on which the semiconductor module 100 is mounted. In view from above, the fastening part 21 is located further outward than the sidewall 36 connected to the top plate 20, and has through holes 80 for inserting screws or the like into which the external device can be inserted. In this example, the fastening part 21 has through holes 80 at each of the four corners of the approximately rectangular top plate 20, for a total of four through holes 80.

[0057] like Figure 3As shown, the top plate 20 has an upper surface (surface) 22 and a lower surface (back surface) 24 parallel to the xy plane. As an example, the top plate 20 is formed of metal; more specifically, it is formed of a metal containing an aluminum alloy. A plating layer such as nickel can be formed on the surface of the top plate 20. A semiconductor device 70 is mounted on the upper surface 22 of the top plate 20. In this case, the circuit board 76 of the semiconductor device 70 can be directly fixed to the upper surface 22 of the top plate 20 using solder 79. The top plate 20 transfers heat generated in each semiconductor chip 78. The top plate 20, circuit board 76, and semiconductor chips 78 are arranged sequentially toward the positive z-axis. Thermal connections can be made between the top plate 20 and the circuit board 76, i.e., between the circuit board 76 and the semiconductor chips 78. In this example, the respective components are fixed together by solder 79, and the components are thermally connected via this solder 79.

[0058] Here, as Figure 3 As shown, the semiconductor device 70 described above can additionally include a housing portion 72. The housing portion 72 is, for example, a frame formed of an insulating material such as thermosetting resin or UV-curable resin, and can be configured to surround the area where the circuit board 76 and the like are disposed on the upper surface 22 of the top plate 20. The housing portion 72 can be bonded to the upper surface 22 of the top plate 20. The housing portion 72 has an internal space capable of housing the semiconductor chip 78, the circuit board 76, and other circuit elements. The internal space of the housing portion 72 can accommodate various structural elements, including the circuit board 76 and the semiconductor chip 78 of the semiconductor device 70. The internal space of the housing portion 72 can be filled with a sealing portion 74 to seal the semiconductor chip 78, the circuit board 76, and other circuit elements. The sealing portion 74 is, for example, an insulating member containing a resin such as silicone gel or epoxy resin. Furthermore, Figure 1 For the purpose of simplification, the illustrations of the storage part 72 and the sealing part 74 have been omitted.

[0059] The sidewall 36 has a generally fixed thickness and forms the side of the cooling device 10. In this example, the sidewall 36 has a generally rectangular outline with a long side and a short side in the xy plane. The sidewall 36 forms the side of the cooling device 10, so that in a top view, the short side of the outline of the sidewall 36 is parallel to the x-axis and the long side is parallel to the y-axis. In addition, in a top view, the sidewall 36 in this example is located closer to the inside than the fastening part 21 of the top plate 20, and extends from the top plate 20 along the negative z-axis. Furthermore, the term "outline" can refer to the lines that form the shape of an object.

[0060] The sidewall 36 may include a set of sidewall elements 36L extending along the y-axis and opposite to each other, and a set of sidewall elements 36S extending along the x-axis and opposite to each other. The thickness of the sidewall 36 may be, for example, more than 1 mm and less than 3 mm. The extending directions of the sidewall elements 36L and 36S are approximately orthogonal to each other in the range of 85 to 95 degrees when viewed from above, and preferably intersect each other at 90 degrees. The length of the sidewall element 36S may be shorter than the length of the sidewall element 36L. The sidewall element 36L may be a straight line or may include a curve when viewed from above.

[0061] Viewed from above, the sidewall 36 includes an inclined portion 37 at at least one corner, the inclined portion 37 being inclined inward at angles relative to the y-axis and x-axis directions, respectively. For example, the sidewall 36 may include an inclined portion 37 connecting the end of the sidewall element 36S to the end of the sidewall element 36L. Figure 5 In the diagram, the inclined portion 37 is shown as a mesh-like area. The same applies in the following figures.

[0062] The inclined portion 37 can be configured to connect the end of the sidewall element 36L to the end of the sidewall element 36S. In top view, the extending direction and y-axis direction of the inclined portion 37 are as described later. Figure 6 As shown by the angle θ, for example, they can cross at an angle (angle) of 30 degrees or more and 60 degrees or less. Figure 6 The angle θ shown can preferably be between 40 and 50 degrees. The shape of the sidewall 36, when viewed from above, can be a polygon, such as an n-sided polygon (n is an integer greater than or equal to 5), preferably a hexagon or an octagon.

[0063] Viewed from above, the sidewall 36 may include two inclined portions 37 at at least two corners. For example... Figure 5 As shown, the sidewall 36 in this example includes inclined portions 37 at each of its four corners. Furthermore, in top view, the term "corner" of the sidewall 36 can refer to the region where the shorter side extending along the x-axis of the sidewall 36 intersects the longer side extending along the y-axis. Additionally, in top view, the term "inner side" of the sidewall 36 can refer to one side of the region enclosed by the sidewall 36, which has a generally rectangular outline.

[0064] Figure 5 The diagram shows the centerline CL, which extends from the center of sidewall 36 in the x-axis direction along the y-axis direction. (See diagram for example.) Figure 5 As shown, in top view, the metal layers 85 of each circuit board 76, i.e., each circuit board 76, can be offset relative to the center line CL along the x-axis direction. In this case, in the x-axis direction, the length of one side of the inner sidewall 36 can be the same as the length of one side of the metal layer 85 of the circuit board 76, or it can be longer than the length of one side of the metal layer 85. Figure 5As shown, in this example, the length of the inner side of the two sides of the sidewall 36 extending along the x-axis can be the same as the length of the two sides of the metal layer 85 of each circuit board 76 extending along the x-axis. For example, the length of the sidewall element 36S can be the same as the length of one side of the metal layer 85 in the x-axis direction.

