Cooling device, semiconductor module, vehicle, and manufacturing method

Abstract

A cooling device that suppresses the situation where foreign matter remains between cooling fins. It is used for a semiconductor module including a semiconductor chip, and includes: a shell part, the shell part includes a top plate, a bottom plate and a side wall plate, the side wall plate is arranged between the top plate and the bottom plate, and the shell part has a refrigerant circulation part, and the refrigerant circulation part is surrounded by the top plate, the bottom plate and the side wall plate; a plurality of first cooling pins, the plurality of first cooling pins are fixed to the top plate in the refrigerant circulation part of the shell part; and a plurality of second cooling pins, the plurality of second cooling pins are fixed to the top plate in the refrigerant circulation part of the shell part, and the length in the thickness direction from the top plate to the bottom plate is longer than that of the first cooling pins, and one or more first cooling pins and one or more second cooling pins are alternately arranged more than twice along the first direction in the plane parallel to the top plate.

Description

Technical Field

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

[0002] 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, refer to Patent Documents 1 to 3).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-225530

[0004] Patent Document 2: Japanese Patent Application Publication No. 2015-15274

[0005] Patent Document 3: Japanese Patent No. 6239997

[0006] If foreign matter is caught between the cooling fins, the flow of refrigerant will be hindered. Summary of the invention

[0007] In order to solve the above technical problems, in a first embodiment of the present invention, a cooling device is provided, which is used for a semiconductor module including a semiconductor chip. The cooling device may include a shell portion, the shell portion includes a top plate, a bottom plate and a side wall plate, the side wall plate is arranged between the top plate and the bottom plate, and the shell portion has a refrigerant circulation portion, and the refrigerant circulation portion is surrounded by the top plate, the bottom plate and the side wall plate. The cooling device may include a plurality of first cooling pins, and the plurality of first cooling pins are fixed to the top plate in the refrigerant circulation portion of the shell portion. The cooling device may include a plurality of second cooling pins, and the plurality of second cooling pins are fixed to the top plate in the refrigerant circulation portion of the shell portion, and the length in the thickness direction from the top plate to the bottom plate is longer than the first cooling pins. One or more first cooling pins and one or more second cooling pins are alternately arranged more than twice along the first direction in the plane parallel to the top plate.

[0008] A space portion may be provided between the end portion of the first cooling pin on the bottom plate side and the bottom plate, and the length of the space portion in the thickness direction may be greater than 1 mm.

[0009] The first cooling pin and the second cooling pin may be arranged in a predetermined cooling fin region. The space portion may be continuously provided so as to cross the cooling fin region in a predetermined linear direction.

[0010] The width of the space portion in a direction perpendicular to both the linear direction and the thickness direction may be 1 mm or more.

[0011] One or more first cooling pins and one or more second cooling pins may be alternately arranged more than twice along a second direction different from the first direction.

[0012] A plurality of first cooling pins may be arranged between the second cooling pins in at least one of the first direction and the second direction.

[0013] The first cooling pin and the second cooling pin may be arranged at a predetermined first interval in the longitudinal direction of the top plate. The distance between the cooling pin arranged closest to the end in the longitudinal direction and the side wall plate may be at least twice the first interval.

[0014] The top plate may include: a lower surface on which a plurality of first cooling pins and a plurality of second cooling pins are fixed; and an upper surface on the opposite side of the lower surface. A recess may be provided on the upper surface of the top plate in at least a portion of an area overlapping with the plurality of first cooling pins or the plurality of second cooling pins.

[0015] The top plate may have an outer peripheral portion surrounding the recessed portion, wherein a thickness of the outer peripheral portion in a thickness direction is greater than a thickness of the recessed portion in the thickness direction.

[0016] The top plate may be a continuous one-piece plate member.

[0017] The top plate may include a lower plate-shaped portion, the lower plate-shaped portion is in the shape of a plate including an upper surface and a lower surface, and a plurality of first cooling pins and a plurality of second cooling pins are fixed to the lower surface. The top plate may include an upper frame-shaped portion, the upper frame-shaped portion is fixed to the upper surface of the lower plate-shaped portion, and a through opening is provided in an area corresponding to the recess.

[0018] The top plate may have a plurality of recesses and an interphase region (or interphase portion) sandwiched between two recesses. A third cooling pin may be arranged at a position overlapping with the interphase region (or interphase portion), wherein the length of the third cooling pin in the thickness direction is smaller than the length of the first cooling pin in the thickness direction.

[0019] According to a second aspect of the present invention, there is provided a semiconductor module including the cooling device according to the first aspect and a semiconductor device, wherein the semiconductor device is arranged above a top plate.

[0020] According to a third aspect of the present invention, a vehicle is provided, the vehicle including the semiconductor module according to the second aspect.

[0021] A fourth aspect of the present invention provides a manufacturing method, which is a manufacturing method of the cooling device of the first aspect, wherein a recessed portion is provided in a top plate. In the manufacturing method, the recessed portion may be formed by forging.

[0022] In addition, the above invention summary does not list all the essential features of the present invention. In addition, the combination of the above feature groups can also become an invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic cross-sectional view showing an example of a semiconductor module 100 according to an embodiment of the present invention.

[0024] Figure 2 This is a diagram schematically showing the arrangement of the plurality of cooling pins 94 when viewed from above (xy plane).

[0025] Figure 3 It is a perspective view showing an example of a plurality of cooling pins 94 .

