Semiconductor module and vehicle

Abstract

Under repeated temperature changes due to external environment and self-heating, the cooling efficiency is reduced due to the loss of flow rate of the refrigerant in the cooler, and the stress and plastic strain at the adhesive fixing the semiconductor element to the cooler due to thermal deformation of the cooler are increased. The semiconductor module of the present application includes a semiconductor device having a semiconductor chip, a circuit substrate on which the semiconductor chip is mounted, and a resin structure sealing the semiconductor chip, and a cooling device having a top plate, a side wall, a bottom plate, a refrigerant flow passage, a plurality of fins, and a reinforcing pin, wherein a portion of the metal layer overlaps the cooling region in plan view, and the portion other than the portion overlaps one of the first and second communication regions, and the reinforcing pin is disposed in the one communication region.

Description

Technical Field

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

[0002] Previously, a semiconductor module was known, which included multiple semiconductor elements such as a power semiconductor chip mounted on a cooler containing a heat sink (see, for example, Patent Documents 1-4).

[0003] Existing technical documents

[0004] Patent documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-092468

[0006] [Patent Document 2] Japanese Patent Application Publication No. 2017-050375

[0007] [Patent Document 3] WO2015 / 033724

[0008] [Patent Document 4] Japanese Patent Application Publication No. 2016-225339

[0009] [Patent Document 5] Japanese Patent Application Publication No. 2010-161203 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] In the aforementioned semiconductor module, the circuit board is fixed to the cooler with an adhesive. However, under conditions where the temperature fluctuates repeatedly due to external environment and self-heating, it is impossible to suppress the reduction in cooling efficiency caused by the loss of refrigerant flow rate in the cooler. At the same time, it is impossible to suppress the generation of large stress and plastic strain in the adhesive due to the thermal deformation of the cooler.

[0012] Technical means for solving technical problems

[0013] 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 include a semiconductor chip, a circuit board on which the semiconductor chip is mounted, and a resin structure sealing the semiconductor chip. The cooling device may have a top plate on which the circuit board and resin structure of the semiconductor device are fixed to a main surface. The cooling device may have a sidewall connected to the top plate. The cooling device may have a bottom plate connected to the sidewall and opposite to the top plate. The cooling device may have a refrigerant flow section defined by the top plate, sidewall, and bottom plate for allowing refrigerant to flow. The cooling device may have an inlet for introducing refrigerant into the refrigerant flow section. The cooling device may have an outlet for discharging refrigerant from the refrigerant flow section. The cooling device may have a plurality of fins and reinforcing pins disposed in the refrigerant flow section and extending to connect between the top plate and the bottom plate. The refrigerant flow section may include a cooling area with a plurality of fins disposed thereon. The refrigerant flow section may include a first connecting region adjacent to one side of the cooling region, communicating with an inlet, and without multiple fins. The refrigerant flow section may also include a second connecting region adjacent to the opposite side of one side of the cooling region, communicating with an outlet, and without multiple fins. The circuit board may be a laminated substrate comprising, in sequence, an insulating plate having an upper and a lower surface, a circuit layer disposed on the upper surface, and a metal layer disposed on the lower surface. In top view, a portion of the metal layer may overlap with the cooling region, and the remaining portion may overlap with one of the connecting regions of the first and second connecting regions. A reinforcing pin may be disposed in one of the connecting regions. In a plane parallel to the main surface of the top plate, the cross-sectional area of ​​the reinforcing pin may be smaller than the cross-sectional area of ​​at least one of the multiple fins.

[0014] When viewed from above, at least a portion of the reinforcing pin can overlap with the metal layer.

[0015] The metal layer can be rectangular when viewed from above. When viewed from above, at least a portion of the reinforcing pin can overlap with the corner of the rectangle of the metal layer.

[0016] When viewed from above, a portion of the reinforcing pin may overlap with the corner of the rectangular metal layer, while the portion other than this may not overlap with the metal layer.

[0017] When viewed from above, at least a portion of the reinforcing pin can overlap with the portion of the corner of the rectangular metal layer furthest from the cooling area.

[0018] The metal layer can be rectangular when viewed from above. When viewed from above, the reinforcing pins may not overlap with the metal layer and may be located near the corners of the rectangular shape of the metal layer.

[0019] When viewed from above, the reinforcing pin is positioned at a distance greater than 0 mm and less than 2 mm from the portion of the rectangular corner of the metal layer furthest from the cooling area, along the direction away from the cooling area.

[0020] A semiconductor device may include two or more circuit boards. When viewed from above, only one reinforcing pin may be positioned between the corners of two rectangular sections of adjacent metal layers.

[0021] The refrigerant flow section can be rectangular when viewed from above. When viewed from above, the reinforcing pin can be located between the corners of the rectangular refrigerant flow section and the metal layer.

[0022] The cross-section of the reinforcing pin, parallel to the main surface of the top plate, can be circular.

[0023] The cross-sectional shape of the multiple fins parallel to the main surface of the top plate can be rectangular. The multiple fins can be arranged in the refrigerant flow section such that when the refrigerant flows in the refrigerant flow section, none of the sides of the rectangle is orthogonal to the main flow direction of the refrigerant in the cooling zone.

[0024] The cross-sectional shape of the reinforcing pin parallel to the main surface of the top plate can be non-polygonal. The cross-sectional shape of multiple fins parallel to the main surface of the top plate can be polygonal.

[0025] The density of multiple reinforcing pins disposed in at least one connected region can be sparser than the density of multiple fins disposed in the cooling region.

[0026] The insulating board may contain ceramic. The metal layer may be fixed to the main surface of the top plate using solder.

[0027] The resin structure may include a sealing portion for sealing the semiconductor chip and a receiving portion surrounding the sealing portion. The receiving portion may be fixed to the main surface of the top plate by an adhesive.

[0028] A second aspect of the present invention provides a vehicle that includes the semiconductor module involved in the first aspect.

[0029] Furthermore, the above summary of the invention does not list all the essential features of the invention. In addition, sub-combinations of these feature groups can also constitute an invention. Attached Figure Description

[0030] Figure 1 This is a schematic perspective view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention.

[0031] Figure 2 This is a schematic perspective view illustrating an example of a cooling device 10 for a semiconductor module 100 according to an embodiment of the present invention.

[0032] 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.

[0033] Figure 4 yes Figure 3 A magnified view of the area "A" indicated by the dashed line.

[0034] Figure 5 This is a diagram illustrating an example of the configuration of the cooling region 95 of the cooling device 10 in a semiconductor module 100 according to an embodiment of the present invention, the configuration of the metal layer 85 of the semiconductor device 70, the configuration and shape of the fins 94, the configuration and shape of the reinforcing pins 97, and the flow direction of the refrigerant.

[0035] Figure 6 This is a diagram illustrating a modified example of the configuration relationship between the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0036] Figure 7 This is a diagram illustrating a modified example of the configuration relationship between the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0037] Figure 8 This is a diagram illustrating a modified example of the configuration relationship between the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0038] Figure 9 This is a diagram illustrating a modified example of the configuration relationship between the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0039] Figure 10 This is a diagram illustrating a modified example of the configuration relationship between the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0040] Figure 11 This is a diagram illustrating a schematic representation of a vehicle 200 according to one embodiment of the present invention.

[0041] Figure 12 This is a main circuit diagram of a semiconductor module 100 according to one embodiment of the present invention. Detailed Implementation

[0042] The present invention will now be described through embodiments thereof; however, these embodiments do not limit the scope of the invention as defined in the 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.

[0043] 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. Furthermore, 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. Figure 4 yes Figure 3 A magnified view of region A in the image. Furthermore, Figure 5 This is a diagram illustrating an example of the configuration of the cooling region 95 of the cooling device 10 in a semiconductor module 100 according to an embodiment of the present invention, the configuration of the metal layer 85 of the semiconductor device 70, the configuration and shape of the fins 94, the configuration and arrangement of the reinforcing pins 97, and the flow direction of the refrigerant.

