Semiconductor module

Abstract

A semiconductor module capable of reducing a flow rate distribution of a refrigerant in a cooling device is provided. The semiconductor module has the cooling device, wherein the cooling device has: a top plate; a side wall connected to the top plate; a bottom plate facing the top plate and connected to the side wall; a plurality of polygonal pin fins (94) having one end connected to a rectangular fin area (95) of a surface of the top plate facing the bottom plate and separated from the side wall, and arranged in a matrix shape when viewed from above; an inlet (41) of the refrigerant, a center of a flow path of the refrigerant at the inlet being arranged at a position (Pi) close to a part of one long side of the fin area (95) when viewed from above; and an outlet (42) of the refrigerant, a center of a flow path of the refrigerant at the outlet being arranged at a position (Po) close to a part of the other long side of the fin area (95) when viewed from above, wherein a matrix direction of the plurality of pin fins (94) forms an angle with respect to a straight line (IO) connecting the position (Pi) and the position (Po), and a length (L1) of a line segment of the straight line (IO) crossing the fin area (95) is longer than a length (L2) of a short side of the fin area (95).

Description

Technical Field

[0001] This invention relates to a semiconductor module. Background Technology

[0002] Previously, a semiconductor module having a cooling device including cooling pins was known (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2012 / 157247 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the aforementioned semiconductor module, the refrigerant flow rate distribution in the cooling device is not sufficiently small.

[0008] Solution for solving the problem

[0009] To address the aforementioned problems, the present invention provides a semiconductor module comprising a cooling device, wherein the cooling device comprises: a top plate; a sidewall connected to the top plate; a bottom plate facing the top plate and connected to the sidewall; a plurality of polygonal fins, one end of which is connected to a rectangular fin region separated from the sidewall on the surface of the top plate facing the bottom plate, and arranged in a matrix configuration when viewed from above; a refrigerant inlet, wherein the center of the flow path of the refrigerant at the inlet is positioned close to a portion of one long side of the fin region when viewed from above; and a refrigerant outlet, wherein the center of the flow path of the refrigerant at the outlet is positioned close to a portion of another long side of the fin region when viewed from above, wherein the matrix direction of the plurality of fins forms an angle with respect to a straight line connecting the inlet and outlet positions, and the length of the segment of the straight line traversing the fin region is longer than the length of the short side of the fin region. Attached Figure Description

[0010] Figure 1 This is a schematic perspective view illustrating an example of a semiconductor module 100 according to one embodiment of the present invention.

[0011] 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.

[0012] 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.

[0013] Figure 4This is a diagram illustrating an example of the configuration of the fin region 95 and components 70U, 70V, 70W of the cooling device 10 in a semiconductor module 100 according to an embodiment of the present invention, the shape of the needle fin 94, and the flow direction of the refrigerant.

[0014] Figure 5 This is a diagram showing an example of the configuration of the fin zone 95, inlet 41, outlet 42, and needle fin 94 in the cooling device 10.

[0015] Figure 6 This is a diagram showing an example of the configuration of the fin zone 95, inlet 41, outlet 42, and needle fin 94 in the cooling device 10.

[0016] Figure 7 This is a reference example diagram showing the configuration of the fin area 95, inlet 41, outlet 42, and needle fin 94 in the cooling device 10.

[0017] Figure 8 It is a graph showing the relationship between the angle θ1 (degrees) formed by the straight line IO and the mainstream direction MS and the refrigerant flow rate.

[0018] Figure 9 This is a diagram showing a modified example of the configuration of the fin area 95, inlet 41, outlet 42, and needle fin 94 in the cooling device 10.

[0019] Figure 10 This is an enlarged view of Needlewing 94.

[0020] Figure 11 This is an enlarged view of the needle-wing 94 from other examples.

[0021] Figure 12 yes Figure 3 A magnified view of region A in the image.

[0022] Figure 13 This is a diagram illustrating a schematic representation of a vehicle 200 according to one embodiment of the present invention.

[0023] Figure 14 This is a main circuit diagram of a semiconductor module 100 according to one embodiment of the present invention. Detailed Implementation

[0024] The present invention will now be described through embodiments, but these embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessary for the solution of the invention.

[0025] 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 2This is a schematic perspective view showing an example of the cooling device 10 of the semiconductor module 100. Additionally, 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 This is a diagram illustrating an example of the arrangement of the fins 95 of the cooling device 10 and the semiconductor device 70, the shape of the pin fins 94, and the flow direction of the refrigerant in a semiconductor module 100 according to an embodiment of the present invention. Figure 3 The diagram shows a virtual cut using the xz plane. Figure 1 The semiconductor chip 78 of the U-phase component 70U in the semiconductor module 100 shown, and Figure 2 The state of the outlet 42 of the cooling device 10 shown. Figure 4 In the middle, it is shown by dashed lines. Figure 1 The U-phase assembly 70U, V-phase assembly 70V, and W-phase assembly 70W are shown. In addition, Figure 3 The area [A] indicated by the dashed line will be discussed later. Figure 12 The area shown in the enlarged view.