[0065] Instead, for example, if the centers of each circuit board 76 in the x-axis direction are arranged on the centerline CL, the length of one side of the inner side of the sidewall 36 in the x-axis direction can be shorter than the length of one side of the metal layer 85 of the circuit board 76. For example, a variation of the metal layer 85, namely the metal layer 86, in a semiconductor module 100 according to an embodiment of the present invention will be described. Figure 7 As shown, the length of the sidewall element 36S can be shorter than the length of one side of the metal layer 86 in the x-axis direction. Figure 7 The aspect ratio of metal layer 86 shown is different from that of metal layer 85, and the length of its side in the x-axis direction is relatively longer. Additionally, Figure 7 Only the metal layers 85 of the sidewall 36, U-phase unit 70U, V-phase unit 70V, and W-phase unit 70W in semiconductor module 100 are shown. The following will describe... Figure 6 , Figures 8-11 The same applies to China.

[0066] From a top view, at least one corner of the metal layer 85 of the circuit board 76 at least partially overlaps with the inclined portion 37 of the sidewall 36. For example, from a top view, the metal layer 85 is generally rectangular, and the corner of the metal layer 85 may partially overlap with the inclined portion 37. Figure 5 As shown in this example, in the U-phase unit 70U, V-phase unit 70V and W-phase unit 70W, the metal layer 85 of the circuit board 76 of each of the U-phase unit 70U and W-phase unit 70W located at both ends of the y-axis direction may overlap with the inclined portion 37 of the sidewall 36.

[0067] In this example, only one corner of the metal layer 85 of the circuit board 76 of each of the U-phase unit 70U and the W-phase unit 70W may overlap with the inclined portion 37 of the sidewall 36. More specifically, one corner of the metal layer 85 of the U-phase unit 70U, located on the negative y-axis side and the positive x-axis side, may overlap with the inclined portion 37 of the sidewall 36, located on the negative y-axis side and the positive x-axis side. Similarly, one corner of the metal layer 85 of the W-phase unit 70W, located on the positive y-axis side and the positive x-axis side, may overlap with the inclined portion 37 of the sidewall 36, located on the positive y-axis side and the positive x-axis side.

[0068] Instead, preferably, from a top view, the two corners of the metal layer 85 of the circuit board 76 can at least partially overlap with the two inclined portions 37 of the sidewall 36. More specifically, the two corners of the metal layer 85 of the U-phase unit 70U located on the negative y-axis side can each partially overlap with the two inclined portions 37 of the sidewall 36 located on the negative y-axis side. Similarly, the two corners of the metal layer 85 of the W-phase unit 70W located on the positive y-axis side can each partially overlap with the two inclined portions 37 of the sidewall 36 located on the positive y-axis side.

[0069] The metal layer 85, viewed from above, is approximately rectangular as described above, and may have a set of sides extending along the x-axis and a set of sides extending along the y-axis. The metal layer 85 may include multiple corners formed by chamfering at its corners.

[0070] Viewed from above, the outline of at least one corner of the metal layer 85 of the circuit board 76 may be located between the inner and outer sides of the inclined portion 37 of the sidewall 36. For example... Figure 5 As shown, in this example, from a top view, the two corners of the metal layer 85 of the U-phase unit 70U, located on the negative y-axis side, can be respectively located between the inner and outer sides of the two inclined portions 37 on the negative y-axis side of the sidewall 36. Similarly, the two corners of the metal layer 85 of the W-phase unit 70W, located on the positive y-axis side, can be respectively located between the inner and outer sides of the two inclined portions 37 on the positive y-axis side of the sidewall 36.

[0071] Furthermore, when viewed from above, the portion of the metal layer 85 of the circuit board 76, excluding the corners, may not overlap with the sidewall 36. For example... Figure 5 As shown, in this example, from a top view, the portion of the metal layer 85 of the U-phase unit 70U, excluding the two corners on the negative y-axis side, may not overlap with the sidewall 36. Similarly, the portion of the metal layer 85 of the W-phase unit 70W, excluding the two corners on the positive y-axis side, may not overlap with the sidewall 36.

[0072] At least one of the plurality of cooling needle-shaped fins 94 has a generally rhomboid cross-sectional shape in the xy plane. In the following description, one or more cooling needle-shaped fins 94 are sometimes simply referred to as cooling needle-shaped fins 94. The cooling needle-shaped fins 94 extend from the top plate 20 in the negative z-axis direction. In top view, the cooling needle-shaped fins 94 are located closer to the inner side than the sidewall 36 and are surrounded by the sidewall 36.

[0073] Figure 2In the cooling device 10, for simplification, the area where the cooling needle-shaped fins 94 are provided, i.e., the fin area 95, is shown as a dot instead of the cooling needle-shaped fins 94 in the figure. The fin area 95 can be rectangular in top view, with its short side parallel to the x-axis and its long side parallel to the y-axis.

[0074] In the chassis 40, the top plate 20, sidewall 36, and cooling needle-shaped fins 94 can be integrally formed. In this example, the top plate 20, sidewall 36, and cooling needle-shaped fins 94 can be formed as a single piece of continuous sheet metal. For example, relative to a continuous sheet metal, the top plate 20, sidewall 36, and cooling needle-shaped fins 94 can be integrally formed by punching using a metal die corresponding to the shape of the top plate 20, sidewall 36, and cooling needle-shaped fins 94. As another example, the top plate 20, sidewall 36, and cooling needle-shaped fins 94 can be integrally formed by any forging method such as cold forging at room temperature, warm forging, hot forging, or melt forging at high temperature, or by casting. The semiconductor module 100 of this embodiment integrates the top plate 20, the side wall 36, and the cooling needle fins 94 into one unit, thereby reducing the number of components compared to fixing separately formed components together.

[0075] The base plate 64 is a plate-shaped member. In this example, the base plate 64, viewed from above, is approximately rectangular with a long side and a short side. Furthermore, in this example, the short side of the base plate 64 is parallel to the x-axis, and its long side is parallel to the y-axis. The base plate 64 forms the bottom surface of the refrigerant flow section 92. The base plate 64 is connected to the side wall 36 and faces the top plate 20.