[0026] Figure 4 It is a diagram showing an example of arrangement of the first cooling pin 94 - 1 and the second cooling pin 94 - 2 in the xy plane.

[0027] Figure 5 This is a diagram for explaining the space portion 98 .

[0028] Figure 6 It is a perspective view showing the top plate 20 separated from the casing 40 .

[0029] Figure 7 It is a perspective view showing another example of the casing 40 .

[0030] Figure 8 It is a perspective view showing still another example of the casing portion 40 .

[0031] Fig. 9 It is a perspective view showing the casing 40 in a state where the top plate 20 is fixed.

[0032] Fig.10 It is a perspective view showing an example of the circuit substrate 76 and the semiconductor chip 78 arranged in the recessed portion 30 .

[0033] Fig.11 It is a diagram showing an example of arrangement of the recessed portion 30 and the fin region 95 .

[0034] Fig.12 A perspective view showing a structural example of a top plate 20 having a recessed portion 30 .

[0035] Fig.13 This is a diagram showing an overview of a vehicle 200 according to an embodiment of the present invention.

[0036] Fig.14 1 is a main circuit diagram of a semiconductor module 100 according to an embodiment of the present invention.

[0037] (Explanation of symbols)

[0038] 10 cooling device; 16 short side; 18 long side; 20 top plate; 22 upper surface; 23 lower plate-shaped portion; 24 lower surface; 25 upper frame-shaped portion; 26 short side; 27 upper surface; 28 long side; 29 lower surface; 30 recessed portion; 31 through-opening; 32 outer peripheral portion; 33 outer peripheral portion; 34 interphase region; 35 interphase portion; 40 shell portion; 42 opening portion; 62 peripheral portion; 63 side wall plate; 64 bottom plate; 65 upper surface surface; 66 lower surface; 70 semiconductor device; 72 housing portion; 74 sealing portion; 76 circuit substrate; 78 semiconductor chip; 81 through hole; 82 through hole; 83 through hole; 86 through hole; 92 refrigerant flow portion; 94 cooling pin; 95 fin area; 96 row; 97 row; 98 space portion; 99 refrigerant flow path; 100 semiconductor module; 102 straight line; 104 straight line; 200 vehicle; 210 control device. DETAILED DESCRIPTION

[0039] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the following embodiments are not intended to limit the invention involved in the claims. In addition, not all combinations of features described in the embodiments are essential to the solution means of the invention.

[0040] Figure 1 It is a schematic cross-sectional view of an example of a semiconductor module 100 according to an embodiment of the present invention. The semiconductor module 100 includes a semiconductor device 70 and a cooling device 10. The semiconductor device 70 of this example is arranged above the cooling device 10. In this specification, the surface of the cooling device 10 on which the semiconductor device 70 is arranged is set as the xy plane, and the surface perpendicular to the xy plane is set as the z-axis. In this specification, in the z-axis direction, the direction from the cooling device 10 toward the semiconductor device 70 is called up, and the opposite direction is called down, but the up and down directions are not limited to the direction of gravity. In addition, in this specification, the upper surface of the surface of each component is set as the upper surface, the lower surface is set as the lower surface, and the surface or wall between the upper surface and the lower surface is set as the side surface or side wall.

[0041] The semiconductor device 70 includes one or more semiconductor chips 78 such as power semiconductor chips. As an example, the semiconductor chip 78 includes an insulated gate bipolar transistor (IGBT) formed on a semiconductor substrate such as silicon.

[0042] The semiconductor device 70 has a circuit substrate 76 and a housing portion 72. The circuit substrate 76 is, for example, a substrate having a circuit pattern on an insulating substrate. A semiconductor chip 78 is fixed to the circuit substrate 76 via solder or the like. The housing portion 72 is formed of an insulating material such as resin. The housing portion 72 has an internal space for housing the semiconductor chip 78, the circuit substrate 76, and wiring. The internal space of the housing portion 72 can be filled with a sealing portion 74 that seals the semiconductor chip 78, the circuit substrate 76, and wiring. The sealing portion 74 is an insulating member such as silicone or epoxy resin. In the semiconductor device 70, a plurality of circuit substrates 76 each having a semiconductor chip 78 fixed thereto can be arranged along the y-axis direction.

[0043] The cooling device 10 of this example has a housing portion 40, which includes a top plate 20, a bottom plate 64 and a side wall plate 63. The top plate 20 can be a plate-shaped metal plate having an upper surface 22 and a lower surface 24 parallel to the xy plane. As an example, the top plate 20 is formed of a metal containing aluminum. A semiconductor device 70 is arranged on the upper surface 22 of the top plate 20. The heat generated by the semiconductor chip 78 is transferred to the top plate 20. For example, a circuit substrate 76, a metal plate, and a thermally conductive member such as solder are arranged between the top plate 20 and the semiconductor chip 78. The circuit substrate 76 can be directly fixed to the upper surface 22 of the top plate 20 by soldering or the like. At this time, the housing portion 72 is arranged to surround the area on the upper surface 22 of the top plate 20 where the circuit substrate 76 and the like are arranged. In another example, the semiconductor device 70 may include a metal plate exposed on the lower surface of the housing portion 72 , a circuit substrate 76 fixed to the upper surface of the metal plate, and the metal plate fixed to the upper surface 22 of the top plate 20 .