[0026] like Figures 1-4 As shown, the semiconductor module 100 includes a cooling device 10. In this example, the cooling device 10 houses the semiconductor device 70. In this embodiment, the surface of the cooling device 10 housing the semiconductor device 70 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 to the semiconductor device 70 in the z-axis direction is referred to as "up," and the opposite direction is referred to as "down," but the up and down directions are not limited to the direction of gravity. Furthermore, in this embodiment, the upper surface of each component is referred to as the upper surface, the lower surface as the lower surface, and the surface between the upper and lower surfaces as the side surface. In this embodiment, a top view refers to the view of the semiconductor module 100 from the positive z-axis direction.

[0027] The semiconductor device 70 includes semiconductor chips 78 and circuit boards 76 for mounting the semiconductor chips 78. In this example, the semiconductor device 70 may include three circuit boards 76, each of which may mount two semiconductor chips 78. The semiconductor device 70 in this example may be a power semiconductor device, including a U-phase assembly 70U comprising circuit boards 76, semiconductor chips 78-1 and 78-4, a V-phase assembly 70V comprising circuit boards 76, semiconductor chips 78-2 and 78-5, and a W-phase assembly 70W comprising circuit boards 76, semiconductor chips 78-3 and 78-6. The semiconductor module 100 in this example may also function as a device constituting a three-phase AC inverter. Furthermore, each semiconductor chip 78 in the U-phase assembly 70U, V-phase assembly 70V, and W-phase assembly 70W becomes a heat source when the semiconductor module 100 is in operation.

[0028] 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 may have components such as an insulated-gate bipolar transistor (IGBT), a MOSFET, and a freewheeling diode (FWD) formed on a semiconductor substrate such as silicon. Semiconductor chip 78 may also be a reverse-conducting 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.

[0029] The lower surface electrode of the semiconductor chip 78 is connected to the upper surface of the circuit substrate 76. 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 also be silicon carbide (SiC) or gallium nitride (GaN).

[0030] The semiconductor chip 78, including switching elements such as IGBTs and MOSFETs, has control electrodes. The semiconductor module 100 may also 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.

[0031] As an example, the circuit board 76 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 of the insulating plate, and a metal layer disposed on the lower surface. The circuit board 76 has an upper surface and a lower surface, and the lower surface of the circuit board 76 is disposed on the upper surface of the cooling device 10. As an example, the circuit board 76 is fixed to the upper surface of the cooling device 10 via the metal layer by solder or the like. Furthermore, as an example, two semiconductor chips 78 are fixed to the upper surface of the circuit board 76 via the circuit layer.

[0032] The circuit board 76 can be, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazing) substrate. The insulating plate can be formed using ceramic materials such as alumina (Al2O3), aluminum nitride (AlN), or silicon nitride (Si3N4). The circuit layer and metal layer can be substrates containing conductive materials such as copper or copper alloys. The circuit layer is fixed to the upper surface of the insulating plate by soldering, brazing, or the like. The semiconductor chip 78 is electrically and mechanically connected to the upper surface of the circuit layer by soldering or the like; that is, it is directly connected to the upper surface of the circuit layer in an electrical circuit manner. Furthermore, the semiconductor chip 78 and the circuit layer can also be electrically connected to other conductive components such as main terminals via leads or the like.

[0033] The cooling device 10 has a base plate 40 and a bottom plate 64. The base plate 40 includes a top plate 20 for mounting a semiconductor device 70, a sidewall 36 connected to the top plate 20, and a plurality of pins 94 connected to the top plate 20. One end of each of the plurality of pins 94 is connected to a rectangular fin region 95 separated from the sidewall 36 on the surface of the top plate 20 facing the bottom plate 64. The plurality of pins 94 are arranged in a matrix when viewed from above.

[0034] The top plate 20 is a plate-shaped component with a main surface extending in the xy-plane. In this example, the top plate 20 is generally rectangular in plan view, having 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 the long side is parallel to the y-axis. The top plate 20 includes a fastening part 21 for fastening to an external device that mounts the semiconductor module 100. In plan view, the fastening part 21 is located further outward than the side wall 36 connected to the top plate 20 and has through holes 80 for inserting bolts, etc., of the external device. In this example, the fastening part 21 has four through holes 80, one at each of the four corners of the generally rectangular top plate 20.

[0035] 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. Since the sidewall 36 forms the side of the cooling device 10, when viewed from above, 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 this example, the sidewall 36 is located further inward than the fastening part 21 of the top plate 20 when viewed from above, and this sidewall 36 extends from the top plate 20 in the negative z-axis direction.

[0036] Multiple needle fins 94 are provided in fin area 95. The flow path of the refrigerant is defined by the arrangement of the needle fins 94. The cross-sectional shape of the needle fins 94 in the xy plane is substantially rhomboid. In the following description, one or more needle fins 94 are sometimes referred to simply as needle fins 94. The needle fins 94 extend from the top plate 20 in the negative z-axis direction. When viewed from above, the needle fins 94 are located further inward than the sidewalls 36 and are surrounded by the sidewalls 36. Multiple needle fins 94 can be arranged at equal intervals in fin area 95. The interval between the needle fins 94 can be, for example, more than 0.6 mm and less than 2.0 mm.