[0076] The refrigerant flow section 92, used for allowing refrigerant to flow, is defined by the top plate 20, side walls 36, and bottom plate 64. In other words, the side walls 36 are arranged in the xy plane to surround the refrigerant flow section 92, and the top plate 20 and bottom plate 64 are arranged opposite each other, sandwiching the refrigerant flow section 92 in the z-axis direction. Thus, the outline of the refrigerant flow section 92 in the xy plane is defined by the inner periphery of the side walls 36. Therefore, as... Figure 5 As shown, the refrigerant flow section 92 is a roughly rectangular cross-section with a long side 96 and a short side 93, parallel to the main surface of the top plate 20. Furthermore, in this example, the direction of the long side 96 is the y-axis direction, and the direction of the short side 93 is the x-axis direction.

[0077] In addition, the base plate 64 of this example has a through hole, i.e., an inlet 41, for introducing refrigerant into the refrigerant circulation section 92, and a through hole, i.e., an outlet 42, for discharging refrigerant from the refrigerant circulation section 92.

[0078] Inlet 41 and outlet 42 can be connected to pipes that communicate with an external refrigerant supply source. In other words, the cooling device 10 can be connected to an external refrigerant supply source through two pipes. Therefore, the cooling device 10 can draw refrigerant into one pipe through inlet 41, and after circulating inside the refrigerant circulation section 92, the refrigerant can be discharged to another pipe through outlet 42.

[0079] Inlet 41 and outlet 42 are located on one side of the cooling device 10 and the opposite side thereon in the x-axis direction, and on one side of the cooling device 10 and the opposite side thereon in the y-axis direction, respectively. That is, inlet 41 and outlet 42 are located at opposite ends of the refrigerant flow section 92, which has a generally rectangular shape, in the xy plane.

[0080] In this embodiment, the semiconductor module 100 allows heat generated from each semiconductor chip 78 arranged along the z-axis on the upper surface of the cooling device 10 to flow into the refrigerant circulation section 92 via the inlet 41 of the cooling device 10, diffuse throughout the refrigerant circulation section 92, and be efficiently cooled by the refrigerant flowing out via the outlet 42.

[0081] Refrigerant such as LLC and water flows through the aforementioned refrigerant circulation section 92. In the refrigerant circulation section 92, the refrigerant is introduced from an inlet 41 connected to one side of the short side 93 and discharged from an outlet 42 connected to the other side of the short side 93. The refrigerant contacts the lower surface 24 of the top plate 20 on which the circuit board 76 is mounted and the cooling needle-shaped fins 94 to cool the semiconductor device 70.

[0082] The refrigerant flow section 92 can be a sealed space that is in contact with the top plate 20, the side wall 36, and the bottom plate 64, respectively. The bottom plate 64 and the lower end of the side wall 36 in the negative z-axis direction are configured to be in direct or indirect close contact, and the refrigerant flow section 92 is sealed by the top plate 20, the side wall 36, and the bottom plate 64. Indirect close contact means that the lower end of the side wall 36 is in close contact with the bottom plate 64 through a sealing material, adhesive, brazing filler metal, or other component, i.e., a fixing agent 98, provided between the lower end of the side wall 36 and the bottom plate 64. Close contact means that the refrigerant inside the refrigerant flow section 92 does not leak out from the close contact portion. It is preferable to braze the lower end of the side wall 36 to the bottom plate 64. In addition, the chassis 40 and the bottom plate 64 are formed of metals with the same composition, and the brazing filler metal can be formed of a metal with a lower melting point than the chassis 40, such as a metal containing an aluminum alloy.

[0083] Cooling needle-shaped fins 94 are disposed in the refrigerant flow section 92, extending between the top plate 20 and the bottom plate 64. In this example, the cooling needle-shaped fins 94 extend along the z-axis in a manner substantially orthogonal to the principal surfaces of the top plate 20 and the bottom plate 64. Figure 4As shown, the cooling needle-shaped fins 94 of this example are arranged in a prescribed pattern on the xy plane, extending along the z-axis in a manner substantially orthogonal to the main surfaces of the top plate 20 and the bottom plate 64. Furthermore, the cooling needle-shaped fins 94 of this example have a generally rhomboid shape in cross-section of the xy plane, where the direction of the short side 93 of the refrigerant flow section 92 is longer than the direction of the long side 96. Of the pair of diagonals of the generally rhomboid, the diagonal parallel to the long side 96 is shorter than the diagonal parallel to the short side 93.

[0084] The cooling needle-shaped fin 94 has an upper end and a lower end opposite each other in the z-axis direction. The upper end is in thermal and mechanical contact with the lower surface 24 of the top plate 20 and extends from the lower surface 24 of the top plate 20 toward the refrigerant flow section 92. When the cooling needle-shaped fin 94 is integrally formed with the top plate 20, the upper end of the cooling needle-shaped fin 94 protrudes integrally from the lower surface 24 of the top plate 20 and extends from the lower surface 24 of the top plate 20 toward the refrigerant flow section 92. In this example, the lower end of the cooling needle-shaped fin 94 is fixed to the base plate 64 by a retainer 98. The lower end of the cooling needle-shaped fin 94 can be away from the base plate 64. If there is a gap between the cooling needle-shaped fin 94 and the base plate 64, even if the base plate 64 warps, it is difficult to generate stress between the cooling needle-shaped fin 94 and the base plate 64. The heat emitted by each semiconductor chip 78 moves to the refrigerant near the cooling needle-shaped fin 94. Thus, each semiconductor chip 78 is cooled.

