阅读说明：本技术 功率半导体模块以及车辆 (Power semiconductor module and vehicle ) 是由 郷原広道 山田教文 玉井雄大 于 2019-07-30 设计创作，主要内容包括：一种功率半导体模块，包括冷却装置以及装设于冷却装置的功率半导体装置，冷却装置具有：顶板，所述顶板具有下表面；壳体部，所述壳体部包括制冷剂流通部以及将制冷剂流通部包围的外缘部，制冷剂流通部配置于顶板的下表面侧，所述壳体部配置成在外缘部处与顶板的下表面直接或间接紧贴；以及冷却翅片，所述冷却翅片配置于制冷剂流通部，顶板和壳体部配置成顶板与外缘部重叠，且具有紧固部，所述紧固部用于将顶板以及壳体部紧固于外部装置，功率半导体装置具有电路基板和端子壳体，紧固部比顶板的外周更朝外侧突出,端子壳体具有：壳体主体，所述壳体主体配置于电路基板的周围；以及加强部，所述加强部在紧固部的上表面侧延伸。(A power semiconductor module includes a cooling device and a power semiconductor device mounted on the cooling device, the cooling device having: a top plate having a lower surface; a housing portion including a refrigerant circulating portion and an outer edge portion surrounding the refrigerant circulating portion, the refrigerant circulating portion being disposed on a lower surface side of the top plate, the housing portion being disposed in direct or indirect close contact with a lower surface of the top plate at the outer edge portion; and a cooling fin disposed in the refrigerant circulation portion, the top plate and the case portion being disposed such that the top plate overlaps the outer edge portion, and having a fastening portion for fastening the top plate and the case portion to an external device, the power semiconductor device including a circuit board and a terminal case, the fastening portion projecting outward beyond an outer periphery of the top plate, the terminal case including: a case main body disposed around the circuit board; and a reinforcing portion extending on an upper surface side of the fastening portion.)

1. A power semiconductor module comprising a cooling device and a power semiconductor device mounted on the cooling device,

the cooling device is provided with: a top plate having a lower surface; a housing portion including a refrigerant circulating portion and an outer edge portion surrounding the refrigerant circulating portion, the refrigerant circulating portion being disposed on a lower surface side of the top plate, the housing portion being disposed in direct or indirect close contact with a lower surface of the top plate at the outer edge portion; and a cooling fin disposed in the refrigerant circulating portion,

the top plate and the housing portion are arranged such that the top plate overlaps the outer edge portion, and have fastening portions for fastening the top plate and the housing portion to an external device,

the power semiconductor device has a circuit substrate and a terminal housing,

the fastening portion protrudes more to the outside than the outer periphery of the top plate,

the terminal housing has: a case main body disposed around the circuit board; and a reinforcing portion extending on an upper surface side of the fastening portion.

2. The power semiconductor module of claim 1,

the top plate has two sets of opposing sides and four corners when viewed from above,

the fastening portion is provided to protrude further to the outside than the outer periphery of the top plate at least one of the corner portions,

an opening portion that connects the refrigerant circulating portion and the outside is provided in the case portion,

the opening is disposed so as to face the corner portion of the top plate at which the fastening portion is provided.

3. The power semiconductor module of claim 1,

the height of the reinforcement part is equal to or less than the height of the housing main body.

4. The power semiconductor module of claim 1,

the reinforcing portion and the fastening portion are fixed by an adhesive.

5. The power semiconductor module of claim 1,

the reinforcement portion protrudes further outward than the outer periphery of the case main body.

6. The power semiconductor module of claim 1,

the reinforcing portion has: a planar portion disposed around a through hole penetrating vertically; and a cylindrical portion surrounding the planar portion and being thicker than the planar portion in a vertical direction.

7. The power semiconductor module of claim 1,

the reinforcement portion is connected to the case main body by a smoothly curved surface whose height gradually becomes lower from the case main body.

8. The power semiconductor module of claim 1,

the reinforcing portion is connected to the case main body by a smooth curved surface whose width gradually narrows from the case main body.

9. The power semiconductor module of claim 1,

the thickness of the housing portion at a position opposite to the center of the lower surface of the top plate is the same as that of the fastening portion.

10. The power semiconductor module of claim 1,

at the fastening portion, the top plate and the housing portion are the same thickness.

11. The power semiconductor module of claim 1,

and a reinforcing piece is arranged at the fastening part and is arranged between the top plate and the outer edge part.