[0044] For clarity, Figure 1 and Figure 2 In the middle, the following was omitted. Figure 3 and Figure 4 The illustration shows the resin structure 71. Figure 3 This illustrates an imaginary cut using the xz plane. Figure 1 The semiconductor chip 78 and the W-phase unit 70W in the semiconductor module 100 shown Figure 2 The state of both ends of the outlet 42 of the cooling device 10 shown. Figure 4 In the diagram, the thickness of the fastening part 21 of the top plate 20 in the z-axis direction is represented by T1, the thickness of the cooling area 95 of the top plate 20 in the z-axis direction is represented by T2, the thickness of the side wall 36 in the x-axis direction is represented by T3, and the thickness of the bottom plate 64 in the z-axis direction is represented by T4. Figure 5 middle, Figure 1 The metal layers 85 of the U-phase unit 70U, V-phase unit 70V and W-phase unit 70W are shown by dashed lines.

[0045] The semiconductor module 100 includes a semiconductor device 70 and a cooling device 10. In this embodiment, the semiconductor device 70 is mounted on the cooling device 10. In this embodiment, the surface of the cooling device 10 on which the 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 the cooling device 10 toward the 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, a top view refers to the view of the semiconductor module 100 from the positive z-axis direction.

[0046] The semiconductor device 70 includes a semiconductor chip 78, a circuit board 76 on which the semiconductor chip 78 is mounted, and a resin structure 71 for sealing the semiconductor chip 78. The semiconductor device 70 may include two or more circuit boards 76. In this embodiment, the semiconductor device 70 includes three circuit boards 76, and the three circuit boards 76 are arranged in the y-axis direction on the cooling device 10. One or more semiconductor chips 78 may be mounted on each circuit board 76. In this embodiment, two semiconductor chips 78 are mounted on each circuit board 76, and the two semiconductor chips 78 are arranged in the y-axis direction on the circuit board 76.

[0047] In this embodiment, the semiconductor module 100 functions as a device constituting a three-phase AC inverter. For example... Figure 1 As shown, the semiconductor device 70 of this embodiment, as a power semiconductor device, includes: a U-phase unit 70U, which includes a circuit board 76, semiconductor chips 78-1 and 78-4; a V-phase unit 70V, which includes a circuit board 76, semiconductor chips 78-2 and 78-5; and a W-phase unit 70W, which includes a circuit board 76, semiconductor chips 78-3 and 78-6. 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 operated.

[0048] 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. Semiconductor chip 78 can also be an RC-IGBT (RC-IGBT) in which the IGBT and FWD are formed on a single semiconductor substrate. In an RC-IGBT, the IGBT and FWD can be connected in parallel in reverse.

[0049] The lower surface electrode of the semiconductor chip 78 is connected to the upper surface of the circuit substrate 76. In this embodiment, the semiconductor chip 78 is 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).

[0050] The semiconductor chip 78, including switching elements such as IGBTs and MOSFETs, has control electrodes. The semiconductor module 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.

[0051] like Figure 3 and Figure 4 As shown, the circuit board 76 is a stacked substrate that 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.

[0052] 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. In this embodiment, the circuit board 76 is fixed to the upper surface of the cooling device 10 via a metal layer 85 and solder 79. As an example, two semiconductor chips 78 are fixed to the upper surface of the circuit board 76 in this embodiment.

[0053] 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 in this embodiment comprises ceramic. The insulating plate 81 can be formed using ceramic materials such as alumina (Al2O3), aluminum nitride (AlN), or silicon nitride (Si3N4). The insulating plate 81 in this embodiment is rectangular when viewed from above.

[0054] In this specification, a rectangle can be a quadrilateral or a rectangular shape. Furthermore, at least one corner can be a chamfered or rounded shape. For example, a rectangle can include an octagon, dodecagon, hexagon, etc., with each of its four corners chamfered. Additionally, in this specification, a corner can be not only a point where two sides intersect, but also a region containing that point. When a corner is chamfered with a C-shape, it can be any point on the side of the C-shaped chamfer connecting one corner to another, or a region containing that side. Similarly, when a corner is chamfered with an R-shape, it can be any point on the R-shaped chamfer, or a region containing that point.

[0055] The circuit layer 83 and the metal layer 85 can be a substrate containing conductive materials such as copper or copper alloys. Similar to the insulating plate 81, the circuit layer 83 and the metal layer 85 in this embodiment are rectangular when viewed from above.

[0056] The circuit layer 83 is fixed to the upper surface of the insulating plate 81 by solder or brazing filler metal. The semiconductor chip 78 is electrically or mechanically connected to the upper surface of the circuit layer 83 by solder or other means, that is, directly connected to the upper surface of the circuit layer 83 in a circuit manner. In addition, the circuit layer 83 can be electrically connected to other conductive components by wires or the like. Furthermore, the circuit layer 83 can be directly bonded (DCB: Direct Copper Bonding) to the upper surface of the insulating plate 81.

[0057] like Figure 3 and Figure 4 As shown, the resin structure 71 of this embodiment includes a sealing portion 74 for sealing the semiconductor chip 78 and a receiving portion 72 surrounding the sealing portion 74. The sealing portion 74 is, for example, an insulating member containing a resin such as silicone gel or epoxy resin. In addition to the semiconductor chip 78, the sealing portion 74 of this embodiment also seals the circuit board 76 and other circuit elements.

[0058] The housing 72 is, for example, a frame formed of an insulating material such as thermosetting resin or UV-curable resin. In this embodiment, the housing 72 is configured to surround the area on the upper surface 22 of the top plate 20 where the circuit board 76 and the like are disposed. In other words, the housing 72 of this embodiment has an internal space capable of housing the semiconductor chip 78, the circuit board 76, and other circuit elements. The housing 72 can be adhered to the upper surface 22 of the top plate 20. As an example, the sealing portion 74 is formed by filling the internal space of the housing 72 with the resin and then curing it. The resin structure 71 may only include the sealing portion 74 and not the housing 72.

[0059] The cooling device 10 includes a top plate 20, a side wall 36, a bottom plate 64, a refrigerant flow section 92, an inlet 41, an outlet 42, a plurality of fins 94, and reinforcing pins 97. In this embodiment, the top plate 20, the side wall 36, the plurality of fins 94, and the reinforcing pins 97 can be collectively referred to as the substrate 40.

[0060] The top plate 20 is a plate-shaped member having a main surface extending in the xy plane. The circuit board 76 of the semiconductor device 70 and the resin structure 71 are fixed to the main surface of the top plate 20. In this embodiment, the top plate 20 is substantially rectangular with a long side and a short side when viewed from above. In addition, when referred to as a rectangle, square, quadrilateral, rhombus, polygon, etc. in this specification, at least one corner of these shapes may be a chamfered shape or a smooth shape.

[0061] In this embodiment, the short side of the top plate 20 is parallel to the x-axis, and the long side is parallel to the y-axis. The top plate 20 includes a fastening portion 21 for fastening an external device to which the semiconductor module 100 is mounted. Viewed from above, the fastening portions 21 are located at the four corners of the rectangular top plate 20. Each fastening portion 21 has a through hole 80 for inserting a sleeve or similar external device. In this embodiment, the fastening portion 21 has one through hole 80 at each of the four corners of the rectangular top plate 20, for a total of four through holes 80.

[0062] like Figure 3 As shown, the top plate 20 has an upper surface (front) 22 and a lower surface (back) 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 aluminum. The top plate 20 may have a plating such as nickel formed on its surface.