[0044] The bottom plate 64 is arranged to be opposite to the lower surface 24 of the top plate 20. The bottom plate 64 has an upper surface 65, which is opposite to the lower surface 24 of the top plate 20; and a lower surface 66, which is located on the opposite side of the upper surface 65. The upper surface 65 of the bottom plate 64 and the lower surface 24 of the top plate 20 can be arranged substantially in parallel with a predetermined interval. The side wall plate 63 is arranged between the top plate 20 and the bottom plate 64. The side wall plate 63 connects the outer peripheral end of the bottom plate 64 to the top plate 20. The bottom plate 64 and the side wall plate 63 can be formed as one body.

[0045] The shell portion 40 has a refrigerant circulation portion 92, which is surrounded by the top plate 20, the side wall plate 63 and the bottom plate 64. The refrigerant circulation portion 92 is arranged between the lower surface 24 of the top plate 20 and the upper surface 65 of the bottom plate 64. The refrigerant circulation portion 92 is an area where a refrigerant such as water flows. The refrigerant circulation portion 92 can be a closed space connected to the lower surface 24 of the top plate 20.

[0046] The shell portion 40 of this example has a peripheral portion 62, and the peripheral portion 62 is arranged in a manner of surrounding the refrigerant circulation portion 92 on the xy plane. The peripheral portion 62 can have a frame shape that surrounds the refrigerant circulation portion 92 on the xy plane. The peripheral portion 62 is arranged to extend from the upper end of the side wall plate 63 along the xy plane to the outside. The outside refers to the opposite side of the refrigerant circulation portion 92. The peripheral portion 62 is configured to be in close contact with the lower surface 24 of the top plate 20 directly or indirectly. Thereby, the refrigerant circulation portion 92 is closed. In addition, indirect close contact refers to a state in which the lower surface 24 of the top plate 20 and the peripheral portion 62 are in close contact with each other via a seal, an adhesive or other member provided between the lower surface 24 of the top plate 20 and the peripheral portion 62. Close contact refers to a state in which the refrigerant inside the refrigerant circulation portion 92 does not leak from the above-mentioned close contact portion.

[0047] exist Figure 1 In the example of the embodiment, the peripheral portion 62, the side wall plate 63 and the bottom plate 64 are formed as one body and fixed to the top plate 20 by brazing or the like. In other examples, the top plate 20 and the side wall plate 63 may be formed as one body. In this case, the housing portion 40 may not have the peripheral portion 62. In addition, the bottom plate 64 may also be fixed to the side wall plate 63 by brazing or the like.

[0048] A plurality of cooling pins 94 are arranged inside the refrigerant circulation portion 92. The plurality of cooling pins 94 in this example are fixed to the lower surface 24 of the top plate 20. The cooling pins 94 are thermally connected to the top plate 20. Thus, the heat generated by the semiconductor chip 78 and the like is transferred to the cooling pins 94. By passing the refrigerant near the cooling pins 94, the heat generated by the semiconductor chip 78 is transferred to the refrigerant. Thus, the semiconductor device 70 can be cooled.

[0049] The plurality of cooling pins 94 include a plurality of first cooling pins and a plurality of second cooling pins that are longer than the first cooling pins, but Figure 1 In the figure, the lengths of all cooling pins 94 are schematically shown to be the same. The length of the cooling pin 94 refers to the length in the thickness direction (in this case, the z-axis direction) from the top plate 20 toward the bottom plate 64. A relatively large space portion is generated between the lower end of the first cooling pin, which is shorter than the second cooling pin, and the bottom plate 64. By providing the space portion, foreign matter contained in the refrigerant can pass through easily. Therefore, it is possible to prevent foreign matter from being sandwiched between the cooling pins 94 and obstructing the passage of the refrigerant.

[0050] In this example, the top plate 20 and the peripheral edge portion 62 are brazed. As an example, the top plate 20 and the peripheral edge portion 62 are formed of the same material (metal in this example), and the brazing material is formed of a metal having a lower melting point than the top plate 20 or the like.

[0051] As described above, the bottom plate 64 is arranged to be opposite to the top plate 20 in the z-axis direction and has a refrigerant flow portion 92 between the bottom plate 64 and the lower surface 24 of the top plate 20. The bottom plate 64 may refer to a portion of the shell 40 that is arranged away from the top plate 20 and parallel to the top plate 20. In this example, the bottom plate 64 is provided with two or more openings 42, and the two or more openings 42 guide the refrigerant into the refrigerant flow portion 92 or guide the refrigerant out of the refrigerant flow portion 92. Figure 1 In the cross section shown, only one opening 42 is shown. In other examples, the opening 42 may also be provided in the side wall plate 63.

[0052] Through holes for inserting screws for fastening can be provided in the top plate 20. The through holes can also be used to fix the semiconductor module 100 to an external device. The through holes are provided in a region where the top plate 20 and the peripheral portion 62 overlap in the z-axis direction in a directly or indirectly close manner.

[0053] At least a portion of the cooling pin 94 is provided between the two openings 42. One opening 42 provided so as to sandwich the cooling pin 94 functions as an inlet for introducing the refrigerant into the refrigerant circulation portion 92, and the other opening 42 functions as an outlet for leading the refrigerant out of the refrigerant circulation portion 92. The user can appropriately select which opening 42 functions as the inlet or outlet.