12. A vehicle characterized by comprising the power semiconductor module of claim 1.

Technical Field

The invention relates to a power semiconductor module and a vehicle.

Background

Conventionally, there is known a structure in which a cooling device is provided in a semiconductor module including a semiconductor element such as a power semiconductor chip (for example, see patent documents 1 to 5).

Patent document 1: japanese patent laid-open publication No. 2017-17195

Patent document 2: japanese patent laid-open No. 2014-179563

Patent document 3: japanese patent laid-open No. Hei 7-176642

Patent document 4: WO2013/157467

Patent document 5: japanese patent laid-open publication No. 2017-183421

When the temperature of the cooling device changes due to a change in the environmental temperature, heat generation of the semiconductor device, or the like, stress acts on a fastening portion that fastens the cooling device to an external device or the like.

Disclosure of Invention

In order to solve the above-described problems, a first aspect of the present invention provides a power semiconductor module including a cooling device and a power semiconductor device mounted on the cooling device. The cooling device may further include: a top plate having a lower surface; a housing portion including a refrigerant circulating portion and an outer edge portion surrounding the refrigerant circulating portion, the refrigerant circulating portion being disposed on a lower surface side of the top plate and disposed in direct or indirect close contact with a lower surface of the top plate at the outer edge portion; and a cooling fin disposed in the refrigerant circulating portion. The top plate and the housing portion may be arranged such that the top plate overlaps the outer edge portion, and may include a fastening portion for fastening the top plate and the housing portion to an external device. The power semiconductor device may have a circuit board and a terminal housing. The fastening portion may protrude outward from the outer periphery of the top plate. The terminal housing may also have: a case main body disposed around the circuit board; and a reinforcing portion extending on an upper surface side of the fastening portion.

The top plate may also have two sets of sides and four corners that oppose each other in a top view. The fastening portion may be provided to protrude further to the outside than the outer periphery of the top plate at least one corner portion. The case may be provided with an opening portion connecting the refrigerant circulating portion and the outside. The opening may be disposed so as to face a corner portion of the top plate where the fastening portion is provided.

The height of the reinforcement portion may be equal to or lower than the height of the housing main body. The reinforcing portion and the fastening portion may be fixed together by an adhesive. The reinforcement portion may protrude further outward than the outer periphery of the case main body.

The reinforcing portion may have: a planar portion disposed around a through hole penetrating vertically; and a cylindrical portion surrounding the planar portion and being thicker than the planar portion in the vertical direction. The reinforcing portion may be connected to the housing main body by a smooth curved surface whose height gradually decreases from the housing main body. The reinforcement portion may be connected to the case main body by a smoothly curved surface whose width gradually narrows from the case main body.

It is also possible that the thickness of the case portion at a position opposite to the center of the lower surface of the top plate is the same as the thickness thereof at the fastening portion. It is also possible that the top plate and the housing part are of the same thickness at the fastening part. A reinforcement may be further provided at the fastening portion, and the reinforcement may be provided between the top plate and the outer edge portion.

In a second aspect of the present invention, a vehicle is provided that includes the power semiconductor module.

The above summary of the present invention does not list all the necessary features of the present invention. Further, a combination of the above feature groups can also be an invention.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of a power semiconductor module 100 according to an embodiment of the present invention.

Fig. 2A is a diagram showing an example of the shape of the top plate 20 in a plan view (xy plane).

Fig. 2B is a diagram illustrating a protruding direction of the fastening portion 81.

Fig. 3 is a diagram showing an example of the shape of the case 40 in a plan view (xy plane).

Fig. 4 is a diagram showing an example of the shape of the power semiconductor device 70 in a plan view (xy plane).

Fig. 5 is an exploded perspective view of the power semiconductor module 100.

Fig. 6 is a partially enlarged perspective view of an example of the reinforcement portion 171-1.

Fig. 7 is a partially enlarged perspective view of the comparative example.

Fig. 8 is a partially enlarged perspective view of another example of the reinforcing portion 181.

Fig. 9 is a schematic cross-sectional view showing an example of another power semiconductor module 102.

Fig. 10 is a view showing an example of the shape of the stiffener 30 in a plan view (xy plane).

Fig. 11 is a diagram schematically showing a vehicle 200 according to an embodiment of the present invention.

Fig. 12 is a main circuit diagram of the power semiconductor module 100 according to the embodiment of the present invention.