[0063] In this embodiment, the circuit board 76 of the semiconductor device 70 is directly fixed to the upper surface 22 of the top plate 20 by solder 79. More specifically, the metal layer 85 of the circuit board 76 is fixed to the main surface of the top plate 20 by solder 79. Heat generated in each semiconductor chip 78 is transferred to the top plate 20. The top plate 20, the circuit board 76, and the semiconductor chips 78 are arranged in this order oriented towards the positive z-axis. The top plate 20 and the circuit board 76, as well as the circuit board 76 and the semiconductor chips 78, can be thermally connected. In this embodiment, the components are fixed together by solder 79, and the components are thermally connected by the solder 79. The aforementioned receiving portion 72 is fixed to the main surface of the top plate 20 in this embodiment by adhesive.

[0064] The sidewall 36 is connected to the top plate 20. In this embodiment, the sidewall 36 is integrally formed with the top plate 20. As an example, the sidewall 36 is formed of metal; more specifically, like the top plate 20, the sidewall 36 is formed of a metal containing aluminum. The sidewall 36 has a substantially constant thickness and forms the side of the cooling device 10. The thickness of the sidewall 36 can be, for example, more than 1 mm and less than 3 mm.

[0065] The sidewall 36 of this embodiment has a substantially rectangular outline in the xy plane, the outline having a long side and a short side. More specifically, the sidewall 36 of this embodiment includes a set of sidewall elements 36L, which extend in the y-axis direction and are opposite to each other; and a set of sidewall elements 36S, which extend in the x-axis direction and are opposite to each other, the set of sidewall elements 36L forming the long side of the rectangle, and the set of sidewall elements 36S forming the short side of the rectangle.

[0066] In a top view, the extending directions of sidewall element 36L and sidewall element 36S are approximately orthogonal to each other within a range of 85 to 95 degrees, and preferably intersect each other at 90°. The length of sidewall element 36S may be shorter than the length of sidewall element 36L. Sidewall element 36L may be straight or contain curves in a top view.

[0067] Furthermore, in this embodiment, the sidewall 36 is located further inward than the fastening portion 21 of the top plate 20 when viewed from above, and extends from the top plate 20 in the negative z-axis direction. The outline can refer to the lines that form the shape of an object.

[0068] Furthermore, the sidewall 36 of this embodiment includes an inclined portion 37 connecting the end of the sidewall element 36S and the end of the sidewall element 36L. Figure 5 In the illustration, the inclined portion 37 is depicted as a mesh-like area, and the same applies in the following figures. The sidewall 36 may not include the inclined portion 37.

[0069] When viewed from above, the inclined portion 37 is inclined toward the interior of the annular sidewall 36, such that the inclined portion 37 has angles relative to the y-axis and x-axis directions, respectively. The interior of the annular sidewall 36 may refer to one side of the region surrounded by the sidewall 36 having a rectangular outline. When viewed from above, the sidewall 36 containing the inclined portion 37 may have a polygonal outline, such as an n-sided polygon (n is an integer greater than 5), preferably a hexagonal or octagonal outline.

[0070] The base plate 64 is connected to the side wall 36 and faces the top plate 20. In this embodiment, the base plate 64 is a plate-shaped component. In top view, the top plate 64 is a rectangle with a long side and a short side. In this embodiment, the short side of the base plate 64 is parallel to the x-axis, and the long side is parallel to the y-axis.

[0071] The base plate 64 can be configured to be in close contact with the lower end of the side wall 36 in the negative z-axis direction, either directly or indirectly. Indirect close contact refers to a state where the lower end of the side wall 36 and the base plate 64 are in close contact via an adhesive 98, such as a sealing material, adhesive, or brazing material, disposed between the lower end of the side wall 36 and the base plate 64. In this embodiment, the base plate 64 is configured to be in close contact with the lower end of the side wall 36 via the adhesive 98. As an example, the base plate 64 is formed of metal; more specifically, similar to the substrate 40, the base plate 64 is formed of a metal containing aluminum.

[0072] The lower end of the sidewall 36 and the base plate 64 are preferably brazed together. In this case, the brazing material is preferably a metal with a melting point lower than that of the substrate 40 and the base plate 64.

[0073] The refrigerant flow section 92 is a space for the flow of refrigerants such as LLC or water, defined by the top plate 20, side walls 36, and bottom plate 64. In other words, the side walls 36 are configured to surround the refrigerant flow section 92 in the xy plane, and the top plate 20 and bottom plate 64 are configured to sandwich the refrigerant flow section 92 in the z-axis direction and be opposite to each other. 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, the refrigerant flow section 92 is rectangular when viewed from above. More specifically, as... Figure 5 As shown, the refrigerant flow section 92 is a rectangle with a long side 96 and a short side 93 in cross-section parallel to the main surface of the top plate 20. In this embodiment, 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.

[0074] The refrigerant flow section 92 can be sealed by the top plate 20, the side wall 36, and the bottom plate 64. In this case, the lower end of the side wall 36 and the bottom plate 64 can be in close contact. In addition, close contact means that the refrigerant inside the refrigerant flow section 92 does not leak from the close contact portion.

[0075] Inlet 41 is a through hole for introducing refrigerant into refrigerant circulation section 92, and outlet 42 is a through hole for discharging refrigerant from refrigerant circulation section 92. In this embodiment, inlet 41 and outlet 42 are formed on base plate 64.

[0076] Inlet 41 and outlet 42 are located on one side and the opposite side of the cooling device 10, respectively, in the x-axis direction, and on one side and the opposite side of the cooling device 10, respectively, in the y-axis direction. That is, inlet 41 and outlet 42 are located at opposite ends of the refrigerant flow section 92 in the xy plane, along the diagonal direction of the rectangular refrigerant flow section 92.

[0077] Inlet 41 and outlet 42 can be connected to an external refrigerant supply source. This refrigerant supply source allows refrigerant to flow into and out of the refrigerant circulation section 92 via inlet 41 and outlet 42. As an example, the refrigerant supply source has a flange with openings for refrigerant inflow and outflow, and the cooling device 10 can be fixed to this flange such that inlet 41 and outlet 42 of the cooling device 10 communicate with these openings via, for example, rubber O-rings. Therefore, refrigerant can be supplied to the cooling device 10 from the external refrigerant supply source via inlet 41, and the refrigerant can circulate within the refrigerant circulation section 92 before being discharged back to the refrigerant supply source via outlet 42. Alternatively, inlet 41 and outlet 42 can be connected to pipes respectively communicating with the external refrigerant supply source; in other words, the cooling device 10 can be connected to the external refrigerant supply source via two pipes.

[0078] Multiple fins 94 are disposed in the refrigerant flow section 92 and extend to connect between the top plate 20 and the bottom plate 64. The refrigerant flow section 92 includes a cooling region 95 with multiple fins 94 disposed thereon. Figure 2 In the diagram, cooling area 95 is represented by a dot instead of fin 94. Additionally, in the following description, one or more fins 94 may sometimes be referred to simply as fin 94.

[0079] The cooling area 95 can appear rectangular when viewed from above. For example... Figure 5 As shown, the cooling area 95 in this embodiment is rectangular when viewed from above, with the short side parallel to the x-axis and the long side parallel to the y-axis.

[0080] In the cooling region 95 of this embodiment, the number of fins 94 arranged along the long side 96 of the refrigerant flow section 92 is greater than the number of fins 94 arranged along the short side 93 of the refrigerant flow section 92. The cooling region 95 includes a region provided with fins 94 and flow paths between the fins 94. In addition, the spacing between adjacent fins 94 may be narrower than the width of the fins 94 themselves.

[0081] The refrigerant flow section 92 further includes a first refrigerant flow path 30-1 adjacent to one side of the cooling region 95, and a second refrigerant flow path 30-2 adjacent to the opposite side of the cooling region 95. In other words, the refrigerant flow section 92 includes a first refrigerant flow path 30-1 and a second refrigerant flow path 30-2 arranged sandwiching the cooling region 95 when viewed from above. In this embodiment, the first refrigerant flow path 30-1 is adjacent to the negative side of the cooling region 95 in the x-axis direction, and the second refrigerant flow path 30-2 is adjacent to the positive side of the cooling region 95 in the x-axis direction. These refrigerant flow paths 30 refer to spaces in the refrigerant flow section 92 with a height of a predetermined height (length in the z-axis direction) or higher. The height of the predetermined height may be the distance between the top plate 20 and the bottom plate 64.