[0054] Figure 2 1 is a diagram showing an overview of the arrangement of the plurality of cooling pins 94 when viewed from above (xy plane). Figure 2 , the bottom plate 64 and the peripheral portion 62 are shown together. The peripheral portion 62 of this example has two sets of opposite sides 26 and 28 when viewed from above. The peripheral portion 62 of this example has a short side 26 and a long side 28. In the case where the housing portion 40 does not have the peripheral portion 62, the bottom plate 64 may have the sides 26 and 28. In addition, Figure 1 The cross section of the cooling device 10 shown is Figure 2 Corresponding to the AA section.

[0055] A through hole 86 is provided at each corner of the peripheral portion 62. On the xy plane, the peripheral portion 62 has a frame shape surrounding a predetermined area. On the xy plane, a bottom plate 64 is arranged inside the peripheral portion 62. Two openings 42 are provided on the bottom plate 64. The openings 42 of this example are arranged at two diagonal positions of the bottom plate 64, but the positions of the openings 42 are not limited thereto.

[0056] A plurality of cooling pins 94 are arranged in a fin area 95 sandwiched by two openings 42. The fin area 95 may have a side parallel to the long side 28 and a side parallel to the short side 26. The fin area 95 of this example has a refrigerant flow path 99 of a specified width between the fin area 95 and the side wall plate 63 along the long side 28. The refrigerant flow path 99 of this example extends in the y-axis direction along the long side 28. The refrigerant introduced from the opening 42 flows in the y-axis direction along the refrigerant flow path 99 while passing between the plurality of cooling pins 94 and flows in a direction toward the other opening 42. With this structure, the refrigerant passes through the entire fin area 95.

[0057] The fin region 95 is provided in a region overlapping at least the semiconductor chip 78. The fin region 95 may also be provided in a region overlapping the circuit substrate 76. The fin region 95 may also be provided in a larger range than the circuit substrate 76. With this structure, the semiconductor device 70 can be cooled. The fin region 95 is preferably provided at a position that does not overlap with the opening 42.

[0058] Figure 3 1 is a perspective view showing an example of a plurality of cooling pins 94. Each cooling pin 94 is a columnar shape having a long side in the thickness direction (z-axis direction). Figure 3 In the figure, each cooling pin 94 is schematically represented by a cylinder, but the shape of the cooling pin 94 is not limited thereto. It can also be a truncated cone or a prism.

[0059] Cooling device 10 includes a plurality of first cooling pins 94 - 1 and a plurality of second cooling pins 94 - 2 . Each cooling pin 94 is fixed to lower surface 24 of top plate 20 in refrigerant flow portion 92 .

[0060] The second cooling pin 94-2 is longer in the thickness direction (z-axis direction) than the first cooling pin 94-1. That is, the distance between the second cooling pin 94-2 and the upper surface 65 of the bottom plate 64 is smaller than the distance between the first cooling pin 94-1 and the upper surface 65 of the bottom plate 64. The lower end of the second cooling pin 94-2 may also be connected to the upper surface 65 of the bottom plate 64.

[0061] The first cooling pins 94-1 may be dispersed in two dimensions in at least two directions on the lower surface 24 of the top plate 20. The number of first cooling pins 94-1 arranged per unit area of ​​the xy plane may be uniform or different in the entire fin area 95. The first cooling pins 94-1 may be arranged at equal intervals or at unequal intervals along a specified direction of the xy plane.

[0062] By providing the first cooling pin 94-1, a relatively large space can be provided between the lower end of the cooling pin 94 and the upper surface 65 of the bottom plate 64. Therefore, foreign matter can easily pass through the space, and the foreign matter can be prevented from being retained inside the fin area 95. Therefore, uneven flow of the refrigerant caused by the foreign matter can be prevented, and pressure loss when the refrigerant is circulated can be reduced.

[0063] Figure 4 : is a diagram showing an example of the arrangement of the first cooling pin 94-1 and the second cooling pin 94-2 in the xy plane. Figure 4 Only a portion of the fin area 95 is shown. Figure 4 In the figure, the first cooling pin 94-1 is represented by a white dot, and the second cooling pin 94-2 is represented by a black dot. In addition, the white dot and the black dot represent the position of the cooling pin 94 in the xy plane, and the size of the circle does not necessarily have to be consistent with the size of the cooling pin 94.

[0064] In this example, one or more first cooling pins 94-1 and one or more second cooling pins 94-2 are alternately arranged two or more times along the first direction of the xy plane parallel to the top plate 20. Figure 4 In the example, one second cooling pin 94-2 and two first cooling pins 94-1 are alternately arranged more than twice along the first direction represented by the straight line 102. The first direction of this example is a direction parallel to the y-axis (ie, a direction parallel to the long side 28).

[0065] In addition, the period of configuring the second cooling pin 94-2 along the first direction may be constant or different in the entire fin region 95. As described above, the first cooling pin 94-1 and the second cooling pin 94-2 are repeatedly configured in the fin region 95, so that the space portion for foreign matter to pass through can be repeatedly configured in the fin region 95. Therefore, it is easy to prevent foreign matter from being retained in the fin region 95.