[0037] exist Figure 2 In the cooling device 10, for simplicity, the needle fins 94 are not shown in the diagram, but the area where the needle fins 94 are located, i.e., the fin area 95, is represented by dots. The fin area 95 can be rectangular when viewed from above, and its short side can be parallel to the x-axis and its long side can be parallel to the y-axis.

[0038] In the base plate 40 of this example, the top plate 20, sidewall 36, and pin fin 94 are integrally formed. For example, the top plate 20, sidewall 36, and pin fin 94 may also be integrally formed from a single continuous plate member. For example, the top plate 20, sidewall 36, and pin fin 94 may be integrally formed by punching a single continuous plate member using a die that corresponds to the shape of the top plate 20, sidewall 36, and pin fin 94. As another example, the top plate 20, sidewall 36, and pin fin 94 may be integrally formed by molding using any forging method such as cold forging at room temperature, warm forging at high temperature, hot forging, or melt forging using an impact press, or by molding based on forging. By integrally forming the top plate 20, sidewall 36, and pin fin 94, the semiconductor module 100 of this embodiment can reduce the number of components compared to fixing separately formed components together.

[0039] The base plate 64 is a plate-shaped component. In this example, the base plate 64 is approximately rectangular with a long side and a short side when viewed from above. Furthermore, in this example, the short side of the base plate 64 is parallel to the x-axis, and the 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.

[0040] The refrigerant flow section 92 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 configured to surround the refrigerant flow section 92 in the xy plane, and the top plate 20 and bottom plate 64 are configured to face each other in the z-axis direction, sandwiching the refrigerant flow section 92 between them. Therefore, the outline of the refrigerant flow section 92 in the xy plane is defined by the inner periphery of the side walls 36, and the refrigerant flow section 92 has a generally rectangular shape with a long side and a short side in the xy plane.

[0041] In addition, in this example, the base plate 64 has a through hole, i.e., an inlet 41, for introducing refrigerant into the refrigerant flow section 92, and a through hole, i.e., an outlet 42, for discharging refrigerant from the refrigerant flow section 92. Furthermore, the inlet 41 and outlet 42 may not be provided on the base plate 64. For example, the inlet 41 and outlet 42 may also be provided on the side wall 36 of the base plate 40. Additionally, as an example, the base plate 64 in this example may have a step portion 65 on the side facing the top plate 20 for determining the position of the fixed side wall 36. In plan view, the outline of the step portion 65 in this example may be smaller than the outline of the base plate 64, and may be approximately rectangular with a long side and a short side, similar to the base plate 64. Furthermore, the step portion 65 in this example may have its short side parallel to the x-axis and its long side parallel to the y-axis. Furthermore, the base plate 64 may also have other arbitrary steps capable of determining the position of the fixed side wall 36 instead. Figures 2 to 4 The step portion 65 is shown in the diagram. Alternatively, the base plate 64 may not have the step portion 65.

[0042] Inlet 41 and outlet 42 can be connected to pipes communicating 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 receive refrigerant through inlet 41 via one pipe, and the refrigerant can circulate within the refrigerant circulation section 92 before exiting through outlet 42 to another pipe. The base plate 64 and the refrigerant supply source can also be connected via sealing material disposed around inlet 41 and outlet 42.

[0043] 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 is approximately rectangular in the xy plane, along its diagonal direction. In top view, inlet 41 and outlet 42 can be located at the first header 30-1 and the second header 30-2, respectively. Inlet 41 and outlet 42 can be located at positions Pi and Po on the outer side of the fin area 95, respectively. Outlet 42 can be located on the opposite side of the fin area 95 relative to inlet 41 and separated from inlet 41 in the long side direction of the fin area. The length L1 of the line segment L1 of the straight line IO connecting positions Pi and Po, which traverses the fin region 95, is longer than the length L2 of the shorter side 93 of the fin region 95. The straight line IO can form an angle of 30° to 60° relative to the shorter side of the fin region 95, preferably substantially 45°. The inlet 41 and outlet 42 can have circular, arcuate rectangular, or elliptical openings when viewed from above. Positions Pi and Po are defined by the centers of the openings of inlet 41 and outlet 42, respectively. The center of the flow path at inlet 41 is located at position Pi, which is close to a portion of one long side 96 of the fin region 95 when viewed from above. The center of the flow path at outlet 42 is located at position Po, which is close to a portion of the other long side 96 of the fin region 95 when viewed from above.

[0044] In this embodiment, the semiconductor module 100 efficiently cools the heat generated by the semiconductor chips 78 arranged along the y-axis on the upper surface of the cooling device 10 using refrigerant that flows into the refrigerant circulation section 92 through the inlet 41 of the cooling device 10, diffuses throughout the refrigerant circulation section 92, and then flows out through the outlet 42. The semiconductor chips 78 are, for example, rectangular in plan view, and are arranged such that the length direction of the semiconductor chips 78 aligns with the short side direction of the fin region 95, thus overlapping a portion of the fin region 95 in plan view.

[0045] like Figure 3As shown, the top plate 20 has an upper surface (front side) 22 and a lower surface (back side) 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 also have a plating layer of nickel or the like formed on its surface. The 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 also be directly fixed to the upper surface 22 of the top plate 20 by solder or the like. 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. Thermal connections are possible between the top plate 20 and the circuit board 76, and between the circuit board 76 and the semiconductor chips 78. When the components are fixed by solder, the thermal connection is achieved using this solder.