[0082] The first refrigerant flow path 30-1 is connected to the inlet 41 and does not have multiple fins 94 configured. Similarly, the second refrigerant flow path 30-2 is connected to the outlet 42 and does not have multiple fins 94 configured. Furthermore, in this embodiment, when viewed from above, the lengths of the first refrigerant flow path 30-1 and the second refrigerant flow path 30-2 in the y-axis direction are each longer than their lengths in the x-axis direction, and they extend in the y-axis direction. Moreover, the first refrigerant flow path 30-1 is an example of a first connected region, and the second refrigerant flow path 30-2 is an example of a second connected region.

[0083] As an example, fin 94 is formed of metal; as a more specific example, similar to top plate 20, fin 94 is formed of metal containing aluminum.

[0084] The fin 94 has an upper end and a lower end that are opposite to each other in the z-axis direction. In this embodiment, the upper end of the fin 94 is thermally and mechanically connected to the lower surface 24 of the top plate 20. In this embodiment, the fin 94 is integrally formed with the top plate 20; in other words, the fin 94 protrudes integrally from the lower surface 24 of the top plate 20. In this embodiment, the fin 94 extends from the lower surface 24 of the top plate 20 toward the refrigerant flow section 92 in the negative z-axis direction. The lower end of the fin 94 in this embodiment is fixed to the bottom plate 64 by an adhesive 98. Furthermore, in this embodiment, the extending direction of the fin 94 is approximately perpendicular to the respective main surfaces of the top plate 20 and the bottom plate 64.

[0085] In this embodiment, the plurality of fins 94 are needle-shaped fins. Furthermore, the cross-sectional shape of each of the plurality of fins 94 parallel to the main surface of the top plate 20 in this embodiment is rectangular. Therefore, compared to the case where the cross-sectional shape of the fins is circular, the surface area of ​​the fins 94 in contact with the refrigerant can be increased, thereby improving heat dissipation efficiency.

[0086] Furthermore, multiple fins 94 can be arranged in the refrigerant flow section 92 such that when the refrigerant flows in the refrigerant flow section 92, none of the sides of the rectangle are orthogonal to the main flow direction of the refrigerant in the cooling region 95. In the example of this embodiment, the main flow direction of the refrigerant in the cooling region 95 is the x-axis direction. In this embodiment, multiple fins 94 are arranged in the refrigerant flow section 92 such that none of the sides of the rectangle are orthogonal to the x-axis direction. More specifically, in this embodiment, multiple fins 94 are arranged in the refrigerant flow section 92 such that none of the sides of the rectangle are orthogonal to the x-axis direction, and one diagonal is parallel to the y-axis direction while the other diagonal is parallel to the x-axis direction. Alternatively, multiple fins 94 can be arranged in the refrigerant flow section 92 such that none of the sides of the rectangle are orthogonal to the x-axis direction, and one diagonal is inclined relative to the y-axis direction while the other diagonal is inclined relative to the x-axis direction. Compared to the case where multiple fins are arranged in the refrigerant flow section 92 such that any side of the rectangle is orthogonal to the main flow direction, any of the above structures can reduce the flow rate loss of the refrigerant flowing in the refrigerant flow section 92 and improve heat dissipation efficiency.

[0087] Furthermore, the fin 94 of this embodiment has a rhomboid shape in its cross-section in the xy plane, and this rhomboid shape is longer in the direction of the short side 93 of the refrigerant flow section 92 than in the direction of the long side 96 of the refrigerant flow section 92. Additionally, of the pair of diagonals of the rhomboid, the diagonal parallel to the long side 96 is shorter than the diagonal parallel to the short side 93. The length of each side of the rhomboid cross-section of the fin 94 can be from 1.9 mm to 2.2 mm. Each corner of the rhomboid cross-section can have a rounded corner with a radius of curvature of 0.1 mm to 0.2 mm.

[0088] The cross-sectional shape of each of the multiple fins 94 can be polygonal, for example, square. In this case, one diagonal of the square can be arranged in the refrigerant flow section 92 such that one diagonal of the square is along the direction from the first refrigerant flow path 30-1 toward the second refrigerant flow path 30-2.

[0089] Alternatively, multiple fins 94 can be arranged to form a predetermined pattern in the xy plane of the refrigerant flow section 92. In this embodiment, the multiple fins 94 are as follows: Figure 5 The arrangement is staggered as shown. Multiple fins 94 can be arranged in a square pattern in the xy plane of the refrigerant flow section 92.

[0090] A reinforcing pin 97 is disposed in the refrigerant flow section 92 and extends to connect between the top plate 20 and the bottom plate 64. As an example, the reinforcing pin 97 is formed of metal; more specifically, like the top plate 20, the reinforcing pin 97 is formed of a metal containing aluminum. The reinforcing pin 97 may also be formed of a metal with a higher rigidity than the metal forming the top plate 20 and the fins 94.

[0091] The reinforcing pin 97 has an upper end and a lower end opposite to each other in the z-axis direction. The upper end of the reinforcing pin 97 is thermally and mechanically connected to the lower surface 24 of the top plate 20. In this embodiment, the reinforcing pin 97 is integrally formed with the top plate 20; in other words, the reinforcing pin 97 protrudes integrally from the lower surface 24 of the top plate 20. In this embodiment, the reinforcing pin 97 extends from the lower surface 24 of the top plate 20 toward the refrigerant flow section 92 in the negative z-axis direction. In this embodiment, the lower end of the reinforcing pin 97 is fixed to the bottom plate 64, for example, by an adhesive 98. Furthermore, in this embodiment, the extending direction of the reinforcing pin 97 is substantially perpendicular to the respective main surfaces of the top plate 20 and the bottom plate 64.

[0092] Multiple reinforcing pins 97 can be configured in the refrigerant flow section 92, and the density of the multiple reinforcing pins 97 is sparser than the density of the multiple fins 94 configured in the cooling region 95. For example... Figure 2 and Figure 5 As shown, six reinforcing pins 97 are disposed in the refrigerant flow section 92 of this embodiment.

[0093] In a plane parallel to the main surface of the top plate 20, the cross-sectional area of ​​the reinforcing pin 97 is smaller than the cross-sectional area of ​​at least one of the plurality of fins 94. As an example, in this plane, the cross-sectional area of ​​the reinforcing pin 97 is less than 50% of the cross-sectional area of ​​each of the plurality of fins 94, and as... Figure 5 As shown, the reinforcing pin 97 of this embodiment has a circular cross-sectional shape parallel to the main plane of the top plate 20. The diameter of this circular cross-section is preferably, for example, 1 to 1.5 mm.

[0094] Furthermore, in the reinforcing pin 97, the cross-sectional shape of the main surface parallel to the top plate 20 can be non-polygonal, for example, it can be elliptical, or it can be a shape obtained by chamfering the corners of a polygon. When the cross-section is elliptical, it is preferably with the major axis along the y-axis and the minor axis along the x-axis. In this case, the length of the major axis of the ellipse is preferably 1.1 mm, and the length of the minor axis is preferably 0.9 mm.

[0095] Here, in Figure 5 The diagram shows a centerline CL that passes through the center of the sidewall 36 in the x-axis direction and extends in the y-axis direction. In this embodiment, the center of the cooling region 95 extending in the y-axis direction in the x-axis direction coincides with this centerline CL.

[0096] In this embodiment, when viewed from above, a portion of the metal layer 85 of each circuit board 76 overlaps with the cooling region 95, and the remaining portion overlaps with a connected region of one of the first refrigerant flow paths 30-1 and 30-2. In other words, the metal layer 85 of each circuit board 76, i.e., each circuit board 76, is configured such that when viewed from above, it overlaps with the cooling region 95. Figure 5 The centerline CL shown is shifted in the x-axis direction. Reinforcing pin 97 is configured within this connected region.