[0066] In addition, one or more first cooling pins 94-1 and one or more second cooling pins 94-2 may be alternately arranged two or more times in a second direction different from the first direction. Thus, the first cooling pins 94-1 and the second cooling pins 94-2 can be repeatedly arranged two-dimensionally. Therefore, it is easy to prevent foreign matter from being retained in the fin area 95. Figure 4 In the example, along the second direction represented by the straight line 104, one second cooling pin 94-2 and two first cooling pins 94-1 are alternately arranged more than twice. The second direction of this example is inclined at 60 degrees relative to the first direction, but the second direction is not limited to this. In addition, Figure 4In the example of, the cooling pins 94 are respectively arranged on the grid points of the triangular grid when viewed from above, but can also be arranged on the grid points of the rectangular grid. Here, the triangular grid can include a regular triangle grid and an equilateral triangle grid, and the rectangular grid can include a square grid.

[0067] The number of first cooling pins 94-1 provided in the fin region 95 may be greater than the number of second cooling pins 94-2. In this case, foreign matter can pass through easily. In addition, the number of first cooling pins 94-1 provided in the fin region 95 may be less than the number of second cooling pins 94-2. In this case, the total surface area of ​​the cooling pins 94 can be enlarged. The number of first cooling pins 94-1 provided in the fin region 95 may be the same as the number of second cooling pins 94-2.

[0068] like Figure 4 As shown, a plurality of first cooling pins 94-1 can be arranged between the second cooling pins 94-2 in at least one of the first direction and the second direction. By continuously arranging a plurality of first cooling pins 94-1, the width of the space for foreign matter to pass through can be increased, so that foreign matter can pass through easily.

[0069] exist Figure 4 In the example, the second cooling pins 94-2 are arranged side by side along the x-axis direction. In the x-axis direction, the first cooling pin 94-1 may be arranged between the two second cooling pins 94-2, or may not be arranged. One or more columns 97 of the first cooling pins 94-1 are arranged between each column 96 of the second cooling pins 94-2 in the x-axis direction. No second cooling pin 94-2 is arranged between the two first cooling pins 94-1 in the column 97.

[0070] As described above, by continuously arranging the relatively short first cooling pins 94-1 in the x-axis direction, the space portion 98 can be continuously provided so as to cross the fin region 95 in a predetermined straight line direction. Figure 4 In the example of FIG. 1 , the straight line direction in which the space portion 98 is provided is the x-axis direction. The space portion 98 crossing the fin region 95 means that the space portion 98 is provided continuously from one end portion to the other end portion of the fin region 95 .

[0071] The space portion 98 is a space connected to the upper surface 65 of the base plate 64. The space portion 98 includes the space between the first cooling pin 94-1 and the upper surface 65 of the base plate 64. The fin area 95 is traversed by the space portion 98, so that foreign matter entering the fin area 95 is removed more easily. In this example, the space portion 98 traverses the fin area 95 along the x-axis direction, but in other examples, the space portion 98 may traverse the fin area 95 in a straight line direction different from the x-axis direction. However, the space portion 98 preferably traverses the fin area 95 in a manner that connects the refrigerant flow path 99 on one side with the refrigerant flow path 99 on the other side.

[0072] In this example, the interval of the cooling pins 94 in the first direction (straight line 102) is set to the first interval P1. In addition, the interval of the cooling pins 94 in the second direction (straight line 104) is set to the second interval P2. The interval between two cooling pins 94 refers to the shortest distance between the ends of the two cooling pins 94. The second interval P2 may be the same as or different from the first interval P1. In addition, the third interval between the two columns 96 of the second cooling pins 94-2 is set to y1. In this example, the third interval y1 is equivalent to the width of the space portion 98 in the y-axis direction.

[0073] The distance between the cooling pin 94 disposed at the end in the long-side direction (in this example, the y-axis direction) of the bottom plate 64 and the top plate 20 and the side wall plate 63 is set to y2. The distance y2 may be more than twice the first interval P1. Thus, foreign matter can easily pass between the side wall plate 63 and the fin area 95. The distance y2 may be more than three times the first interval P1, or more than four times.

[0074] Figure 5 This is a diagram for explaining the space portion 98. Figure 5 In the figure, a plurality of cooling pins 94 arranged along the y-axis are indicated by solid lines, and cooling pins 94 arranged further to the inside in the x-axis direction than these cooling pins 94 are indicated by dotted lines.

[0075] like Figure 4 As shown, the second cooling pins 94-2 are arranged in rows 96 along the x-axis direction. The first cooling pins 94-1 are arranged between the rows 96. Therefore, a space portion 98 extending along the x-axis direction is provided between the rows 96 of the second cooling pins 94-2. Figure 5 In FIG. 1 , the space portion 98 is hatched with oblique lines.

[0076] The length of the space portion 98 in the thickness direction (z-axis direction) is set to z1. The length z1 is equivalent to the distance between the upper surface 65 of the bottom plate 64 and the lower end of the first cooling pin 94-1. The length z1 is preferably greater than 1 mm. Thus, foreign matter can pass through easily. The length z1 can be greater than 2 mm or greater than 3 mm. In addition, the length z2 of the first cooling pin 94-1 can be greater than half of the distance z3 between the lower surface 24 of the top plate 20 and the upper surface 65 of the bottom plate 64 (that is, the thickness of the refrigerant circulation portion 92) or greater than three quarters. By ensuring the length of the first cooling pin 94-1, the passage of foreign matter can be facilitated and heat can be efficiently dissipated.