[0046] The semiconductor device 70 may also 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 may be configured to surround the area where the circuit board 76 is disposed on the upper surface 22 of the top plate 20. The housing portion 72 may also be adhered to the upper surface 22 of the top plate 20. The housing portion 72 defines an internal space capable of housing the semiconductor chip 78, the circuit board 76, and other circuit elements. The housing portion 72 may also house the constituent elements of the semiconductor device 70, including the circuit board 76 and the semiconductor chip 78, within its internal space. A sealing portion 74 for sealing the semiconductor chip 78, the circuit board 76, and other circuit elements may be filled into the internal space of the housing portion 72. The sealing portion 74 may be, for example, an insulating member comprising a resin such as silicone or epoxy resin. Furthermore, in Figure 1 For the purpose of simplification, the illustrations of the housing section 72 and the sealing section 74 have been omitted.

[0047] The refrigerant flow section 92 is disposed on the lower surface 24 side of the top plate 20. For example... Figure 4 As shown, the refrigerant flow section 92 is approximately rectangular in cross-section with a long side 96 and a short side 93, parallel to the main surface of the top plate 20.

[0048] Refrigerant such as LLC (Long Life Coolant; antifreeze) and water flows through the refrigerant flow section 92. In the refrigerant flow section 92, the refrigerant is introduced through an inlet 41 on one side connected to the short side 93 and then discharged through an outlet 42 on the other side connected to the short side 93. The refrigerant contacts the lower surface 24 and the pin fins 94 of the top plate 20 on which the circuit board 76 is mounted, thus cooling the semiconductor device 70.

[0049] The refrigerant flow section 92 can be a sealed space that contacts the top plate 20, side wall 36, and bottom plate 64 respectively. The bottom plate 64 is configured to be directly or indirectly attached to the lower end of the side wall 36 in the negative z-axis direction, thereby sealing the refrigerant flow section 92 using the top plate 20, side wall 36, and bottom plate 64. Furthermore, indirect attachment refers to the state in which the lower end of the side wall 36 is attached to the bottom plate 64 using a sealing material, adhesive, brazing material, or a fixing agent 98 acting as a component between the lower end of the side wall 36 and the bottom plate 64. Attachment means that the refrigerant inside the refrigerant flow section 92 does not leak out from this attached portion. Preferably, the lower end of the side wall 36 and the bottom plate 64 are brazed. Furthermore, the base plate 40 and the bottom plate 64 are formed of metals with the same composition, and the brazing material can be formed of a metal with a lower melting point than the base plate 40, such as a metal containing aluminum.

[0050] The needle fins 94 are disposed in the fin region 95 within the refrigerant flow section 92, extending between the top plate 20 and the bottom plate 64. In this example, the needle fins 94 extend in the z-axis direction with their axes substantially orthogonal to the principal surfaces of both the top plate 20 and the bottom plate 64. Figure 4 As shown, in this example, the needle fin 94 is configured in a lattice shape on the xy plane and extends in the z-axis direction in a manner that is approximately orthogonal to the main surfaces of the top plate 20 and the bottom plate 64.

[0051] The needle fin 94 has a cross-section in the xy plane that is a rhombus, square, rectangle, or other quadrilateral or hexagonal polygon. For example, the needle fin 94 in this example can be substantially rhomboid in the cross-section of the xy plane. The needle fin 94 can each have an angle of 90°. The lengths of a pair of diagonals of the rhombus can be the same or different.

[0052] Multiple needle fins 94 are arranged at equal intervals, with one side of each fin parallel to the main direction MS. The main direction MS is a direction that forms an angle greater than -45° and less than 45° with respect to the straight line IO. The matrix direction of the multiple needle fins 94 is configured to form an angle with respect to the straight line IO. One side of each of the multiple needle fins 94 parallel to the matrix direction forms an angle greater than -40° and less than -20° or greater than 10° and less than 40° with respect to the straight line IO.

[0053] Figures 5-7 This is a diagram illustrating an example of the configuration of the finned area 95, inlet 41, outlet 42, and needle fins 94 in the cooling device 10. Figure 5 In the example, multiple needle fins 94 are arranged such that the mainstream direction MS forms an angle θ1 of approximately 35° with the straight line IO. Figure 6 In the example, multiple needle fins 94 are configured such that the mainstream direction MS forms an angle θ1 of approximately -35° with the straight line IO. Figure 7In the example, multiple needle wings 94 are configured such that the mainstream direction MS forms a 0° angle with the straight line IO.

[0054] Figure 8 This is a graph showing the relationship between angle θ1 (degrees) and refrigerant flow rate. θ1 (degrees) is the angle formed by the straight line IO connecting the centers of inlet 41 and outlet 42 and the mainstream refrigerant flow direction MS. The refrigerant flow rate is as follows: Figure 4 The minimum flow rate is shown directly below the six semiconductor chips 78 arranged along the y-axis. The refrigerant flow rate was determined through thermofluid simulation. The curves clearly show that when the mainstream direction MS is above -40° and below -20° or above 10° and below 40°, the minimum refrigerant flow rate is higher than when the mainstream direction MS is 0°. Furthermore, when the mainstream direction MS is above -40° and below -30° or above 30° and below 40°, the minimum refrigerant flow rate is further increased.