[0097] like Figure 5 As shown, in this embodiment, any one of the metal layers 85 of the U-phase unit 70U, V-phase unit 70V, and W-phase unit 70W partially overlaps with the cooling region 95 and partially overlaps with the second refrigerant flow path 30-2 when viewed from above. All six reinforcing pins 97 in this embodiment are disposed in the second refrigerant flow path 30-2.

[0098] When viewed from above, at least a portion of the reinforcing pin 97 may overlap with the metal layer 85. When the metal layer 85 is rectangular when viewed from above, at least a portion of the reinforcing pin 97 may overlap with the corner of the rectangle of the metal layer 85 when viewed from above.

[0099] When viewed from above, a portion of the reinforcing pin 97 in this embodiment overlaps with the corner of the rectangle of the metal layer 85, while a portion of the reinforcing pin 97 does not overlap with the metal layer 85. More specifically, when viewed from above, a portion of the reinforcing pin 97 overlaps with the portion of the corner of the rectangle of the metal layer 85 furthest from the cooling region 95.

[0100] As a specific example, such as Figure 5 As shown, in top view, the two corners of the rectangle located on the positive side of the x-axis of each metal layer 85 partially overlap with the two reinforcing pins 97. More specifically, in top view, the metal layer 85 in this embodiment is an octagon with four corners of a quadrilateral chamfered by a C-shape. Two opposite sides of the quadrilateral are parallel to the y-axis, and the other two opposite sides are parallel to the x-axis. In this embodiment, in top view, the two reinforcing pins 97 that partially overlap with one metal layer 85 overlap with the intersection point of one side of the metal layer 85 parallel to the y-axis located on the side of the second refrigerant flow path 30-2 and the corner of the C-shaped chamfer. In top view, when the reinforcing pin 97 overlaps with this intersection point, the solder life of the solder 79 can be improved more effectively than when the reinforcing pin 97 overlaps with parts other than the intersection point on the corner of the C-shaped chamfer.

[0101] Furthermore, of the two reinforcing pins 97, the reinforcing pin 97 near the corner of the rectangular refrigerant flow section 92 when viewed from above is located between the corner of the rectangular refrigerant flow section 92 and the metal layer 85. More specifically, in this embodiment, when viewed from above, the two reinforcing pins 97 near the two inclined portions 37 located on the second refrigerant flow path 30-2 side of the refrigerant flow section 92 are located between the inclined portion 37 and the metal layer 85. Additionally, "between the corner of the rectangular refrigerant flow section 92 and the metal layer 85" refers to any position between the corner and the metal layer 85 on any straight line connecting the corner of the rectangular refrigerant flow section 92 and the metal layer 85 closest to that corner. When defined as "between the corner of the rectangular refrigerant flow section 92 and the metal layer 85," it may include the corner as one end of the range and the metal layer 85 as the other end of the range.

[0102] As described above, in the semiconductor module 100 according to this embodiment, in the cooling device 10 where the circuit board 76 of the semiconductor device 70 is fixed to the main surface of the top plate 20, the refrigerant flow section 92 for refrigerant flow includes a cooling region 95 with a plurality of fins 94, and a first refrigerant flow path 30-1 and a second refrigerant flow path 30-2 positioned such that the cooling region 95 is sandwiched between each other, and the plurality of fins 94 are not disposed in the aforementioned refrigerant flow paths. Furthermore, the first refrigerant flow path 30-1 is connected to an inlet 41 for introducing refrigerant into the refrigerant flow section 92, and the second refrigerant flow path 30-2 is connected to an outlet 42 for discharging refrigerant from the refrigerant flow section 92.

[0103] When multiple heat sources such as semiconductor chips 78 are present on the top plate 20 of the cooling device 10 in the y-axis direction, if the main flow direction of the refrigerant flowing through the cooling device 10 is parallel to the arrangement direction of the heat sources (y-axis direction), it is impossible to uniformly cool each heat source. The semiconductor module 100 of this embodiment has the following configuration structure: the main flow direction (positive x-axis direction) of the refrigerant flowing through the cooling device 10 is orthogonal to the arrangement direction (y-axis direction) of the multiple heat sources.

[0104] More specifically, in the semiconductor module 100 according to this embodiment, the refrigerant flow section 92 is a rectangle with a long side 96 and a short side 93 in a cross-section parallel to the main surface (in the xy plane) of the top plate 20. Refrigerant is introduced into the refrigerant flow section 92 from an inlet 41 communicating with one side in the direction of the short side 93 (x-axis direction), diffuses throughout the refrigerant flow section 92, and is discharged from an outlet 42 communicating with the other side in the direction of the short side 93 (x-axis direction). The refrigerant contacts the lower surface 24 and fins 94 of the top plate 20 on which the circuit board 76 is mounted to cool the individual semiconductor chips 78 of the semiconductor device 70. In other words, the heat generated by the individual semiconductor chips 78 moves to the refrigerant near the top plate 20 and fins 94.

[0105] Thus, according to the semiconductor module 100 of this embodiment, the cooling device 10 can effectively cool the heat generated by the individual semiconductor chips 78 arranged in the y-axis direction on the upper surface of the cooling device 10 by means of a refrigerant.

[0106] The inventors of this application conducted experiments on a semiconductor module that repeatedly changed temperature due to external environment and its own heat generation. In this semiconductor module, a cooler is mounted on the semiconductor device, and the cooler includes a finned region with heat sinks and two guide regions that clamp the finned region. However, there are no structures like heat sinks in the two guide regions, and when viewed from above, the circuit board of the semiconductor device is partially exposed from the finned region to the guide regions.

[0107] Experimental results show that large stresses and plastic strains are generated in the exposed portion of the solder layer between the metal layer on the lower surface of the insulating plate and the top plate of the cooling device in the circuit board. It has been found that the greatest stresses and plastic strains are generated in this solder, particularly on the inner side of the corner near the sidewall of the cooler when viewed from above. It can be considered that the top plate of the cooling device is prone to deformation in the guiding area, especially at this location, thus having an impact. Furthermore, it has been found that deformation of the top plate of the cooling device is locally suppressed in areas where structures such as the sidewall of the cooling device connect to the lower surface and have relatively high rigidity.

[0108] Furthermore, in the semiconductor module 100 of this embodiment, when viewed from above, a portion of the metal layer 85 of the circuit board 76 overlaps with the cooling region 95, and a portion of the metal layer 85 overlaps with the second refrigerant flow path 30-2. The aforementioned refrigerant flow section 92 also has a reinforcing pin 97, which extends to connect between the top plate 20 and the bottom plate 64 in the second refrigerant flow path 30-2.

[0109] In the semiconductor module 100, the semiconductor device 70 generates a maximum heat of approximately 170°C during use. On the other hand, the refrigerant flowing in the refrigerant circulation section 92 of the cooling device 10 is maintained at approximately room temperature to 70°C. As a result, a temperature difference of more than 100°C sometimes occurs between the semiconductor device 70 and the cooling device 10. Furthermore, this temperature difference can vary significantly depending on the ambient temperature at which the semiconductor module 100 is placed.

[0110] According to the semiconductor module 100 of this embodiment having the above-described structure, even when there is a large difference between the coefficient of linear expansion of, for example, the insulating plate 81 containing ceramic and the cooling device 10 containing, for example, aluminum, and under conditions of repeated temperature changes due to external environment and self-heating, the reinforcing pin 97 extending between the top plate 20 and the bottom plate 64 of the cooling device 10 can suppress large stress and plastic strain on the solder 79 present between the metal layer 85 provided on the lower surface of the insulating plate 81 and the top plate 20 of the cooling device 10. Therefore, the semiconductor module 100 can improve thermal cycling reliability and extend the lifespan of the solder 79.