[0077] like Figure 5As shown, the cooling pin 94 is in the shape of a column with a substantially constant cross-sectional area in the xy plane. In addition, at least a portion of the cooling pin 94 may be in the shape of a cone with a smaller cross-sectional area as it approaches the bottom plate 64. This makes it easier for foreign matter that has entered the fin area 95 to move toward the space portion 98. The first cooling pin 94-1 may also be in the shape of a cone.

[0078] In addition, the width y1 of the space portion 98 in the y-axis direction is preferably 1 mm or more. This allows foreign matter to pass through easily. The width y1 may be 2 mm or more, or 3 mm or more.

[0079] Figure 6 1 is a perspective view showing a top plate 20 separated from the housing 40. The top plate 20 has two sets of opposite sides 16 and 18 in the xy plane. The top plate 20 in this example is a substantially rectangular shape having short sides 16 and long sides 18. In this example, the short sides 16 are parallel to the x-axis, and the long sides 18 are parallel to the y-axis.

[0080] The top plate 20 is provided with a through hole 82, which is a part of the through hole for fixing the semiconductor module 100 to an external device. In this example, the through holes 82 are provided at the four corners of the top plate 20, but the positions and number of the through holes 82 are not limited thereto. In addition, the shape of the top plate 20 is not limited to Figure 6 The top plate 20 may have a portion protruding from each side in the xy plane. The through hole 82 may also be provided in the protruding portion.

[0081] In this example, the peripheral edge portion 62 and the top plate 20 have substantially the same outer shape in the xy plane. Figure 6 In FIG. 1 , the dotted line indicates the overlapped position when the top plate 20 and the peripheral edge portion 62 are fixed by brazing or the like. Figure 6 In the figure, the cooling pin 94 disposed in the refrigerant flow portion 92 is omitted. In addition, the brazing material between the components is also omitted.

[0082] like Figure 6 As shown, the peripheral edge portion 62 is arranged to surround the refrigerant flow portion 92 and close the refrigerant flow portion 92 together with the top plate 20, the side wall plate 63 and the bottom plate 64. The refrigerant flow portion 92 is defined by the lower surface 24 of the top plate 20, the upper surface 65 of the bottom plate 64 and the side wall plate 63.

[0083] In addition, the top plate 20 and the bottom plate 64 may have the same thickness. The peripheral edge portion 62, the side wall plate 63, and the bottom plate 64 may be formed by forging a plate-shaped metal or by other methods. Forging is a method of pressing or compressing a metal plate into a predetermined shape using a die of a predetermined shape.

[0084] Figure 72 is a perspective view showing another example of the housing portion 40. The top plate 20 and the side wall plate 63 in the housing portion 40 of this example are formed as one body. The bottom plate 64 is fixed to the lower end of the side wall plate 63 by brazing or the like. In this example, the top plate 20 and the side wall plate 63 may be formed by forging or by other methods.

[0085] Figure 8 40 is a perspective view showing another example of the housing portion 40. Figure 8 2 shows the casing 40 in a state where the top plate 20 is separated.

[0086] Fig. 9 2 is a perspective view showing the housing 40 in a state where the top plate 20 is fixed. The housing 40 of this example has a different structure from the top plate 20. Figures 1 to 7 The casing portion 40 of any of the embodiments described above is the same.

[0087] The top plate 20 of this example has one or more recesses 30 on the upper surface 22. The thickness of the top plate 20 in the recesses 30 (z-axis direction) is smaller than the thickness of the top plate 20 in the region other than the recesses 30. However, the recesses 30 do not penetrate the top plate 20.

[0088] The top plate 20 is provided with an outer peripheral portion 32 surrounding the recess 30. The outer peripheral portion 32 may be provided in an annular shape along the sides 16 and 18 of the top plate 20. The thickness of the top plate 20 in the z-axis direction at the outer peripheral portion 32 is greater than the thickness of the top plate 20 in the z-axis direction at the recess 30.

[0089] The recessed portion 30 is provided with Figure 1 The circuit substrate 76 and the semiconductor chip 78 shown in the figure. In addition, the recess 30 is arranged in at least a part of the area overlapping with the first cooling pin 94-1 or the second cooling pin 94-2 (that is, the area overlapping with the fin area 95). The overlap of the recess 30 with the fin area 95 means that when the recess 30 and the fin area 95 are projected onto the same xy plane, at least a part of the area of ​​the recess 30 overlaps with the fin area 95. Preferably, the entire area of ​​the recess 30 is arranged to overlap with the fin area 95. Preferably, the first cooling pin 94-1 and the second cooling pin 94-2 are simultaneously arranged in the area overlapping with the recess 30.

[0090] By providing the recess 30, the thickness of the top plate 20 between the circuit substrate 76 and the cooling pin 94 can be reduced, and the heat generated by the semiconductor device 70 can be efficiently transferred to the cooling pin 94. In addition, by increasing the thickness of the top plate 20 at the outer peripheral portion 32 surrounding the recess 30, the mechanical strength of the top plate 20 can be maintained. Thus, deformation of the top plate 20 can be suppressed.

[0091] In the case where the top plate 20 has a plurality of recesses 30, an interphase region 34 is provided between two recesses 30. The interphase region 34 is a region between the circuit substrates 76 respectively arranged in the recesses 30. In the upper surface 22 of the top plate 20 in this example, a plurality of recesses 30 are arranged along the y-axis direction. The recess 30 can be arranged to overlap with the center of the upper surface 22 of the top plate 20 in the x-axis direction. The central position of the recess 30 in the x-axis direction can also coincide with the central position of the upper surface 22. The thickness of the top plate 20 at the interphase region 34 is greater than the thickness of the top plate 20 at the recess 30. The thickness of the top plate 20 at the interphase region 34 can also be the same as the thickness of the top plate 20 at the outer peripheral portion 32. As an example, the top plate 20 can be a continuous plate member. In this case, the recess 30 can be formed by forging.