(symbol description)

10 a cooling device; 11 outer side surface; 13 inner side surface; 16 an upper surface; 19 corner portions; 20 a top plate; 22 an upper surface; 24 lower surface; 26 short sides; 28 long side; 29 corner portions; 30 a reinforcing member; 34 medial side; 36 outer side surface; a housing portion 40; 42 an opening part; 62 frame parts; 63 side walls; 64 a base plate; 70 power semiconductor devices; 72 a terminal housing; 74 a sealing part; 76 a circuit substrate; 78 a semiconductor chip; 79 through holes; 80 a fastening part; 81 a fastening part; 82 through holes; 83 a fastening part; 84 through holes; 85 a fastening part; 86 through holes; 88 outer circumference; 90 tubes; 92 hollow space (refrigerant circulating part); 94 cooling fins; 95 vertex; position 96; 100 power semiconductor modules; 102 a power semiconductor module; 170 a housing body; 171 a reinforcing part; 173 through holes; 175 triangular prism part; 176 a cylindrical portion; 177 plane parts; 178 a cylindrical portion; 179 corner; 180 a connecting part; 181 a reinforcing part; 185 hexagonal prism parts; 200 vehicles; 210 control the device.

Detailed Description

The present invention will be described below with reference to embodiments thereof, but the following embodiments are not intended to limit the invention according to the claims. Note that not all combinations of features described in the embodiments are essential to the means for solving the present invention.

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

The power semiconductor device 70 includes one or more semiconductor chips 78 such as power semiconductor chips. For example, the semiconductor chip 78 includes a switching element on a semiconductor substrate made of silicon, silicon carbide, or the like. The switching element is, for example, a MOSFET or an Insulated Gate Bipolar Transistor (IGBT).

The power semiconductor device 70 includes a circuit board 76 and a terminal case 72. The circuit board 76 is, for example, an insulating substrate having an upper surface and a lower surface, and is a substrate having a circuit pattern on the upper surface and a metal layer on the lower surface. The circuit pattern may also be formed of a metal layer. A semiconductor chip 78 is fixed to the circuit board 76 via solder or the like. The terminal housing 72 is formed of an insulating material such as resin. The terminal case 72 has an internal space for accommodating the semiconductor chip 78, the circuit board 76, the wiring, and the like. The internal space of the terminal case 72 is filled with a sealing portion 74, and the sealing portion 74 seals the semiconductor chip 78, the circuit board 76, the wiring, and the like. The sealing portion 74 is an insulating member such as silicone or epoxy.

The terminal housing 72 includes a housing main body 170, a plurality of reinforcing portions 171, and a side surface portion 172. The case body 170 is disposed around the circuit board 76. At least one of the plurality of reinforcing portions 171 extends outward from the connecting portion 180 with the case body 170. The plurality of reinforcing portions 171 will be described in detail later. The reinforcing portion 171, the side portion 172, and the case main body 170 are integrally molded from an insulating material such as resin such as polyphenylene sulfide (PPS). The resin for the terminal case 72 may be selected from insulating resins such as polybutylene terephthalate (PBT), polybutyl acrylate (PBA), Polyamide (PA), Acrylonitrile (ABS), Liquid Crystal Polymer (LCP), polyether ether ketone (PEEK), polybutadiene-styrene (PBS), polyurethane, and silicon, in addition to PPS. The resin may be a mixture of two or more resins. Fillers for strength and/or functionality (e.g., glass fillers) may also be included in the resin.

The cooling device 10 includes a top plate 20 and a housing 40. The top plate 20 may be a plate-shaped metal plate having an upper surface 22 and a lower surface 24 parallel to the xy-plane. For example, the top plate 20 is formed of a metal containing aluminum. A power semiconductor device 70 is mounted on the upper surface 22 of the top plate 20. On the top plate 20, heat generated by the semiconductor chip 78 is mainly transmitted through the circuit substrate 76. For example, a circuit board 76 and a heat conductive member such as solder are disposed between the top plate 20 and the semiconductor chip 78. The circuit board 76 may be directly fixed to the upper surface 22 of the top plate 20 by soldering or the like. At this time, the terminal case 72 is provided so as to surround the region where the circuit board 76 and the like are arranged in the upper surface 22 of the top plate 20. In another example, the power semiconductor device 70 may have a metal plate exposed to the lower surface of the terminal case 72, the circuit board 76 may be fixed to the upper surface of the metal plate, and the metal plate may be fixed to the upper surface 22 of the top plate 20.