[0111] Furthermore, in the semiconductor module 100 of this embodiment, in a plane parallel to the main surface of the top plate 20 of the cooling device 10, the cross-sectional area of ​​the reinforcing pin 97 is smaller than the cross-sectional area of ​​at least one of the plurality of fins 94. When the cross-sectional area of ​​the reinforcing pin 97 is larger than the cross-sectional area of ​​the fin 94, when the refrigerant introduced into the refrigerant flow section 92 of the cooling device 10 from the inlet 41 diffuses within the first refrigerant flow path 30-1 where the fins 94 are not located, although a flow rate loss occurs, this flow rate loss can be suppressed by the above structure. As a result, the reduction in the cooling efficiency of the cooling device 10 for the semiconductor device 70 can be suppressed.

[0112] In the above embodiments, the top plate 20, sidewall 36, and fins 94 forming the substrate 40 can be integrally formed. In this embodiment, the top plate 20, sidewall 36, and fins 94 can be integrally formed. For example, the top plate 20, sidewall 36, and fins 94 can be integrally formed from a single continuous plate member.

[0113] For example, the top plate 20, sidewall 36, and fins 94 can be integrally formed by stamping a continuous plate component using a die that corresponds to the shape of the top plate 20, sidewall 36, and fins 94. As other examples, the top plate 20, sidewall 36, and fins 94 can be integrally formed by using 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 reduces the number of components compared to fixing separately formed components together by integrally forming the top plate 20, sidewall 36, and fins 94.

[0114] Here, as Figure 4 As shown, the thickness of the cross-section of the top plate 20 in a plane orthogonal to the direction viewed from above (xz plane and yz plane) can be made thicker on the outer side of the side wall 36 than on the inner side of the side wall 36. In the cooling device 10 of this embodiment, the thickness T1 of the fastening part 21 can be made thicker than the thickness T2 of the cooling region 95 in the top plate 20.

[0115] By reducing the thickness of the cooling region 95 in the top plate 20, heat from the semiconductor device 70 disposed on the upper surface 22 of the top plate 20 can be efficiently transferred to the refrigerant flowing in the refrigerant circulation 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 securely fastened to an external device with bolts or the like can be suppressed.

[0116] Furthermore, the thickness T3 of the sidewall 36 can be made thicker than the thickness T2 of the cooling region 95 in the top plate 20. By thinning the cooling region 95 in the top plate 20, the 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 cooling region 95 in the top plate 20 can be suppressed. As a result, in the semiconductor module 100, large stresses and plastic strains can be suppressed at the solder 79 where the semiconductor device 70 is fixed to the top plate 20.

[0117] Furthermore, the thickness T4 of the base plate 64 can be thicker than either the thickness T2 of at least the cooling region 95 of the top plate 20 or the thickness T3 of the side wall 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 side wall 36 by forging, or it can be formed by fastening the flange portion of the side wall 36, which is formed by stamping, to the top plate 20.

[0118] Figures 6 to 10 The figures show modified examples of the configuration relationships of the metal layer 85 of the semiconductor device 70, the cooling region 95 of the cooling device 10, and the reinforcing pin 97 in a semiconductor module 100 according to an embodiment of the present invention.

[0119] Figures 6-10 The figure shows the sidewall 36, bottom plate 64, inlet 41 and outlet 42 of the cooling device 10 in the semiconductor module 100, the metal layer 85 of each of the U phase unit 70U, V phase unit 70V and W phase unit 70W, multiple fins 94 and cooling area 95, and reinforcing pin 97. For clarity, illustrations of other structures in the semiconductor module 100 are omitted.

[0120] also, Figures 6-10 In the variant example shown, with the use of Figures 1-5 Compared to the semiconductor module 100 in the illustrated embodiment, the only differences are in the configuration, quantity, and / or size of specific structures; the functions and uses are the same. Therefore, for Figures 6-10 The various structures shown in the modified examples, their use and utilization Figures 1-10 Reference numbers are used for the same structures in the embodiments described, and repeated descriptions are omitted.

[0121] exist Figure 6 , Figure 8 and Figure 9 In the variant example shown, with... Figures 1-5 The implementation method described is different, with the center of each circuit board 76 in the x-axis direction located on the center line CL. Furthermore, when viewed from above, a portion of the metal layer 85 of each circuit board 76 overlaps with the cooling region 95, and a portion overlaps with both the first refrigerant flow path 30-1 and the second refrigerant flow path 30-2.

[0122] exist Figure 6In the illustrated variation, twelve reinforcing pins 97 are disposed in the refrigerant flow section 92. When viewed from above, a portion of each reinforcing pin 97 overlaps with a corner of the rectangle of the metal layer 85, while a portion does not overlap with the metal layer 85. In other words, in each of the three metal layers 85 of the semiconductor device 70 of the semiconductor module 100, when viewed from above, one reinforcing pin 97 overlaps with each of the four corners of the rectangle of the metal layer 85. More specifically, in this embodiment, when viewed from above, the four reinforcing pins 97 that partially overlap with one metal layer 85 overlap with the intersection of the two sides parallel to the y-axis of the metal layer 85 and the corner of the C-shaped chamfer. Furthermore, in this embodiment, when viewed from above, the four reinforcing pins 97 located near the four inclined portions 37 are respectively situated between the inclined portions 37 and the metal layer 85. Even using the semiconductor module 100 involved in this variation, the same effect as described above can be achieved.

[0123] Figure 7 In the variant example shown, with Figures 1-5 Similarly, in the embodiment shown, six reinforcing pins 97 are disposed in the refrigerant flow section 92. Furthermore, in this variation, with... Figures 1-5 Similarly, in the illustrated embodiment, when viewed from above, a portion of the metal layer 85 of each circuit board 76 overlaps with the cooling region 95, and the remaining portion overlaps with a connected region of one of the first coolant flow paths 30-1 and the second coolant flow path 30-2. In other words, the metal layer 85 of each circuit board 76, i.e., each circuit board 76, is configured such that, when viewed from above, it overlaps with the cooling region 95. Figure 7 The centerline CL shown is shifted in the x-axis direction. Reinforcing pin 97 is configured within this connected region.

[0124] As with Figures 1-5 The difference in the illustrated embodiment is that, in this variation, when viewed from above, none of the reinforcing pins 97 overlap with the metal layer 85 and are located near the corners of the rectangle of the metal layer 85. In other words, in each of the three metal layers 85 provided in the semiconductor device 70 of the semiconductor module 100, when viewed from above, a reinforcing pin 97 is disposed slightly outward at each of the four corners of the rectangle of the metal layer 85. Furthermore, the vicinity of the corner can be any position within a circular area centered on the corner, within a region that does not overlap with the metal layer 85 when viewed from above. Additionally, the vicinity of the corner can be a position away from the corner in the x-axis direction, a position away from the corner in the y-axis direction, or a position away from the corner in both the x-axis and y-axis directions, within a region that does not overlap with the metal layer 85 when viewed from above.

[0125] Preferably, in top view, the reinforcing pin 97 can be located at a predetermined distance from the corner of the rectangle of the metal layer 85 furthest from the cooling region 95. An example of this distance is a distance greater than 0 mm and less than 2 mm along the direction away from the cooling region 95. As an example, the direction away from the cooling region 95 referred to here is the direction perpendicular to one of the four sides of the rectangular cooling region 95 adjacent to a refrigerant flow path 30 in top view, and is the direction away from the cooling region 95. In this embodiment, this direction is the positive x-axis direction. Additionally, in Figure 8 The same applies to the variations shown; repeated explanations are omitted.

[0126] In addition, such as Figure 7 As shown, for each of the two metal layers 85 located at both ends in the y-axis direction, when viewed from above, two reinforcing pins 97 located near the two corners of the sidewall element 36S near the sidewall 36 in the rectangle of the metal layer 85 are located between the corners of the rectangle of the refrigerant flow section 92 and the metal layer 85. More specifically, in this embodiment, when viewed from above, four reinforcing pins 97 near the four inclined portions 37 are respectively located between the inclined portion 37 and the metal layer 85. Even when using the semiconductor module 100 involved in this variation, the same effect as described above can be achieved.