[0085] like Figure 5 As shown by dashed lines, in the finned region 95 of the refrigerant flow section 92, the cooling needle-shaped fins 94 are arranged in greater numbers along the long side 96 than along the short side 93, forming a generally rectangular shape that is longer along the long side 96 than along the short side 93. The cooling needle-shaped fins 94 can be arranged in greater numbers per unit length along the long side 96 than along the short side 93 of the refrigerant flow section 92. As an example, the ratio of the number of cooling needle-shaped fins 94 arranged along the long side 96 of the refrigerant flow section 92 to the number of cooling needle-shaped fins 94 arranged along the short side 93 of the refrigerant flow section 92 in the finned region 95 can be within a specified range. The finned region 95 includes the area where the cooling needle-shaped fins 94 are provided and the flow paths between the cooling needle-shaped fins 94. Additionally, as shown in the diagram, in this example, the cooling needle-shaped fins 94 are arranged in a staggered pattern in fin region 95, but they can also be arranged in a square pattern instead. Furthermore, the spacing between adjacent cooling needle-shaped fins 94 can be narrower than the width of the cooling needle-shaped fins 94 themselves. Additionally, as... Figure 5 As shown, in this example, the metal layers 85 of the U-phase unit 70U, V-phase unit 70V and W-phase unit 70W are partially disposed on the outside of the fin region 95 when viewed from above.

[0086] Furthermore, in top view, the refrigerant flow section 92 includes a first refrigerant flow path 30-1 and a second refrigerant flow path 30-2 arranged to sandwich the fin region 95. The refrigerant flow path 30 refers to a space within the refrigerant flow section 92 with a height of at least a predetermined height (length in the z-axis direction). This predetermined height can be the distance between the top plate 20 and the bottom plate 64.

[0087] The first refrigerant flow path 30-1 is located on the side closer to the shorter side 93 than the fin region 95 and communicates with the inlet 41, extending along the longer side 96. The second refrigerant flow path 30-2 is located on the other side closer to the shorter side 93 than the fin region 95 and communicates with the outlet 42, extending along the longer side 96. The directions in which the first and second refrigerant flow paths 30-1 and 30-2 extend can also be referred to as the direction of the longer side 96 of the fin region 95. Furthermore, the first refrigerant flow path 30-1 is an example of a connected region, and the second refrigerant flow path 30-2 is an example of another connected region.

[0088] As described above, when multiple heat sources such as semiconductor chips 78 exist in the semiconductor device 70 of the semiconductor module 100 along the y-axis direction, if the main flow direction of the refrigerant flowing to the cooling device 10 is set to be parallel to the arrangement direction (y-axis direction) of the heat sources, each heat source cannot be cooled in the same way. Therefore, as in the semiconductor module 100 of this embodiment, it is possible to consider a configuration structure in which the main flow direction (positive x-axis direction) of the refrigerant flowing to the cooling device 10 is orthogonal to the arrangement direction (y-axis direction) of the multiple heat sources. More specifically, in the semiconductor module 100 of this embodiment, the cross-section (in the xy plane) of the refrigerant flow section 92 parallel to the main surface of the top plate 20 is a generally rectangular shape having a long side 96 and a short side 93. The refrigerant is introduced from an inlet 41 connected to one side in the direction of the short side 93 (x-axis direction) and discharged from an outlet 42 connected to the other side in the direction of the short side 93 (x-axis direction).

[0089] The cooling device 10 is equipped with cooling needle-shaped fins 94, which are designed to efficiently dissipate heat transferred from multiple heat sources to the refrigerant flowing within the refrigerant circulation section 92. In the cooling device 10, when using needle-shaped fins with a circular cross-section (in the xy plane) parallel to the main surface of the top plate 20, the heat dissipation efficiency is lower than when using needle-shaped fins with a polygonal cross-section (in the xy plane) parallel to the main surface of the top plate 20, because the surface area of ​​the needle-shaped fins in contact with the refrigerant is smaller. Furthermore, even when using needle-shaped fins with a polygonal cross-section (in the xy plane) parallel to the main surface of the top plate 20, if the cross-sectional shape has a square or regular hexagonal shape where the width of the refrigerant in the main flow direction in the xy plane is equal to the width in the direction orthogonal to that flow direction, or a rectangular cross-sectional shape where the width in the orthogonal direction is longer than the width in the flow direction, the area in the surface orthogonal to the flow direction increases, the refrigerant flow velocity loss increases, and the heat dissipation efficiency decreases. In contrast, according to the semiconductor module 100 of this embodiment, the cooling needle-shaped fins 94 disposed in the refrigerant flow section 92 have a roughly rhomboid shape in the xy plane cross-section where the direction of the short side 93 of the refrigerant flow section 92 is longer than the direction of the long side 96. Therefore, compared with the case of using the aforementioned polygonal needle-shaped fins, the area in the surface orthogonal to the main flow direction of the refrigerant is smaller, and the refrigerant flow velocity loss is smaller. In addition, the cooling needle-shaped fins 94 can be needle-shaped fins with a cross-section that is circular or polygonal and parallel to the main surface of the top plate 20.

[0090] Here, as Figure 4 As shown, the thickness of the cross-section of the top plate 20 in a plane orthogonal to the direction of view (xz plane and yz plane) can be made thicker on the outer side of the sidewall 36 than on the inner side of the sidewall 36. In the cooling device 10 of this example, the thickness T1 of the fastening part 21 can be made thicker than the thickness T2 of the fin region 95 in the top plate 20. By making the thickness of the fin region 95 in the top plate 20 thinner, heat from the semiconductor device 70 disposed on the upper surface 22 of the top plate 20 can be efficiently moved to the refrigerant flowing in the refrigerant flow section 92. On the other hand, by increasing the strength of the fastening part 21, damage to the fastening part 21 due to the strong fastening force that can be applied when the semiconductor module 100 is firmly fastened with external devices and bolts can be suppressed.