The housing 40 is disposed with a cavity 92 between the housing and the lower surface 24 of the top plate 20. The cavity 92 functions as a refrigerant circulating portion through which a refrigerant such as water flows. The case 40 is disposed in direct or indirect close contact with the lower surface 24 of the top plate 20 on the upper surface 16 of the frame 62, which is the outer edge portion surrounding the cavity 92, in the xy plane. Thereby, the cavity 92 is closed. The indirect close contact means a state in which the lower surface 24 of the top plate 20 and the case 40 are in close contact with each other through a brazing material, a sealing material, an adhesive, or another member provided between the lower surface 24 of the top plate 20 and the case 40. The close contact means a state in which the refrigerant inside the cavity 92 does not leak from the above-mentioned close contact portion. Cooling fins 94 are disposed inside the cavity 92. Cooling fins 94 may also be attached to the lower surface 24 of the top plate 20. By passing the refrigerant near the cooling fins 94, the heat generated by the semiconductor chip 78 is transferred to the refrigerant. This enables the power semiconductor device 70 to be cooled. The case 40 of this example includes a frame 62, a bottom plate 64, and a side wall 63.

The frame portion 62 is arranged to surround the hollow 92 in the xy plane. The upper surface 16 of the frame 62 is disposed in direct or indirect close contact with the lower surface 24 of the top plate 20. That is, the upper surface 16 of the frame 62 and the lower surface 24 of the top plate 20 are provided to close the cavity 92. A seal or other member may be provided between the upper surface 16 of the frame 62 and the lower surface 24 of the top plate 20.

In this example, the top plate 20 and the case 40 are brazed to each other. For example, the top plate 20 and the case 40 are made of metal having the same composition, and the brazing material is made of metal having a lower melting point than the top plate 20 or the like. Metals containing aluminum can also be used as the metal. As the metal containing aluminum, an aluminum alloy such as an Al — Mn alloy (3000 series aluminum alloy) or an Al — Mg — Si alloy (6000 series aluminum alloy) may be used. As the brazing material, an aluminum alloy such as an Al — Si alloy (4000 series aluminum alloy) may be used. The aluminum alloy used in this example preferably has a proof stress at room temperature in the range of 35 to 65 MPa. The proof stress is the stress that produces a permanent deformation of 0.2% when unloaded.

The bottom plate 64 is disposed with a cavity 92 between it and the lower surface 24 of the top plate 20. The bottom plate 64 of this example is provided with two or more openings 42, and the two or more openings 42 introduce the refrigerant into the cavity 92 or lead the refrigerant out of the cavity 92. A pipe 90 for conveying the refrigerant is connected to the opening 42. The tube 90 projects toward the side opposite to the cooling fin 94 (the z-axis negative side in this example) with reference to the bottom plate 64. The pipe 90 may also be a pipe joint (nipple) for connecting an external cooling system to the cooling device 10.

The side wall 63 defines a cavity 92 by connecting the frame 62 and the bottom plate 64. The side wall 63 of this example connects the inner surface 13 of the frame 62 and the peripheral edge of the bottom plate 64. The inner surface 13 of the frame 62 faces the cavity 92. The periphery of the bottom plate 64 is the outer peripheral portion of the bottom plate 64 in the xy plane.

The top plate 20 and the housing portion 40 have fastening portions 80 fastened to each other. The fastening portion 80 and the reinforcing portion 171 fasten together the top plate 20, the case portion 40, and the power semiconductor device 70. The fastening portion 80 and the reinforcing portion 171 may be used to fix the power semiconductor module 100 to an external device.

For example, the fastening portion 80 is a region where the top plate 20 and the case portion 40 are directly or indirectly in close contact and are arranged to overlap in the z-axis direction, and is a region where a through hole 79 penetrating the top plate 20 and the case portion 40 is formed. In fig. 1, the areas of the top plate 20 and the case 40 where the through holes 79 are formed are indicated by broken lines. The fastening portion 80 of this example is provided on the frame portion 62.

Fig. 2A is a diagram showing an example of the shape of the top plate 20 in a plan view (xy plane). The top plate 20 has two sets of edges 26, 28 that face each other in plan view. The top plate 20 of this example is generally rectangular having a short side 26 and a long side 28. The top plate 20 has four corners 29. In the present description, the direction in which the short side 26 extends is referred to as the y-axis, and the direction in which the long side 28 extends is referred to as the x-axis.