[0092] Fig.10 30 is a perspective view showing an example of a circuit substrate 76 and a semiconductor chip 78 disposed in a recess 30. One or more circuit substrates 76 are disposed in each recess 30. In this example, one circuit substrate 76 is disposed in one recess 30. The shape of the recess 30 on the xy plane may be the same as the shape of the circuit substrate 76 on the xy plane. Fig.10 The lead frame and the like connected to the circuit substrate 76 and the semiconductor chip 78 are omitted.

[0093] At least one semiconductor chip 78 is provided on each circuit board 76. In this example, circuit boards 76 and semiconductor chips 78 for a three-phase inverter are arranged on the upper surface 22 of the top plate 20. As an example, circuit boards 76 and semiconductor chips 78 for one phase are arranged in one recess 30.

[0094] Fig.11 3 is a diagram showing an example of the arrangement of the recessed portion 30 and the fin region 95. Fig.11 In FIG. 1 , the recess 30 and the fin region 95 are projected onto the same xy plane. The recess 30 is represented by a solid line, and the cooling pin 94 is represented by a dotted circle.

[0095] As described above, the recess 30 is provided in a manner overlapping with the fin region 95. The first cooling pin 94-1 and the second cooling pin 94-2 may be simultaneously arranged at least in the region overlapping with the recess 30. Thus, it is possible to suppress the situation where foreign matter remains between the cooling pins 94 below the circuit substrate 76. In addition, the first cooling pin 94-1 and the second cooling pin 94-2 may be simultaneously arranged at least in the region overlapping with the semiconductor chip 78.

[0096] A third cooling pin 94-3 may be disposed at a position overlapping the interphase region 34, wherein the length of the third cooling pin 94-3 in the z-axis direction is smaller than the length of the first cooling pin 94-1 in the z-axis direction. Fig.11In the figure, the third cooling pin 94-3 is represented by a black dot. At the position overlapping with the interphase region 34, only the third cooling pin 94-3 may be arranged, or in addition to the third cooling pin 94-3, at least one of the first cooling pin 94-1 and the second cooling pin 94-2 may be arranged. In this example, the third cooling pin 94-3 is not arranged in the area overlapping with the recess 30. The length of the third cooling pin 94-3 in the z-axis direction may be less than half the thickness of the refrigerant circulation portion 92. By providing the third cooling pin 94-3, the passage of foreign matter can be made easier. In addition, the third cooling pin 94-3 is not arranged in the area overlapping with the recess 30, so the reduction in heat dissipation performance caused by shortening the cooling pin 94 can be suppressed. Figures 1 to 6 In the illustrated housing portion 40 , the third cooling pin 94 - 3 may be provided in a region between two circuit substrates 76 .

[0097] In addition, the third cooling pin 94-3 may also be arranged in the area between the recess 30 and the side wall plate 63 in the y-axis direction. Thus, it is possible to facilitate the passage of foreign matter in the area connected to the side wall plate 63. Fig.11 Although not shown in the figure, the third cooling pin 94-3 may be arranged in the region between the recess 30 and the side wall plate 63 in the x-axis direction. As an example, all cooling pins 94 that do not overlap with the recess 30 may be third cooling pins 94-3. The arrangement of cooling pins 94 other than the third cooling pin 94-3 is similar to Figure 4 Same configuration as described in .

[0098] Fig.12 A perspective view showing a structural example of a top plate 20 having a recess 30. The top plate 20 of this example can also be applied to Figures 1 to 11 Any of the methods described in . The top plate 20 of this example has a lower plate-like portion 23 and an upper frame-like portion 25. The lower plate-like portion 23 is in the shape of a plate including an upper surface 27 and a lower surface 29. A plurality of cooling pins 94 including a first cooling pin 94-1 and a second cooling pin 94-2 are fixed to the lower surface 29. A through hole 81 as a part of the through hole 82 is provided in the lower plate-like portion 23.

[0099] The upper frame-shaped portion 25 is fixed to the upper surface 27 of the lower plate-shaped portion 23 by brazing or the like. The upper frame-shaped portion 25 is a frame-shaped member having a through opening 31 in a region corresponding to the recess 30. The through opening 31 has the same shape as the recess 30. The upper frame-shaped portion 25 has an outer peripheral portion 33 disposed around the through opening 31. The outer peripheral portion 33 is disposed in a region corresponding to the recess 30. Figure 8 The area corresponding to the outer peripheral portion 32 described in .

[0100] In addition, when the upper frame-shaped portion 25 is provided with a plurality of through openings 31, the upper frame-shaped portion 25 has an interleaving portion 35 between two through openings 31. The interleaving portion 35 is provided at the same Figure 8 The upper frame-shaped portion 25 is provided with a through hole 83 as a part of the through hole 82. By providing the structure of the lower plate-shaped portion 23 and the upper frame-shaped portion 25, the top plate 20 having the recessed portion 30 can be formed in a simple process.