[0091] Furthermore, the thickness T3 of the sidewall 36 can be made thicker than the thickness T2 of the fin region 95 in the top plate 20. By thinning the thickness of the fin region 95 in the top plate 20, cooling efficiency can be improved in the same way as described above. On the other hand, by increasing the strength of the sidewall 36 connected to the top plate 20, deformation such as bending caused by mechanical or thermal effects in the fin region 95 in the top plate 20 can be suppressed. As a result, the semiconductor module 100 can suppress the generation of large stresses and plastic strains at the solder 79 where the semiconductor device 70 is fixed to the top plate 20.

[0092] Furthermore, the thickness T4 of the base plate 64 can be at least thicker than the thickness T2 in the fin region 95 of the top plate 20 and the thickness T3 of the sidewall 36, and may even be thicker than the thickness T1 of the fastening portion 21 of the top plate 20. As described above, the inlet 41 and the outlet 42 are respectively formed on the base plate 64. By forming the inlet 41 and the outlet 42, which are through holes, on the thickest base plate 64, the strength of the cooling device 10 can be improved, and the processing of the cooling device 10 can be made easier. The fastening portion 21 can be integrally formed with the top plate 20 and the sidewall 36 by forging, or it can be formed by the flange portion of the sidewall 36 formed by stamping and the fastening of the top plate 20.

[0093] After conducting experiments that repeatedly varied the temperature of the semiconductor module due to external environmental changes and its own heat generation, it was determined from a top-down view that the solder between the metal layer on the lower surface of the insulating plate and the top plate of the cooling device exhibited the greatest stress and plastic strain at the inner side of the corner near the sidewall. This can be attributed to the tendency of the top plate of the cooling device to deform. On the other hand, deformation of the top plate of the cooling device could be locally suppressed at the location where the lower surface connects to the sidewall and where rigidity is relatively high.

[0094] The semiconductor module 100 according to this embodiment includes a cooling device 10 and a semiconductor device 70 having a circuit board 76 mounted on a top plate 20 of the cooling device 10. The circuit board 76 is a generally rectangular laminated substrate, which sequentially includes an insulating plate 81 having an upper surface and a lower surface, a circuit layer 83 disposed on the upper surface of the insulating plate 81, and a metal layer 85 disposed on the lower surface of the insulating plate 81. The metal layer 85 is fixed to the upper surface 22 of the top plate 20, for example, by solder 79. In addition, according to the cooling device 10 of the semiconductor module 100 of this embodiment, when viewed from above, the sidewall 36 includes an inclined portion 37 at at least one corner, and at least one corner of the metal layer 85 of the circuit board 76 at least partially overlaps with the inclined portion 37 of the sidewall 36.

[0095] In the semiconductor module 100, the semiconductor device 70 generates a maximum heat of approximately 170°C during use. Meanwhile, the refrigerant flowing through the refrigerant circulation section 92 of the cooling device 10 maintains a temperature of approximately room temperature to 70°C. Consequently, a temperature difference of over 100°C may sometimes occur between the semiconductor device 70 and the cooling device 10. Furthermore, this temperature difference can vary significantly depending on the ambient temperature of the semiconductor module 100. According to the semiconductor module 100 of this embodiment, including the above-described structure, even in cases where there is a significant difference between the coefficient of linear expansion of, for example, the ceramic insulating plate 81 and the coefficient of linear expansion of, for example, the aluminum alloy cooling device 10, under conditions of repeated temperature changes caused by external environment and self-heating, large stresses and plastic strains can be suppressed at the solder 79 between the metal layer 85 disposed on the lower surface of the insulating plate 81 and the top plate 20 of the cooling device 10, thereby improving thermal cycling reliability. Furthermore, according to the semiconductor module 100 of this embodiment, although it has a semiconductor device of the same size as that of this embodiment when viewed from above, the sidewall 36 of the cooling device 10 is offset inward compared to a semiconductor module in which the metal layer of the circuit board does not overlap with the sidewall, thereby sometimes enabling the cooling device 10 to be miniaturized.

[0096] Figure 6 This is a diagram illustrating the dimensions of the metal layer 85 of the semiconductor device 70, the dimensions of the sidewall 36 of the cooling device 10, and the configuration relationship of the metal layer 85 relative to the sidewall 36 in a semiconductor module 100 according to an embodiment of the present invention.

[0097] like Figure 6 As shown, the metal layer 85 of this embodiment, when viewed from above, has an octagon with a length of 30 mm in the x-axis direction, a length of 35 mm in the y-axis direction, and an interior angle of 135° at its corners. On the other hand, the sidewall 36 of this embodiment, when viewed from above, has an octagon with one inner side of the sidewall 36 having a length of 30 mm in the x-axis direction, a length of 60 mm in the x-axis direction, a length of 114 mm in the y-axis direction, and an exterior angle of the inclined portion 37 having an angle of 49° relative to the x-axis and 41° relative to the y-axis.

[0098] Figure 8 This is a diagram illustrating the first comparative example. Figure 9 This is a diagram illustrating the second comparative example. (See diagram below.) Figure 8 As shown, as a first comparative example of the semiconductor module 100 involved in this embodiment, although it has the same size and shape as the sidewall 36 and metal layer 85 of the semiconductor module 100 involved in this embodiment, in top view, a semiconductor module with sidewalls and metal layers that do not overlap with each other is provided. Furthermore, as... Figure 9As shown, as a second comparative example of the semiconductor module 100 involved in this embodiment, although it has the same size and shape as the sidewall 36 and metal layer 85 of the semiconductor module 100 involved in this embodiment, in top view, a semiconductor module with sidewalls and metal layers that do not overlap at their corners and only overlap at one edge is prepared.

[0099] After conducting simulations in which the semiconductor modules of the respective examples, the first comparative example, and the second comparative example were subjected to temperature cycling with the ambient temperature repeatedly changing between -40°C and 125°C, it was confirmed that the plastic strain amplitude of each example could be suppressed to 0.14% relative to 0.21% in the first comparative example and 0.22% in the second comparative example.