[0055] Furthermore, other simulations evaluating the thermal resistance at the point directly below the six semiconductor chips 78 clearly demonstrate that, in the semiconductor module 10 with a mainstream direction MS of 35°, thermal performance is improved compared to the case where the mainstream direction MS is 0°, and pressure loss is also reduced.

[0056] Figure 9 This is a diagram showing a modified example of the configuration of the fin area 95, inlet 41, outlet 42, and needle fins 94 in the cooling device 10. The plurality of rhomboid needle fins 94 may each have diagonals of different lengths and angles greater than 60° and less than 90° on the xy plane.

[0057] Figure 10 , Figure 11 This is an enlarged view of Needlewing 94. Figure 10 A rhomboid fin 94 with an angle α of 90° is shown on the xy plane. Multiple fins 94 are arranged at equal intervals such that they are spaced g apart, and their edges are parallel to the main direction MS. The fins 94 are arranged on a square grid on the xy plane. The diagonals of the fins 94 are parallel to the arrangement direction AD. Figure 11 A rhomboid needle fin 94 with an angle β greater than 60° and less than 90° on the xy plane is shown. Multiple needle fins 94 are arranged at equal intervals such that they are spaced g apart, and their respective edges are parallel to the main direction MS. The needle fins 94 are arranged on a tilted grid on the xy plane. In this case, the diagonals of the needle fins 94 are parallel to the arrangement direction AD.

[0058] The spacing g of the needle fins 94 is, for example, 0.6 mm or more and 2.0 mm or less, preferably 0.9 mm or more and 1.5 mm or less. The needle fins 94 can be manufactured by cutting, keeping the corners of the cut sides intact, or the corners of the needle fins 94 can be chamfered. When chamfering is performed, the radius (R) is, for example, 0.5 mm or less. The cross-sectional area of ​​the xy plane of the needle fins 94 is, for example, 1 mm². 2 Above and 9mm 2 Below. If the needle wing 94 is square when viewed from above, then the length of one side of the needle wing 94 is approximately 1mm to 3mm. The height of the needle wing 94 is, for example, more than 4mm and less than 6mm.

[0059] The pin fin 94 has an upper end and a lower end facing each other in the z-axis direction. The upper end is thermally and mechanically connected to 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 pin fin 94 is integrally formed with the top plate 20, the upper end of the pin 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 pin fin 94 is fixed to the base plate 64 by an adhesive 98. The lower end of the pin fin 94 can also be separated from the base plate 64. If there is a gap between the pin fin 94 and the base plate 64, even if the base plate 64 warps, it is difficult to generate stress between the pin fin 94 and the base plate 64. The heat generated by each semiconductor chip 78 moves toward the refrigerant passing near the pin fin 94. Thus, each semiconductor chip 78 is cooled.

[0060] like Figure 4 As shown by the dashed line, the fin area 95 of the refrigerant flow section 92 is a rectangle that is longer in the direction of the long side 96 than in the direction of the short side 93 when viewed from above. The needle fins 94 can also be configured such that, per unit length, the number of needle fins 94 in the direction of the long side 96 of the refrigerant flow section 92 is greater than the number of needle fins 94 in the direction of the short side 93. As an example, the ratio of the number of needle fins 94 arranged in the direction of the long side 96 of the refrigerant flow section 92 to the number of needle fins 94 arranged in the direction of the short side 93 of the refrigerant flow section 92 may be within a specified range. The fin area 95 includes a region with needle fins 94 and flow paths between the needle fins 94. Furthermore, as shown, in this example, the needle fins 94 are arranged squarely in the fin area 95, but they may also be arranged alternately rather than squarely. Additionally, the spacing between adjacent needle fins 94 may be narrower than the width of the needle fin 94 itself. Furthermore, as... Figure 4 As shown, in this example, the U-phase component 70U, the V-phase component 70V, and the W-phase component 70W are all arranged inside the fin region 95, but some of them can also be arranged outside the fin region 95.

[0061] Additionally, the refrigerant flow section 92 includes a first header 30-1 and a second header 30-2 configured to sandwich the fin area 95 when viewed from above. The header 30 refers to a space within the refrigerant flow section 92 with a height exceeding a predetermined height (length in the z-axis direction). This predetermined height may be the distance between the top plate 20 and the bottom plate 64.

[0062] The first header 30-1 is located on the side of the wing region 95 further along its shorter side 93, communicating with the inlet 41 located at position Pi, and extending in the direction of its longer side 96. The second header 30-2 is located on the other side of the wing region 95 further along its shorter side 93, communicating with the outlet 42 located at position Po, and extending in the direction of its longer side 96. The directions in which the first header 30-1 and the second header 30-2 extend may also be parallel to the direction of the longer side 96 of the wing region 95. Furthermore, the first header 30-1 is an example of a connected region, and the second header 30-2 is an example of a connected region.