The outer periphery 88 of the rectangle defined by the long side 28 and the short side 26 is the outer periphery of the top plate 20. That is, the outer periphery 88 has a shape in which the irregularities of the top panel 20 with respect to the long sides 28 and the short sides 26 are replaced with extensions of the long sides 28 and the short sides 26. In fig. 2A, the outer periphery 88 is indicated by a broken line.

The corner 29 is a region near each vertex of the outer periphery 88 of the top plate 20. As an example, as shown by a chain line in fig. 2A, four regions arranged at corners of the outer periphery 88 out of 16 regions obtained by quartering the outer periphery 88 of the top plate 20 on the x axis and the y axis are defined as the corner portions 29. In this example, the corner 29 disposed opposite the opening 42 of the case 40 is a first corner 29-1, and the other corner 29 is a second corner 29-2. The first corner portion 29-1 may include the entire region opposite to the opening portion 42, or may include only a part. In fig. 2A, a region facing the opening 42 is indicated by a broken line.

The top plate 20 is provided with one or more fastening portions 81 as a part of the fastening portion 80 shown in fig. 1. At least one fastening portion 81 may be provided in the corner portion 29. In this example, the fastening portions 81 are provided at all the corner portions 29. The fastening portion 81 may be provided on each long side 28, or the fastening portion 81 may not be provided. The fastening portion 81 may be provided in each short side 26, or the fastening portion 81 may not be provided.

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

In this example, the through-hole 82 is disposed on the outer side of the outer periphery 88 as a whole in the first fastening portion 81-1 of the first corner portion 29-1. The through hole 79 may be disposed inside the outer periphery 88 or may be disposed to overlap the outer periphery 88 at the second fastening portion 81-2 of the second corner portion 29-2 and the third fastening portion 81-3 of each side. The opening 42 is connected to a pipe 90. By disposing the through-hole 82 of the first fastening portion 81-1 outside the outer periphery 88, the work of connecting the pipe 90, the work of fastening a screw or the like to the through-hole 82 of the first fastening portion 81-1, and the like can be facilitated.

The first fastening portion 81-1 preferably protrudes outward of the outer periphery 88 by a length greater than the length of the other fastening portions 81 protruding outward of the outer periphery 88. Thus, the through-hole 82 of the first tightening portion 81-1 can be disposed away from the opening 42. Further, as described in fig. 1, the reinforcing portion 171 is provided so as to overlap with the fastening portion 81, and therefore, even if the protruding length of the first fastening portion 81-1 is increased, the strength can be maintained.

The first fastening portion 81-1 may also be provided so as to protrude from the outer periphery 88 in the xy plane in a direction parallel to the long side 28 (i.e., the x-axis direction). Here, the parallel direction may include a predetermined error. For example, the direction of projection of the long side 28 and the first fastening portion 81-8 may be inclined within 20 degrees. The fastening portion 81 may protrude in a direction connecting the apex of the fastening portion 81 (the point farthest from the outer periphery 88) and the outer periphery 88 by the shortest distance. In fig. 2A, the direction in which a part of the fastening portion 81 protrudes is indicated by an arrow. Thus, even if the protruding length of the first fastening portion 81-1 is increased, the top plate 20 is suppressed from being enlarged in the y-axis direction.

In addition, the second fastening part 81-2 may be provided to protrude in a different direction from the first fastening part 81-1. In the example of fig. 2A, the second fastening portion 81-2 protrudes in a direction at 45 degrees to the y-axis. The protruding length of the second fastening portion 81-2 is relatively small, and thus, even if protruding in the above-described direction, the top plate 20 does not become large to an equal extent. Further, the third fastening portion 81-3 protrudes from the outer periphery 88 in the y-axis direction. The length of the second fastening portion 81-2 protruding from the outer periphery 88 in the y-axis direction may be the same as the length of the third fastening portion 81-3 protruding from the outer periphery 88 in the y-axis direction. In fig. 2A, the two first fastening portions 81-1 may also be arranged symmetrically with respect to the center of the top plate 20 in the xy plane. Also, the two second fastening portions 81-2 may be arranged symmetrically with respect to the center of the top plate 20 in the xy plane.