[0100] As with the semiconductor module 100 of this embodiment, in plan view, preferably, the outline of at least one corner of the metal layer 85 is located between the inner and outer sides of the inclined portion 37 of the sidewall 36, and the portion of the metal layer 85 other than the corner does not overlap with the sidewall 36. However, as a variation of the semiconductor module 100, in plan view, even with a structure in which the outline of at least one corner of the metal layer 85 is located outside the inclined portion 37 of the sidewall 36 and the portion of the metal layer 85 other than the corner does not overlap with the sidewall 36, the above simulation confirms that the plastic strain amplitude can be suppressed to 0.16%.

[0101] Figure 10 This is a diagram illustrating a modified example of sidewall 36, namely sidewall 38, in a semiconductor module 100 according to one embodiment of the present invention. As a comparison with... Figures 1 to 9 The differences in the semiconductor module 100 involved in the described implementation are as follows: Figure 10 As shown, the sidewall 38 has a pair of inclined portions 37L, 37L and a pair of inclined portions 37S, 37S. Only the metal layer 85 of the circuit board 76 of the W phase unit 70W, which is located on the side closest to the positive y-axis, among the U phase unit 70U, V phase unit 70V and W phase unit 70W, overlaps with the inclined portion 37L of the sidewall 38 located on the side closest to the positive x-axis and the positive y-axis.

[0102] like Figure 10 As shown, in this example, inclined portions 37L, 37S, and 37S, viewed from above, are respectively located at two sets of corners along the diagonal direction of the refrigerant flow section 92. The lengths of inclined portions 37L and 37S can be the same or different. Furthermore, the extending direction of inclined portion 37L is at an angle θ to the y-axis direction. L Intersecting. Furthermore, the extending direction of the inclined section 37s is at an angle θ to the y-axis direction. S Intersection. θ L and θ SThey can be the same or different. Additionally, in this example, the length of the sidewall element 38S can also be longer than the length of one side of the metal layer 85 in the x-direction. Even with the semiconductor module 100 involved in this variation, the same effect is achieved.

[0103] Figure 11 This diagram illustrates a modified example of sidewall 36 (sidewall 39) and a modified example of metal layer 85 (metal layer 86) in a semiconductor module 100 according to an embodiment of the present invention. As a reference for use... Figures 1 to 9 The difference in the semiconductor module 100 described in the embodiment is that, in top view, the sidewall 39 has inclined portions 37 only at the two corners located diagonally in the direction of the refrigerant flow section 92. As described above, the aspect ratio of the metal layer 86 is different from that of the metal layer 85, the length of the side in the x-axis direction is relatively long, and the center of each circuit board 76 in the x-axis direction is arranged on the center line CL. Even with the semiconductor module 100 according to this modified example, the same effect as described above is achieved.

[0104] Figures 12-15 The sidewalls 36, 38, and 39 shown are common in that they each include a set of opposing sidewall elements 36L, 38L, and 39L extending along the y-axis, a set of opposing sidewall elements 36S, 38S, and 39S extending along the x-axis, and inclined portions 37, 37S, and 37L connecting the ends of the sidewall elements 36L, 38L, and 39L with the ends of the sidewall elements 36S, 38S, and 39S. The inclined portions 37, 37S, and 37L may be inclined toward the inner side of the sidewalls 36, 38, and 39 and extend to intersect at an angle of, for example, 30 degrees to 60 degrees relative to the y-axis.

[0105] Figure 12 , Figure 13 , Figure 14 , Figure 15 Figures show modified examples of metal layers 87, 88, 89, and 90 of the semiconductor device 70 in a semiconductor module 100 according to one embodiment of the present invention. Metal layers 87, 88, 89, and 90 are generally rectangular in top view, having a set of sides extending along the x-axis and a set of sides extending along the y-axis, and including multiple corners or rounded arcs at their corners formed by chamfering.

[0106] As for use Figures 1 to 11 The differences in the semiconductor module 100 involved in the described implementation method are as follows: Figure 12 The metal layer 87 shown has a dodecagon with an interior angle of 150° at its corners when viewed from above. Figure 13 The metal layer 88 shown has a 16-sided polygon with an interior angle of 157.5° at its corners when viewed from above. Additionally, Figure 14The metal layer 89 shown, when viewed from above, has an octagonal shape with two different corners, one of 120° and the other of 150°. Figure 15 The metal layer 90 shown, when viewed from above, has a shape without corners, including the arc connecting the two sides adjacent to the corners. Even the semiconductor module 100 involved in these variations achieves the same effect as described above.

[0107] Figure 16 This is a schematic diagram illustrating a vehicle 200 according to one embodiment of the present invention. Vehicle 200 is a vehicle that uses power to generate at least a portion of propulsion. As an example, vehicle 200 is an electric vehicle that uses a power drive device such as an electric motor to generate all propulsion, or a hybrid vehicle that uses a power drive device such as an electric motor in combination with an internal combustion engine driven by a fuel such as gasoline.

[0108] The vehicle 200 includes a control device 210 (external device) for controlling power drive equipment such as electric motors. The control device 210 includes a semiconductor module 100. The semiconductor module 100 can control the power supplied to the power drive equipment.

[0109] Figure 17 This is a main circuit diagram of the semiconductor module 100 according to various embodiments of the present invention. The semiconductor module 100 functions as a three-phase AC inverter circuit with output terminals U, V and W, and can be part of an on-board unit that drives the electric motor of a vehicle.

[0110] In semiconductor module 100, semiconductor chips 78-1, 78-2, and 78-3 can form the upper bridge arm, and semiconductor chips 78-4, 78-5, and 78-6 can form the lower bridge arm. A group of semiconductor chips 78-1 and 78-4 can form a branch (U phase). A group of semiconductor chips 78-2 and 78-5, and a group of semiconductor chips 78-3 and 78-6 can also form branches (V phase and W phase). In semiconductor chip 78-4, 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 semiconductor chip 78-1, 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 semiconductor chips 78-5 and 78-6, 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. Furthermore, in semiconductor chips 78-2 and 78-3, the emitter electrode can be electrically connected to the output terminals V and W respectively, and the collector electrode can be electrically connected to the input terminals P2 and P3 respectively.