[0063] It can also be done through, for example Figure 4 As shown, multiple needle fins 94 are arranged along the mainstream direction MS to form a step ST composed of multiple needle fins 94 along the outer edge of the fin region 95. The step ST can be used to adjust the refrigerant flow, thereby improving the refrigerant velocity distribution along the long side direction (y-axis direction) of the fin region 95. Multiple steps ST can be provided along the outer edge of the fin region 95, and the lengths of adjacent steps ST can be the same or different.

[0064] According to the semiconductor module 100 of this embodiment, which has the above structure, in the cooling device 10 installed on the semiconductor device 70, the main flow direction of the refrigerant flowing in the refrigerant flow section 92, which has a roughly rectangular cross-section in the xy plane, is the direction of the shorter side 93 of the roughly rectangular shape, and the fins 94 disposed in the refrigerant flow section 92 have a rhomboid cross-sectional shape in the xy plane. Therefore, according to the semiconductor module 100 of this embodiment, it is possible to uniformly cool multiple heat sources of the semiconductor device 70 that generate heat during the operation of the semiconductor module 100, while reducing the flow rate loss of the refrigerant flowing in the refrigerant flow section 92, thereby improving heat dissipation efficiency.

[0065] Furthermore, according to the semiconductor module 100 of this embodiment, the inlet 41 and outlet 42 in the cooling device 10 are located at opposite ends of the refrigerant flow section 92, which is approximately rectangular in the xy plane, along its diagonal direction. The fin region 95 of the refrigerant flow section 92 is configured such that the number of fins 94 along the long side 96 is greater than the number of fins 94 along the short side 93, and the fin region 95 is approximately rectangular, longer along the long side 96 than along the short side 93. The refrigerant flow section 92 includes a first header 30-1 and a second header 30-2 configured to sandwich the fin region 95 in a top view. The first header 30-1 is located on the side closer to the short side 93 than the fin region 95 and communicates with the inlet 41, extending along the long side 96. The second container 30-2 is located on the other side of the wing area 95, closer to the short side 93, and is connected to the outlet 42, extending in the direction of the long side 96.

[0066] According to the semiconductor module 100 of this embodiment with such a structure, the refrigerant flowing into the refrigerant circulation section 92 from the inlet 41 collides with the needle fins 94 of the fin region 95, diffuses within the first header 30-1, and gradually advances towards the outlet 42, which is located diagonally opposite to the inlet 41 in the direction of the refrigerant circulation section 92, and is discharged from the outlet 42. Therefore, compared to the case where the refrigerant inlet and outlet are located at opposite ends of the refrigerant circulation section 92 in the direction of the short side 93 (θ = 0°), the semiconductor module 100 of this embodiment can more efficiently and uniformly cool the multiple heat sources of the semiconductor device 70 that generate heat during the operation of the semiconductor module 100.

[0067] Figure 12 yes Figure 3 A magnified view of region A in the image. Wherein... Figure 12 The diagram shows how to make Figure 3 The state of region A after rotating 180 degrees. Additionally, in Figure 12 In the above, T1 represents the thickness of the fastening part 21 of the top plate 20 in the z-axis direction, T2 represents the thickness of the fin area 95 of the top plate 20 in the z-axis direction, T3 represents the thickness of the side wall 36 in the x-axis direction, and T4 represents the thickness of the bottom plate 64 in the z-axis direction.

[0068] like Figure 12As shown, in the cooling device 10 of this example, the thickness T1 of the fastening part 21 can also be 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, the 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 may be applied when the semiconductor module 100 is firmly fastened to the external device by bolts or the like can be suppressed.

[0069] Furthermore, the thickness T3 of the sidewall 36 can also be 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, 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 twisting of the fin region 95 in the top plate 20 due to mechanical or thermal effects can be suppressed.

[0070] Furthermore, the thickness T4 of the base plate 64 can be thicker than either the thickness T2 in at least the fin region 95 of the top plate 20 or the thickness T3 of the sidewall 36, and it can also 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 facilitated.

[0071] In addition, Figure 12 In the diagram, C1 represents the outline of the base plate 64 when viewed from above, and C2 represents the outline of the side wall 36. In the cooling device 10 of this example, the outline C1 of the base plate 64 may also be located inside the outline C2 of the side wall 36.

[0072] Furthermore, in this example, the step portion 65 protrudes from the main surface of the base plate 64 and, when viewed from above, has a profile that is slightly smaller than the inner perimeter of the side wall 36 and roughly consistent with the inner perimeter of the side wall 36. Thus, the step portion 65 functions in determining the position of the side wall 36 by contacting the side wall 36 with at least two different surfaces when fixing the base plate 64 to the side wall 36.

[0073] Alternatively, the corner of the side of the base plate 64 that is fixed to the side wall 36 in the top view of this example can be chamfered. In the following description, the part of the base plate 64 obtained after this chamfering is sometimes referred to as the chamfered part 66. When the base plate 64 is fixed to the side wall 36 using a solder or other adhesive 98, solder slump may occur on the outside of the fixed area. In contrast, by performing chamfering beforehand to give the base plate 64 the chamfered part 66 described above, and fixing the base plate 64 to the side wall 36 with the base plate 64 positioned above the side wall 36 in the direction of gravity as shown before the adhesive 98 solidifies, the adhesive 98 has an area where solder feet are formed, thereby preventing solder slump.