[0127] exist Figure 8 In the variant example shown, with Figure 6 Similarly, in the modified example shown, twelve reinforcing pins 97 are arranged in the refrigerant flow section 92. As with... Figure 6 The differences between the variant examples shown and Figure 7 Similarly, in the modified example shown, when viewed from above, none of the reinforcing pins 97 overlap with the metal layer 85, and they are located near the corners of the rectangle of the metal layer 85. Furthermore, as... Figure 8 As shown, for each of the two metal layers 85 located at both ends in the y-axis direction, four reinforcing pins 97 located near the two corners of the sidewall element 36S close to the sidewall 36 in the rectangle of the metal layer 85 when viewed from above are located between the corners of the rectangle of the refrigerant flow section 92 and the metal layer 85 when viewed from above. Even using the semiconductor module 100 involved in this variation, the same effect as described above can be achieved.

[0128] exist Figure 9 In the modified example shown, eight reinforcing pins 97 are arranged in the refrigerant flow section 92, and... Figure 8 Similarly, in the modified example shown, any reinforcing pin 97 does not overlap with the metal layer 85 when viewed from above, and is located near the corner of the rectangle of the metal layer 85. Furthermore, as... Figure 9As shown, for each of the two metal layers 85 located at both ends in the y-axis direction, four reinforcing pins 97 located near the two corners of the sidewall element 36S of the rectangle of the metal layer 85 near the sidewall 36 when viewed from above are located between the corners of the rectangle of the refrigerant flow section 92 and the metal layer 85 when viewed from above.

[0129] As with Figure 8 The difference in the illustrated variation is that, in this variation, when viewed from above, only one reinforcing pin 97 is disposed between the corners of the rectangles of two adjacent metal layers 85. In other words, in this variation, the reinforcing pins 97 that should be located near the corners of each metal layer 85 are merged into one between two opposite corners of adjacent metal layers 85, for example, at the middle position.

[0130] Furthermore, in this variant example, with Figure 8 Similarly, in the variation shown, the reinforcing pin 97, when viewed from above, is located at a predetermined distance from the portion of the rectangle of the metal layer 85 furthest from the cooling area 95, which, as an example, is a distance greater than 0 mm and less than 2 mm along the direction away from the cooling area 95. As with... Figure 8 The difference in the illustrated variation is that, in this variation, the direction away from the cooling region 95 is inclined relative to both the x-axis and y-axis directions. Figure 10 The same applies to the variant shown, and repeated descriptions are omitted. Even using the semiconductor module 100 involved in this variant, the same effect as described above can be achieved.

[0131] exist Figure 10 In the modified example shown, four reinforcing pins 97 are arranged in the refrigerant flow section 92, and... Figure 9 Similarly, in the variant shown, any reinforcing pin 97 does not overlap with the metal layer 85 when viewed from above, and is located near the corner of the rectangle of the metal layer 85. Furthermore, with... Figure 9 Similarly, in the modified example shown, when viewed from above, only one reinforcing pin 97 is positioned between the corners of the rectangles of two adjacent metal layers 85. That is, when viewed from above, two reinforcing pins 97 are positioned one by one between the corner of the rectangle of the metal layer 85 located on the most negative side in the y-axis direction and the corner of the rectangle of the metal layer 85 adjacent to that metal layer 85, and the remaining two reinforcing pins 97 are positioned one by one between the corner of the rectangle of the metal layer 85 located on the most positive side in the y-axis direction and the corner of the rectangle of the metal layer 85 adjacent to that metal layer 85.

[0132] As with Figure 9 The difference in the modified example shown is that, in this modified example, the metal layer 85 of each circuit board 76, i.e., each circuit board 76, is configured such that, when viewed from above, it is positioned relative to... Figure 10The centerline CL shown is shifted in the x-axis direction. However, in this modified example, it is... Figure 9 Similarly, in the modified example shown, when viewed from above, a portion of the metal layer 85 of each circuit board 76 overlaps with the cooling region 95, and a portion overlaps with both the first refrigerant flow path 30-1 and the second refrigerant flow path 30-2.

[0133] In addition, Figure 10 In the modified example shown, when viewed from above, a corner of the metal layer 85 of the circuit board 76 located at both ends in the y-axis direction partially overlaps with the inclined portion 37 of the sidewall 36. For example, when viewed from above, the metal layer 85 is rectangular, and the corner of the metal layer 85 may partially overlap with the inclined portion 37.

[0134] More specifically, only one corner of the metal layer 85 of the circuit board 76 of each of the three units, U-phase unit 70U and 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.

[0135] Instead, preferably, when viewed from above, 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 side of the y-axis, can each partially overlap with the two inclined portions 37 of the sidewall 36 on the negative side of the y-axis. Similarly, the two corners of the metal layer 85 of the W-phase unit 70W, located on the positive side of the y-axis, can each partially overlap with the two inclined portions 37 of the sidewall 36 on the positive side of the y-axis.

[0136] The metal layer 85, when viewed from above, is 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.

[0137] When 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 10As shown, in this example, when viewed from above, the corner of the metal layer 85 of the U-phase unit 70U located on the negative y-axis side, specifically the corner on the positive x-axis side, can be 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 corner of the metal layer 85 of the W-phase unit 70W located on the positive y-axis side, specifically the corner on the positive x-axis side, can be located between the inner and outer sides of the two inclined portions 37 on the positive y-axis side of the sidewall 36.

[0138] 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 10 As shown, in this example, when viewed from above, the portion of the metal layer 85 of the U-phase unit 70U, excluding the corner of the square on the x-axis among the two corners located 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 corner on the positive x-axis among the two corners located on the positive y-axis side, may not overlap with the sidewall 36. Even using the semiconductor module 100 involved in this modified example, the same effect as described above can be achieved.

[0139] Figure 11 This is a schematic diagram illustrating a vehicle 200 according to one embodiment of the present invention. The vehicle 200 is a vehicle that uses electricity to generate at least a portion of its propulsion. As an example, the vehicle 200 is an electric vehicle that uses an electric drive device such as an electric motor to generate all of its propulsion, or a hybrid vehicle that uses an electric drive device such as an electric motor in combination with an internal combustion engine driven by fuel such as gasoline.

[0140] The vehicle 200 includes a control device 210 (external device) for controlling electrically driven 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 electrically driven equipment.

[0141] Figure 12 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 having output terminals U, V and W, and can be part of an on-board unit that drives a vehicle's electric motor.

[0142] 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.

[0143] Each semiconductor chip 78-1 to 78-6 can alternately switch on and off according to the signal input to the corresponding control terminal. In this embodiment, 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 other input terminals N1, N2, and N3 can also be electrically connected to each other.

[0144] 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.

[0145] In the description of the above embodiments, for example, the word "approximately" is sometimes used together to express a specific state, such as "approximately orthogonal", "approximately the same", "approximately consistent", "approximately constant", "approximately symmetrical", "approximately rhomboid", "approximately rectangular", etc. 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.

[0146] 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. Those skilled in the art will recognize that various changes or improvements can be made to the above embodiments. As can be seen from the claims, such changes or improvements are also included within the technical scope of the present invention.

[0147] For example, in the above embodiment, 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.

[0148] Additionally, for example, the fins 94 can be configured in a grid pattern, preferably in a diagonal grid pattern or a diamond grid pattern. Additionally, for example, the inlet 41 and outlet 42 can be adjacent to the fin region 95 in the refrigerant flow section 92 and arranged diagonally. Additionally, for example, in a top view, the length of the long side 96 of the openings of the inlet 41 and outlet 42 can be greater than the length of the short side 93.