[0111] Semiconductor chips 78-1 to 78-6 can switch on and off alternately according to signals input to their corresponding control terminals. In this example, each semiconductor chip 78 can generate heat during switching. Input terminals P1, P2, and P3 can be connected to the positive terminal of an external power supply, input terminals N1, N2, and N3 can be connected to the negative terminal of an external power supply, and output terminals U, V, and W can be connected to a load. Input terminals P1, P2, and P3 can be electrically connected to each other, and can also be electrically connected to other input terminals N1, N2, and N3.

[0112] In semiconductor module 100, multiple semiconductor chips 78-1 to 78-6 can each be RC-IGBT (reverse conduction IGBT) semiconductor chips. Additionally, semiconductor chips 78-1 to 78-6 can each contain combinations of transistors such as MOSFETs and IGBTs, and diodes.

[0113] In the description of the above embodiments, terms such as "approximately the same", "approximately consistent", "approximately constant", "approximately symmetrical", "approximately rhomboid", "approximately rectangular", etc., are sometimes used with "approximately" to express a specific state. However, the intention of these terms is not only to include strictly being that specific state, but also to include approximately being that specific state.

[0114] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be made based on the above embodiments, which will be apparent to those skilled in the art. As can be seen from the claims, such changes or improvements are also included within the technical scope of the present invention.

[0115] For example, in the above embodiments, the structure of the semiconductor module 100 including three semiconductor devices 70 has been described, but instead, it may include one, two or more semiconductor devices 70.

[0116] For example, in the refrigerant flow section 92 defined by sidewalls 36, 38, and 39, a first refrigerant flow path 30-1 can be placed side-by-side on one side of the fin region 95 in the short-side direction, and a second refrigerant flow path 30-2 can be placed side-by-side on the other side. Cooling needle-shaped fins 94 are arranged between the first and second refrigerant flow paths 30-1 and 30-2. Furthermore, for example, the cooling needle-shaped fins 94 can be arranged in a grid pattern, preferably in an oblique grid pattern or a diamond grid pattern. Additionally, for example, the inlet 41 and outlet 42, adjacent to the fin region 95 in the refrigerant flow section 92, can be arranged diagonally. Furthermore, for example, when viewed from above, the length of the openings of the inlet 41 and outlet 42 in the direction of the long side 96 can be greater than the length in the direction of the short side 93.

[0117] For example, in the above embodiment, a structure in which the top plate 20, side walls 36, 38, 39, and cooling needle-shaped fins 94 are integrally formed in the chassis 40 has been described. However, alternatively, the top plate 20, side walls 36, and cooling needle-shaped fins 94 can also be formed separately and then fixed to each other using a fixing agent 98 or the like. Alternatively, the top plate 20 and side walls 36 can be formed integrally, and the separately formed cooling needle-shaped fins 94 can be fixed to the top plate 20. Alternatively, the top plate 20 and cooling needle-shaped fins 94 can be formed integrally, and the separately formed side walls 36 can be fixed to the top plate 20 using a fixing agent 98 or the like. Furthermore, the side walls 36 and the bottom plate 64 can be formed integrally, for example, by stretching, and the separately formed top plate 20 can be fixed to the side walls 36, for example, by brazing using a fixing agent 98 or the like. In this case, the sidewall 36 and the like extend along the xy plane to the area where the fastening part 21 of the top plate 20 is located, and the extended surface of the sidewall 36 and the like can be connected to the lower surface 24 of the top plate 20.

[0118] Alternatively, for example, in the above embodiment, a structure was described in which the cooling needle-shaped fin 94 is integrally formed with the top plate 20 and extends toward the bottom plate 64. However, instead, the cooling needle-shaped fin 94 may also be integrally formed with the bottom plate 64 and extend from the bottom plate 64 toward the top plate 20. In this case, the front end of the cooling needle-shaped fin 94 can be fixed to the top plate 20 with a fixing agent 98 or the like.

[0119] Furthermore, for example, in the above embodiment, a structure in which the cooling needle-shaped fins 94 extend perpendicularly to the top plate 20 and the bottom plate 64 along the normal direction of the main surface of the top plate 20, that is, extending perpendicularly to the top plate 20 and the bottom plate 64, has been described. However, instead, the cooling needle-shaped fins 94 may also extend at an angle to the normal direction of the main surface of the top plate 20 between the top plate 20 and the bottom plate 64. Additionally, the cross-sectional dimensions of the cooling needle-shaped fins 94 in the xy-plane may be constant or variable in the z-axis direction. As a more specific example, they may extend from either the top plate 20 or the bottom plate 64 in a manner where the front end becomes thinner towards the front end.

[0120] Furthermore, for example, in the above embodiment, the structure in which the inlet 41 for introducing refrigerant into the refrigerant circulation section 92 and the outlet 42 for discharging refrigerant from the refrigerant circulation section 92 are formed on the base plate 64 has been described. However, instead, the inlet 41 and the outlet 42 may also be formed on the side walls 36, 38, and 39. In this case, the inlet 41 and the outlet 42 may be formed on two opposite sides of the side wall 36, etc., along the x-axis direction.

[0121] Furthermore, in the above embodiment, the inner sides of the sidewalls 36, 38, and 39 were described as straight lines in top view, but they are not limited to straight lines; they could also be broken lines or curves. For example, in top view, the inner side of the sidewall 36, etc., could be an arc-shaped curve that expands on one side of the refrigerant flow section 92, and could also be an arc-shaped curve that is concave on the opposite side.