Fig. 2B is a diagram illustrating a protruding direction of the fastening portion 81. In FIG. 2B, the vicinity of the fastening portion 81-1 and the fastening portion 81-2 is shown in an enlarged manner. In fig. 2B, the through-hole 82 of each fastening portion 81 is omitted. In this example, the point of each tightening portion 81 that is farthest from the outer periphery 88 in the xy plane is set as the apex 95. As described above, the protruding direction of the fastening portion 81 is a direction connecting the apex 95 and the outer periphery 88 by the shortest distance. However, when there are a plurality of vertices 95 as in the fastening portion 81-2, the direction connecting the average position 96 of the plurality of vertices 95 in the xy coordinate space and the outer periphery 88 by the shortest distance may be the protruding direction of the fastening portion 81. The average position 96 of the plurality of vertices 95 is a position indicating an average of coordinate values of the plurality of vertices 95 in the x-coordinate and the y-coordinate.

Fig. 3 is a diagram showing an example of the shape of the case 40 in a plan view (xy plane). The outer shape of the case 40 in the xy plane is the same as the outer shape of the top plate 20 in this example. In this example, the outer shape of the frame portion 62 corresponds to the outer shape of the case portion 40. The frame 62 has an inner surface 13 on the side of the cavity 92 and an outer surface 11 on the side opposite to the inner surface 13. Each side surface of this example is a surface substantially perpendicular to the xy-plane. In fig. 3, the outer periphery 88 of the top plate 20 is shown so as to overlap the shape of the case 40. Is there a The case 40 also has a corner 29 with an xy-plane as in the case of the top plate 20.

Similarly to the top plate 20, the case 40 is also provided at each corner 29 with a fastening portion 85 forming a part of the fastening portion 80. Further, a fastening portion 85 may be provided on any side of the case portion 40. The fastening portion 85 is provided to protrude from the frame portion 62 to the outer periphery 88. The outer side is a direction away from the center of the cavity 92 in the xy plane.

In this example, the shape of each fastening portion 85 in the xy plane is the same as the shape of the opposing fastening portion 81. Each fastening portion 85 is provided with a through hole 86. The through hole 86 is provided at a position overlapping with the through hole 82 shown in fig. 2A.

A bottom plate 64 is disposed on the xy plane inside the frame portion 62. The base plate 64 has four corners 19. The corner portion 19 may be four regions arranged at corners among 16 regions obtained by quartering the outer periphery of the bottom plate 64 on the x axis and the y axis, respectively, similarly to the corner portion 29. The fastening portion 85 is provided to protrude outward on the opposite side of the corner portion 19 of the bottom plate 64 from the opening portion 42 at the outer periphery 88 of the top plate 20.

The bottom plate 64 may be provided with an opening 42 at any one of the corners 19 to connect the cavity 92 to the outside. In the bottom plate 64 of this example, the openings 42 are provided at two corners 19 that are symmetrically arranged with respect to the center point of the bottom plate 64 on the xy plane. As shown in FIG. 2A and FIG. 3, the corner portion 29-1 of the top plate 20 provided with the fastening portion 81-1 and the corner portion 19-1 of the bottom plate 64 provided with the opening portion 42 are disposed at opposite positions.

In this example, the relative positions on the x-axis and the y-axis are used to set each corner 19 as a corner 19 on the x-axis positive side and the y-axis positive side (corner 19-1 in the example of fig. 3), a corner on the x-axis positive side and the y-axis negative side (corner 19-2 in the example of fig. 3), a corner on the x-axis negative side and the y-axis positive side (corner 19-2 in the example of fig. 3), and a corner 19 on the x-axis negative side and the y-axis negative side (corner 19-1 in the example of fig. 3). Similarly, the respective corners 29 are set as a corner 29 on the x-axis positive side and the y-axis positive side (corner 29-1 in the example of fig. 2A), a corner on the x-axis positive side and the y-axis negative side (corner 29-2 in the example of fig. 2A), a corner on the x-axis negative side and the y-axis positive side (corner 29-2 in the example of fig. 2A), and a corner 29 on the x-axis negative side and the y-axis negative side (corner 29-1 in the example of fig. 3) using relative positions on the x-axis and the y-axis. The two corners facing each other in the bottom plate 64 and the top plate 20 are the corner 19 and the corner 29 corresponding to the relative positions of the x axis and the y axis. More specifically, the corner 19 on the x-axis positive side and the y-axis positive side faces the corner 29 on the x-axis positive side and the y-axis positive side, the corner 19 on the x-axis positive side and the y-axis negative side faces the corner 29 on the x-axis positive side and the y-axis negative side, the corner 19 on the x-axis negative side and the y-axis positive side faces the corner 29 on the x-axis negative side and the y-axis positive side, and the corner 19 on the x-axis negative side and the y-axis negative side faces the corner 29 on the x-axis negative side and the y-axis negative side.