[0074] Furthermore, the chamfered portion 66 can be chamfered using either C-cut or R-cut methods. Additionally, the lower corners of the sidewall 36 and the needle fin 94 in the negative z-axis direction can also be chamfered for the same purpose.

[0075] Figure 13 This is a diagram illustrating a schematic representation of 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 a motor to generate all propulsion, or a hybrid vehicle that uses both an electric drive device such as a motor and an internal combustion engine driven by fuel such as gasoline.

[0076] The vehicle 200 includes a control device 210 (external device) for controlling electrically driven equipment such as motors. A semiconductor module 100 is provided in the control device 210. The semiconductor module 100 can control the power supplied to the electrically driven equipment.

[0077] exist Figure 4 In the illustrated embodiment, the inner surface of the sidewall 36 of the cooling device 10 can be octagonal when viewed from above. In this embodiment, in the refrigerant flow section 92 defined by the sidewall 36, a first header 30-1 and a second header 30-2 can be arranged side-by-side on one side of the short side of the fin area 95, and needle fins 94 are arranged between the first header 30-1 and the second header 30-2. Furthermore, in this embodiment, the needle fins 94 can be arranged in a grid pattern, preferably a diagonal grid or a rhomboid grid pattern. In this embodiment, the inlet 41 and outlet 42 are arranged diagonally adjacent to the fin area 95 in the refrigerant flow section 92. When viewed from above, the openings of the inlet 41 and outlet 42 can have a length in the long side 96 direction greater than their length in the short side 93 direction.

[0078] Figure 14This 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 for driving a motor in a vehicle.

[0079] In semiconductor module 100, semiconductor chips 78-1, 78-2, and 78-3 may form the upper arm, and semiconductor chips 78-4, 78-5, and 78-6 may form the lower arm. A group of semiconductor chips 78-1 and 78-4 may form a leg (U phase). Similarly, a group of semiconductor chips 78-2 and 78-5, and a group of semiconductor chips 78-3 and 78-6 may also form legs (V phase, W phase). In semiconductor chip 78-4, the emitter electrode may be electrically connected to the input terminal N1, and the collector electrode may be electrically connected to the output terminal U. In semiconductor chip 78-1, the emitter electrode may be electrically connected to the output terminal U, and the collector electrode may be electrically connected to the input terminal P1. Similarly, in semiconductor chips 78-5 and 78-6, the emitter electrodes may be electrically connected to the input terminals N2 and N3, respectively, and the collector electrodes may be electrically connected to the output terminals V and W, respectively. Furthermore, in semiconductor chips 78-2 and 78-3, the emitter electrode may be electrically connected to the output terminals V and W respectively, and the collector electrode may be electrically connected to the input terminals P2 and P3 respectively.

[0080] Each semiconductor chip 78-1 to 78-6 can be alternately switched on and off by signals input to the 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 the other input terminals N1, N2, and N3 can also be electrically connected to each other.

[0081] In semiconductor module 100, the multiple semiconductor chips 78-1 to 78-6 can each be an RC-IGBT (reverse conduction IGBT) semiconductor chip. Furthermore, semiconductor chips 78-1 to 78-6 can each include combinations of transistors such as MOSFETs and IGBTs with diodes.

[0082] In the description of the various embodiments above, for example, words such as "approximately the same", "approximately identical", "approximately fixed", "approximately symmetrical", "approximately rhomboid" are sometimes used to describe a specific state. However, these are all intended to include cases that are substantially in that specific state, and not just cases that are strictly in that specific state.

[0083] 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. It is clear to those skilled in the art that various modifications or improvements can be made to the above embodiments. As is clearly understood from the claims, such modifications or improvements can also be included within the technical scope of the present invention.

[0084] For example, in the above embodiment, a structure is described in which a top plate 20, a side wall 36, and a needle fin 94 are integrally formed on a base plate 40. However, the structure may not be as described above. Alternatively, the top plate 20, the side wall 36, and the needle fin 94 may be formed independently and then fixed together with an adhesive 98 or the like. Alternatively, the top plate 20 and the side wall 36 may be integrally formed and then the independently formed needle fin 94 may be fixed to the top plate 20. Alternatively, the top plate 20 and the needle fin 94 may be integrally formed and then the independently formed side wall 36 may be fixed to the top plate 20.

[0085] Furthermore, in the above embodiment, the structure described is such that the needle fin 94 is integrally formed with the top plate 20 and extends toward the bottom plate 64. However, this structure is not required. The needle fin 94 may also be integrally formed with the bottom plate 64 and extend toward the top plate 20. In this case, an adhesive 98 or similar agent may be used to fix the tip of the needle fin 94 to the top plate 20.

[0086] Furthermore, for example, in the above embodiment, the structure described is that the needle fin 94 extends along the normal direction of the main surface of the top plate 20 between the top plate 20 and the bottom plate 64, that is, it extends perpendicularly to the top plate 20 and the bottom plate 64. However, it is not possible for the structure to be different. The needle fin 94 may also extend obliquely between the top plate 20 and the bottom plate 64 at an angle relative to the normal direction of the main surface of the top plate 20. In addition, the cross-sectional dimension of the needle fin 94 in the xy plane may be fixed 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 the opposite direction as it moves towards the front end.