[0149] For example, in the above embodiment, a structure in which the top plate 20, sidewall 36, and fins 94 are integrally formed in the substrate 40 has been described. However, instead, the top plate 20, sidewall 36, and fins 94 can also be formed separately and then fixed to each other using an adhesive 98 or the like. Alternatively, the top plate 20 and sidewall 36 can be integrally formed, while the separately formed fins 94 can be fixed to the top plate 20. Alternatively, the top plate 20 and fins 94 can be integrally formed, while the separately formed sidewall 36 can be fixed to the top plate 20 using an adhesive 98 or the like. Furthermore, the sidewall 36 and bottom plate 64 can be integrally formed, for example, by stretching, while the separately formed top plate 20 can be fixed to the sidewall 36 using an adhesive 98 or the like, for example, by brazing. In this case, the sidewall 36 can extend along the xy plane to the area where the fastening portion 21 of the top plate 20 is located, and connect the extended surface of the sidewall 36 to the lower surface 24 of the top plate 20.

[0150] Alternatively, for example, in the above embodiment, a structure in which the fin 94 is integrally formed with the top plate 20 and extends toward the bottom plate 64 has been described. However, instead, the 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 fin 94 can be fixed to the top plate 20 using an adhesive 98 or the like.

[0151] Furthermore, for example, in the above embodiment, a structure in which the fin 94 extends perpendicularly to the top plate 20 and the bottom plate 64 along the normal direction of the main surface of the top plate 20 is described. However, instead, the fin 94 may also extend at an angle relative 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 dimension of the fin 94 in the xy plane may be constant or variable in the z-axis direction. As a more specific example, it may extend from either the top plate 20 or the bottom plate 64 in a manner where the fin becomes thinner towards the front end.

[0152] Furthermore, for example, in the above embodiments, the plurality of fins 94 are described as needle-shaped fins, but instead, they can be plate-shaped blade-type fins, for example, the cross-sectional shape parallel to the main surface of the top plate 20 can be an elongated rectangle.

[0153] Alternatively, 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 wall 36. In this case, the inlet 41 and the outlet 42 may be formed on two opposite sides of the side wall 36 along the x-axis.

[0154] Furthermore, in the above embodiment, the inner side of the sidewall 36 was described as a straight line when viewed from above, but it is not limited to a straight line; it could also be a broken line or a curve. For example, when viewed from above, the inner side of the sidewall 36, etc., could be a curve that expands into an arc shape on one side of the refrigerant flow section 92, or it could be a curve that is concave into an arc shape on the opposite side.

[0155] 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 as long as the output of the preceding process is not used for the subsequent process. The use of terms such as "firstly" and "nextly" 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 this order.

[0156] Label Explanation

[0157] 10 Cooling device, 20 Top plate, 21 Fastening part, 22 Upper surface, 24 Lower surface, 30 Refrigerant flow path, 30-1 First refrigerant flow path, 30-2 Second refrigerant flow path, 36, 38, 39 Side walls, 36S, 36L, 38S, 38L, 39S, 39L Side wall elements, 37, 37S, 37L Inclined parts, 40 Substrate, 41 Inlet, 42 Outlet, 64 Base plate, 70 Semiconductor device, 70U U-phase unit, 70V V-phase unit, 70W W-phase unit, 71 resin structure, 72 housing, 74 sealing part, 76 circuit board, 78 semiconductor chip, 79 solder, 80 through hole, 81 insulating plate, 83 circuit layer, 85, 86, 87, 88, 89, 90 metal layers, 92 refrigerant flow section, 93 short side, 96 long side, 94 fins, 95 cooling area, 97 reinforcing pin, 98 adhesive, 100 semiconductor module, 200 vehicle, 210 control device.

Claims

1. A semiconductor module, The semiconductor module includes a semiconductor device and a cooling device, characterized in that, The semiconductor device includes a semiconductor chip, a circuit board on which the semiconductor chip is mounted, and a resin structure that seals the semiconductor chip. The cooling device has: A top plate, the main surface of which is fixed the circuit board of the semiconductor device and the resin structure; A sidewall that is connected to the top plate; A base plate, which is connected to the side wall and opposite to the top plate; A refrigerant flow section, defined by the top plate, the side wall and the bottom plate, for allowing refrigerant to flow; An inlet for introducing refrigerant into the refrigerant flow section; An outlet, used to discharge refrigerant from the refrigerant flow section; as well as Multiple fins and reinforcing pins are disposed in the refrigerant flow section and extend to connect the top plate and the bottom plate. The refrigerant flow section includes: A cooling zone, wherein the cooling zone is configured with a plurality of the aforementioned fins; A first connecting region, which is adjacent to one side of the cooling region, connects to the inlet, and is not configured with the plurality of the fins; and The second connecting region, which is adjacent to the opposite side of the cooling region (i.e., the other side), connects to the outlet and is not equipped with the multiple fins. The circuit board is a 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. When viewed from above, a portion of the metal layer overlaps with the cooling region, and the remaining portion overlaps with one of the connected regions of the first and second connected regions. The reinforcing pin is disposed in the one connected area. In a plane parallel to the main surface of the top plate, the cross-sectional area of ​​the reinforcing pin is smaller than the cross-sectional area of ​​at least one of the plurality of fins.

2. The semiconductor module as described in claim 1, characterized in that, When viewed from above, at least a portion of the reinforcing pin overlaps with the metal layer.

3. The semiconductor module as described in claim 2, characterized in that, When viewed from above, the metal layer appears rectangular. When viewed from above, at least a portion of the reinforcing pin overlaps with the corner of the rectangle of the metal layer.

4. The semiconductor module as described in claim 3, characterized in that, When viewed from above, a portion of the reinforcing pin overlaps with the corner of the rectangle of the metal layer, and the portion other than the aforementioned portion does not overlap with the metal layer.

5. The semiconductor module as described in claim 3 or 4, characterized in that, When viewed from above, at least a portion of the reinforcing pin overlaps with the portion of the corner of the rectangle of the metal layer furthest from the cooling area.

6. The semiconductor module as described in claim 1, characterized in that, When viewed from above, the metal layer appears rectangular. When viewed from above, the reinforcing pin does not overlap with the metal layer, and the reinforcing pin is located near the corner of the rectangle of the metal layer.

7. The semiconductor module as described in claim 6, characterized in that, When viewed from above, the reinforcing pin is positioned at a distance greater than 0 mm and less than 2 mm from the portion of the rectangular corner of the metal layer furthest from the cooling area, along a direction away from the cooling area.

8. The semiconductor module as described in claim 6 or 7, characterized in that, The semiconductor device comprises two or more of the aforementioned circuit boards. When viewed from above, only one reinforcing pin is disposed between the corners of the rectangles of two adjacent metal layers.

9. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The refrigerant flow section is rectangular when viewed from above. When viewed from above, the reinforcing pin is located between the corner of the rectangle of the refrigerant flow section and the metal layer.

10. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The cross-section of the reinforcing pin, parallel to the main surface of the top plate, is circular.

11. The semiconductor module as claimed in claim 10, characterized in that, The cross-sectional shape of each of the plurality of fins parallel to the main surface of the top plate is rectangular. The plurality of fins are arranged in the refrigerant flow section such that when the refrigerant flows in the refrigerant flow section, neither side of the rectangle is orthogonal to the main flow direction of the refrigerant in the cooling area.

12. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The cross-section of the reinforcing pin, parallel to the main surface of the top plate, is non-polygonal. The cross-sections of the multiple fins, which are parallel to the main surface of the top plate, are polygonal in shape.

13. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The density of the plurality of reinforcing pins disposed in at least one of the communicating regions is sparser than the density of the plurality of fins disposed in the cooling region.

14. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The insulating plate contains ceramic. The metal layer is fixed to the main surface of the top plate by solder.

15. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The resin structure includes a sealing portion that seals the semiconductor chip and a receiving portion that surrounds the sealing portion. The storage section is fixed to the main surface of the top plate by an adhesive.

16. A vehicle, characterized in that, The semiconductor module comprising any one of claims 1 to 15.

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