Fig. 4 is a diagram showing an example of the shape of the power semiconductor device 70 in a plan view (xy plane), and fig. 5 is an exploded perspective view of the power semiconductor module 100. In fig. 5, for simplicity of explanation, the power semiconductor device 70, the top plate 20, and the case 40 are illustrated in an exploded state, and members such as the cooling fins 94 are omitted.

The case body 170 of the power semiconductor device 70 of this example has four corners 179 corresponding to the four corners 29 of the top plate 20, and has a substantially rectangular frame shape in the xy plane. Accordingly, the outer periphery of the case main body 170 may be substantially rectangular. The corner portions 179 of the case body 170 are provided with reinforcing portions 171-1 and 171-2 extending outward from the corner portions 179, respectively. That is, the reinforcing parts 171-1 and 171-2 protrude outward from the outer periphery of the case main body 170. The outer side is a direction away from the center of the power semiconductor device 70 in the xy plane.

More specifically, the reinforcement 171-1 of the corner 179-1 opposite to the corner 29-1 protrudes outward from the outer periphery of the case main body 170 as a whole. On the other hand, a part of the reinforcing portion 171-2 of the corner portion 179-2 opposed to the corner portion 29-2 protrudes outward from the outer periphery of the case main body 170, and the other part is disposed inward from the outer periphery of the case main body 170. Two reinforcing portions 171-3 disposed inside housing body 170 are provided on each of a pair of long side portions of housing body 170, which are substantially rectangular.

The through-hole 173 penetrating the reinforcing portion 171-1 overlaps the through-hole 82 of the fastening portion 81-1 of the top plate 20 in a plan view. Similarly, the through-hole 173 penetrating the reinforcing portion 171-2 overlaps the through-hole 82 of the fastening portion 81-2 of the top plate 20 in a plan view, and the through-hole 173 penetrating the reinforcing portion 171-3 overlaps the through-hole 82 of the fastening portion 81-3 of the top plate 20 in a plan view.

The outer shape of the power semiconductor device 70 of this example on the xy plane is substantially similar to the outer shape of the top plate 20 and is slightly larger. More specifically, the outer periphery of the case main body 170 of the power semiconductor device 70 in the xy plane has a shape substantially similar to the outer periphery 88 of the top plate 20 and is slightly larger. The reinforcing portions 171 of the power semiconductor device 70 of the present example are disposed on the power semiconductor module 100 so as to face the fastening portions 81 of the top plate 20. The reinforcing portion 171 and the fastening portion 81 are overlapped with each other in a plan view, and the reinforcing portion 171 covers the entire upper surface of the fastening portion 81 so as to be in contact with the upper surface. That is, the fastening portion 81 of the top plate 20 is not exposed in a plan view. The reinforcing portion 171 and the fastening portion 81 facing each other may be fixed together by an adhesive.

Incidentally, the two reinforcing portions 171-1 of the power semiconductor device 70 extend on the upper surface sides of the two fastening portions 81-1 of the top plate 20. Similarly, the two reinforcing portions 171-2 of the power semiconductor device 70 extend on the upper surface sides of the two fastening portions 81-2 of the top plate 20, and the four reinforcing portions 171-3 of the power semiconductor device 70 extend on the upper surface sides of the four fastening portions 81-3 of the top plate 20. Further, corresponding to the case where the fastening portion 81-1 of the top plate 20 extends further outward than the fastening portion 81-2, the reinforcing portion 171-1 extends further outward with respect to the case main body 170 than the reinforcing portion 171-2.

Here, as described above, the fastening portion 80 including the fastening portion 81 of the top plate 20 and the fastening portion 85 of the case 40 is provided to protrude outward from the side wall 63 of the case 40. The fastening portions 81-1, 81-2 of the fastening portion 81 are provided so as to protrude further outward than the case main body 170 in plan view. That is, the front ends of the fastening portions 81-1 and 81-2 in the xy plane are configured as cantilever beams that are not supported by other members of the power semiconductor module 100. Therefore, the fastening portions 81-1, 81-2 are relatively easily deformed, but the strength of the fastening portion 80 can be increased by providing the reinforcing portions 171-1, 171-2.