[0087] In addition, for example, in the above embodiment, the structure is described as the semiconductor device 70 being directly fixed to the upper surface 22 of the top plate 20 of the cooling device 10, but it may not be the above structure. The semiconductor device 70 may also have a substrate exposed on the lower surface of the receiving portion 72, and the circuit board 76 is fixed to the upper surface of the substrate, and the substrate is fixed to the upper surface 22 of the top plate 20, etc.

[0088] It should be noted that the execution order of actions, processes, steps, procedures, and stages in the apparatus, systems, programs, and methods shown in the claims, description, and drawings is not specifically indicated by phrases such as "before" or "before," and can be implemented in any order as long as the output of a previous process is not used in a subsequent process. While phrases such as "firstly," "next," etc., are used to describe the flow of actions in the claims, description, and drawings for ease of explanation, this does not mean that they must be performed in this order.

[0089] Explanation of reference numerals in the attached figures

[0090] 10, 11, 12, 13: Cooling device; 20, 25: Top plate; 21: Fastening part; 22: Upper surface; 24: Lower surface; 26: Support pin; 30: Header; 30-1: First header; 30-2: Second header; 36, 37, 35: Side wall; 35-1, 36-1, 37-1: Sloping surface; 37-2: Non-sloping surface; 38: Pin; 39: Groove; 40, 45: Base plate; 41: Inlet; 42: Outlet; 50: Sloping part; 51: Groove; 64, 67: Bottom plate; 65: Stepped part; 66: Chamfer Section; 68: Hole; 70: Semiconductor device; 70U: U-phase assembly; 70V: V-phase assembly; 70W: W-phase assembly; 72: Housing section; 74: Sealing section; 76: Circuit board; 78: Semiconductor chip; 80: Through hole; 92: Refrigerant flow section; 91: Short side; 93: Short side; 96: Long side; 94, 97: Needle fin; 95: Fin area; 98: Adhesive; 99: Long side; 100: Semiconductor module; 200: Vehicle; 210: Control device; 221: Pump; 222: Inlet piping; 223: Outlet piping.

Claims

1. A semiconductor module comprising a cooling device, wherein, The cooling device includes: roof; The sidewall is connected to the top plate; A base plate that faces the top plate and is connected to the side wall; Multiple polygonal needle wings, one end of which is connected to a rectangular wing area separated from the sidewall on the surface of the top plate facing the bottom plate, and arranged in a matrix-like configuration when viewed from above. The refrigerant inlet, with the center of the refrigerant flow path at the inlet positioned close to a portion of one long side of the fin region when viewed from above; and The refrigerant outlet, with the center of the refrigerant flow path at the outlet positioned close to a portion of the other long side of the fin area when viewed from above, The matrix orientation of the plurality of needle wings forms an angle relative to the straight line connecting the inlet and outlet positions. The length of the line segment that crosses the wing region is longer than the length of the shorter side of the wing region. In this configuration, each of the plurality of needle fins has one side parallel to the mainstream direction of the refrigerant forming an angle of -40° to -20° or 10° to 40° relative to the straight line.

2. The semiconductor module according to claim 1, characterized in that, The needle-wings appear diamond-shaped when viewed from above.

3. The semiconductor module according to claim 1, characterized in that, The angle of the needle fin is 90° when viewed from above.

4. The semiconductor module according to any one of claims 1 to 3, characterized in that, The cross-sectional area of ​​the needle fin is 1 mm. 2 Above and 9mm 2 the following.

5. The semiconductor module according to any one of claims 1 to 3, characterized in that, The height of the needle fin is between 4mm and 6mm.

6. The semiconductor module according to any one of claims 1 to 3, characterized in that, The spacing between the multiple needle wings is equal.

7. The semiconductor module according to any one of claims 1 to 3, characterized in that, The spacing between the plurality of said needle wings is greater than 0.6 mm and less than 2.0 mm.

8. The semiconductor module according to any one of claims 1 to 3, characterized in that, The needle fin has rounded corners with a radius of curvature of less than 0.5 mm at each corner of its cross-section.

9. The semiconductor module according to any one of claims 1 to 3, characterized in that, The straight line forms an angle of 30° or more and 60° or less with respect to the short side of the wing region.

10. The semiconductor module according to any one of claims 1 to 3, characterized in that, The top plate, the sidewalls, and the needle fins are formed as a single unit.

11. The semiconductor module according to any one of claims 1 to 3, characterized in that, The other end of the needle wing is connected to the base plate.

12. The semiconductor module according to any one of claims 1 to 3, characterized in that, The base plate has the inlet and the outlet.

13. The semiconductor module according to any one of claims 1 to 3, characterized in that, The bottom plate is thicker than either the top plate or the side wall.

14. The semiconductor module according to any one of claims 1 to 3, characterized in that, The top plate has a circuit board on which rectangular semiconductor chips are mounted. The semiconductor chip is configured such that its length direction aligns with the short side direction of the wing region, so that it overlaps with a portion of the wing region when viewed from above.

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