[0122] It should be noted that the execution order of actions, sequences, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specification, and drawings can be implemented in any order, unless specifically stated as "before" or "before," and unless the output of a previous process is used for a subsequent process. The use of terms such as "firstly" and "next" in the description of the action flow in the claims, specification, and drawings is for convenience, but this does not imply that the actions must be performed in that order.

[0123] Label Explanation

[0124] 10. Cooling device

[0125] 20 top slabs,

[0126] 21 Fastening parts,

[0127] 22. Upper surface,

[0128] 24 Lower surface,

[0129] 30. Refrigerant flow path

[0130] 30-1 First refrigerant flow path,

[0131] 30-2 Second refrigerant flow path,

[0132] Side walls 36, 38, and 39

[0133] Sidewall elements for 36S, 36L, 38S, 38L, 39S, and 39L.

[0134] Inclined sections 37, 37S, and 37L

[0135] 40 chassis,

[0136] 41. Entrance

[0137] 42 Exports

[0138] 64 base plate,

[0139] 70 Semiconductor devices,

[0140] 70U U-phase unit,

[0141] 70V V-phase unit,

[0142] 70W phase unit,

[0143] 72. Storage Department

[0144] 74 Sealing part,

[0145] 76 Circuit board,

[0146] 78 Semiconductor chips,

[0147] 79 Solder,

[0148] 80 through hole,

[0149] 81 Insulation Board

[0150] 83. Circuit layer.

[0151] Metal layers 85, 86, 87, 88, 89, and 90.

[0152] 92. Refrigerant Distribution Department

[0153] 93. Short side,

[0154] 96 Long side,

[0155] 94 Cooling needle-shaped fins,

[0156] 95 Fin area,

[0157] 98 Fixative

[0158] 100 semiconductor modules,

[0159] 200 vehicles

[0160] 210 Control device.

Claims

1. A semiconductor module, comprising a semiconductor device and a cooling device, characterized in that, The semiconductor device includes a semiconductor chip and a circuit board on which the semiconductor chip is mounted. The cooling device includes: A top plate on which the semiconductor device is mounted; The sidewall connected to the top plate; A bottom plate connected to the sidewall and opposite to the top plate; and The refrigerant flow section, defined by the top plate, the side walls, and the bottom plate, is a roughly rectangular section with a long side and a short side, parallel to the main surface of the top plate, used for refrigerant flow. The circuit board is a generally rectangular laminated substrate, comprising, in sequence, an insulating plate having an upper surface and a lower surface, a circuit layer disposed on the upper surface, and a metal layer disposed on the lower surface, wherein the metal layer is fixed to the top plate with solder. Viewed from above, the sidewall includes an inclined portion at at least one corner, the inclined portion being inclined inward at an angle relative to both the direction of the long side and the direction of the short side. Viewed from above, at least one corner of the metal layer at least partially overlaps with the inclined portion.

2. The semiconductor module as described in claim 1, characterized in that, Viewed from above, the outline of at least one corner of the metal layer is located between the inner and outer sides of the inclined portion.

3. The semiconductor module as described in claim 2, characterized in that, Viewed from above, the portion of the metal layer other than the corner does not overlap with the sidewall.

4. The semiconductor module as described in claim 1, characterized in that, Viewed from above, the portion of the metal layer other than the corner does not overlap with the sidewall.

5. The semiconductor module according to any one of claims 1 to 4, characterized in that, The sidewall includes two inclined portions at at least two corners. Viewed from above, the two corners of the metal layer at least partially overlap with the two inclined portions.

6. The semiconductor module according to any one of claims 1 to 4, characterized in that, In the direction of the short side, the length of one side of the inner side of the sidewall is shorter than the length of one side of the metal layer of the circuit board.

7. The semiconductor module according to any one of claims 1 to 4, characterized in that, The insulating plate contains ceramic.

8. The semiconductor module according to any one of claims 1 to 4, characterized in that, The top plate and the side wall are integrated as one unit.

9. The semiconductor module as described in claim 8, characterized in that, The top plate and the side wall are formed as one unit.

10. The semiconductor module as claimed in claim 8, characterized in that, The top plate and the side wall are fixed with a fixative.

11. The semiconductor module as claimed in claim 8, characterized in that, The thickness of the top plate section in a plane orthogonal to the top view direction is thicker on the outer side of the sidewall than on the inner side.

12. A semiconductor module, comprising a semiconductor device and a cooling device, characterized in that, The semiconductor device has: Semiconductor chips; as well as A circuit board comprising an insulating plate having an upper surface and a lower surface, a circuit layer disposed on the upper surface, and a metal layer disposed on the lower surface, wherein the semiconductor chip is mounted on the circuit layer. The cooling device includes: A top plate on which the semiconductor device is mounted; The sidewall connected to the top plate; A bottom plate connected to the sidewall and opposite to the top plate; and A refrigerant flow section, defined by the top plate, the side walls, and the bottom plate, is used to allow refrigerant to flow. The metal layer of the circuit board is fixed to the top plate with solder. The sidewall includes a set of first sidewall elements extending in one direction and opposite to each other, a set of second sidewall elements extending in another direction and opposite to each other, and an inclined portion connecting the ends of the first sidewall elements and the ends of the second sidewall elements. Viewed from above, the metal layer is roughly rectangular, with its corners partially overlapping the inclined portion.

13. The semiconductor module as described in claim 12, characterized in that, Viewed from above, the one direction is approximately orthogonal to the other direction, and the extension direction of the inclined portion intersects the one direction at an angle of more than 30 degrees and less than 60 degrees.

14. The semiconductor module as described in claim 12 or 13, characterized in that, The sidewall includes four inclined portions. Viewed from above, the length of the second sidewall element is shorter than the length of the first sidewall element, and the length of the second sidewall element is shorter than the length of one side of the metal layer.

15. The semiconductor module as described in claim 12 or 13, characterized in that, The sidewall includes two inclined portions.

16. A vehicle, characterized in that, Includes the semiconductor module as described in any one of claims 1 to 15.

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