On the other hand, the entire fastening portion 81-3 of the fastening portions 81 is located inside the case main body 170 in plan view. Thus, the reinforcing portion 171-3 opposed to the fastening portion 81-3 does not protrude further outward than the case main body 170. It can also be said that the case main body 170 itself extends on the upper surface side of the fastening portion 81-3 to reinforce the fastening portion 81-3.

As described above, by providing the reinforcement portion 171 on the upper surface of the fastening portion 80, the strength of the fastening portion 80, on which stress is easily concentrated, can be increased. Further, by providing the reinforcement portion 171, the strength of the fastening portion 80 can be increased without increasing the thickness of the side wall 63 and the bottom plate 64. Since the thicknesses of the side walls 63 and the bottom plate 64 are not increased, the side walls 63 and the bottom plate 64 are easily deformed against stress. Therefore, even if the refrigerant, the cooling fins 94, or the like inside the cavity 92 expands or contracts in accordance with a temperature change, the side walls 63 and the bottom plate 64 deform, and the volume change is easily absorbed. In addition, in the case where the power semiconductor module 100 is connected to an external device through the tube 90 and the fastening member, even if a force is applied to the case portion 40 or even if vibration is applied to the case portion 40, the force is absorbed by the side wall 63 and the bottom plate 64, and the cantilever structure of the fastening portion 80 is supported by the reinforcing portion 171. Therefore, the fastening portion 80 can be protected.

Fig. 6 is a partially enlarged perspective view of an example of the reinforcement portion 171-1. The reinforcing portion 171-1 of this example is formed by a combination of a pair of triangular prism portions 175 extending outward of the case main body 170 and one cylindrical portion 176 extending outward of these triangular prism portions 175. The pair of triangular prism portions 175 are disposed on the case body 170 side such that their apexes face each other in a plan view. The triangular prism portion 175 may be hollow and have a bottom surface. In addition, it may be solid. The triangular prism portion 175 and the cylindrical portion 176 may be disposed such that the side surfaces thereof are parallel to the z axis. Instead of the triangular prism portion 175, another columnar body such as a polygonal column or a circular column may be combined with the cylindrical portion 176.

The cylindrical portion 176 has a flat portion 177 disposed around the through hole 173, and a cylindrical portion 178 surrounding the flat portion 177. The cylindrical portion 178 is thicker than the planar portion 177 in the vertical direction. As shown in the cross-sectional view of fig. 1, the height H2, which is the vertical thickness of the cylindrical portion 178 excluding the side surface portion 172, is equal to or less than the full height H1, which is the height of the case main body 170 excluding the side surface portion 172. The cylindrical portion 176 may be hollow and may partially have a bottom surface. Further, the height of the entire housing body 170, that is, the portion of the terminal housing 72 other than the reinforcing portion 171, may be uniformly aligned to H1 to improve the strength of the housing body 170. The through hole 173 and the cylindrical portion 178 may be coaxially arranged.

The triangular prism portion 175 and the cylindrical portion 176 can increase the strength of the reinforcing portion 171 itself and also the strength of the fastening portion 80 by light and simple molding. Further, the flat surface portion 177 is formed lower than the cylindrical portion 175, and the head of a screw for fastening can be housed in the cylindrical portion 178, thereby reducing the size of the fastening portion.

(example 1)

The reinforcing portion 171-1 and the fastening portion 80-1 of the power semiconductor module 100 shown in fig. 1 to 6 are defined as example 1. In example 1, the reinforcing portion 171-1 and the fastening portion 80-1 are vertically in contact with each other, but are not fixed by an adhesive.

(example 2)

Example 2 is an example in which reinforcing portion 171-1 and fastening portion 80-1 are fixed to each other with an adhesive, with the same structure as that of reinforcing portion 171-1 and fastening portion 80-1 of power semiconductor module 100 of example 1. The adhesive is a Si-based adhesive.

Comparative example

As shown in fig. 7, the example of the power semiconductor module 100 shown in fig. 1 to 6, in which the reinforcing portion 171-1 is not provided, is a comparative example. That is, in the comparative example, the upper surface of the fastening portion 80-1 of the top plate 20 is exposed.

Specifically, in the TcP/C evaluation assuming the maximum load at the time of heat generation at all the same conditions, the stress amplitude of the maximum stress generating portion of the cooler at △ T ﹦ 100 ℃ was calculated by thermal stress simulation.