[0101] Fig.13 2 is a diagram showing an overview of a vehicle 200 according to an embodiment of the present invention. The vehicle 200 is a vehicle that generates at least a portion of its propulsion force using electricity. As an example, the vehicle 200 is an electric vehicle that generates all of its propulsion force using an electric drive mechanism such as an electric motor, or a hybrid vehicle that uses both an electric drive device such as an electric motor and an internal combustion engine driven by fuel such as gasoline.

[0102] The vehicle 200 includes a control device 210 (external device) for controlling electric drive devices such as a motor. The control device 210 is provided with a semiconductor module 100. The semiconductor module 100 can control the electric power supplied to the electric drive devices.

[0103] Fig.14 1 is a main circuit diagram of a semiconductor module 100 according to an embodiment of the present invention. The semiconductor module 100 may be a part of a vehicle-mounted unit for driving a motor of a vehicle. The semiconductor module 100 may also function as a three-phase AC inverter circuit having output terminals U, V, and W.

[0104] The semiconductor chips 78-1, 78-2 and 78-3 may constitute the lower bridge arm of the semiconductor module 100, and the plurality of semiconductor chips 78-4, 78-5 and 78-6 may constitute the upper bridge arm of the semiconductor module 100. A group of semiconductor chips 78-1 and 78-4 may constitute a bridge branch. A group of semiconductor chips 78-2 and 78-5 and a group of semiconductor chips 78-3 and 78-6 may also constitute a bridge branch. The semiconductor chips 78 are arranged in the above-mentioned recess 30 in units of bridge branches.

[0105] In the semiconductor chip 78-1, 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 the semiconductor chip 78-4, 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 the semiconductor chips 78-2 and 78-3, 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 the semiconductor chips 78-5 and 78-6, the emitter electrodes may be electrically connected to the output terminals V and W, respectively, and the collector electrodes may be electrically connected to the input terminals P2 and P3, respectively.

[0106] Each semiconductor chip 78-1 to 78-6 can be alternately switched by a signal input to a control electrode pad of the semiconductor chip 78. In this example, each semiconductor chip 78 can generate heat when switched. The input terminals P1, P2, and P3 may be connected to the positive electrode of an external power source, the input terminals N1, N2, and N3 may be connected to the negative electrode, and the output terminals U, V, and W may be connected to a load. The input terminals P1, P2, and P3 may be electrically connected to each other, or the other input terminals N1, N2, and N3 may also be electrically connected to each other.

[0107] In the semiconductor module 100, the plurality of semiconductor chips 78-1 to 78-6 may be RC-IGBT (reverse conducting IGBT) semiconductor chips. In the RC-IGBT semiconductor chip, the IGBT and the freewheeling diode (FWD: Free Wheeling Diode) may be formed as one body, and the IGBT and the FWD may be connected in reverse parallel. The plurality of semiconductor chips 78-1 to 78-6 may include a combination of transistors and diodes such as MOSFET (metal-oxide semiconductor field effect transistor) and IGBT. The chip substrate of the transistor and the diode may be a silicon substrate, a silicon carbide substrate or a gallium nitride substrate.

[0108] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be added to the above embodiments. The mode in which such changes or improvements are added is also included in the technical scope of the present invention, which can be clearly understood from the description of the claims.

Claims

1. A cooling device for a semiconductor module including a semiconductor chip, characterized in that: include: a shell portion, the shell portion including a top plate, a bottom plate and a side wall plate, the side wall plate being arranged between the top plate and the bottom plate, and the shell portion having a refrigerant flow portion, the refrigerant flow portion being surrounded by the top plate, the bottom plate and the side wall plate; a plurality of first cooling pins fixed to the top plate in the refrigerant circulation portion of the shell portion; and a plurality of second cooling pins, wherein the plurality of second cooling pins are fixed to the top plate in the refrigerant flow portion of the shell portion, and are longer in the thickness direction from the top plate to the bottom plate than the first cooling pins, The bottom plate has an upper surface in contact with the refrigerant flow portion, One or more first cooling pins and one or more second cooling pins are alternately arranged more than twice along a first direction in a plane parallel to the top plate, The distance between the first cooling pin and the upper surface of the bottom plate is greater than the distance between the second cooling pin and the upper surface of the bottom plate. The top plate has a plurality of recesses and an interlaced area sandwiched between two of the recesses, A third cooling pin is arranged at a position overlapping the interphase region, and a length of the third cooling pin in the thickness direction is smaller than a length of the first cooling pin in the thickness direction.

2. The cooling device according to claim 1, characterized in that A space portion is provided between the end portion of the first cooling pin on the bottom plate side and the bottom plate, and the length of the space portion in the thickness direction is greater than or equal to 1 mm.

3. The cooling device according to claim 2, characterized in that: The first cooling pin and the second cooling pin are arranged in a predetermined cooling fin area, The space portion is continuously provided so as to cross the cooling fin region in a predetermined linear direction.

4. The cooling device according to claim 3, characterized in that The width of the space portion in a direction perpendicular to both the linear direction and the thickness direction is 1 mm or more.

5. The cooling device according to any one of claims 1 to 4, characterized in that: One or more of the first cooling pins and one or more of the second cooling pins are alternately arranged more than twice along a second direction different from the first direction.

6. The cooling device according to claim 5, characterized in that: In at least one of the first direction and the second direction, a plurality of the first cooling pins are arranged between the second cooling pins.

7. The cooling device according to any one of claims 1 to 4 and 6, characterized in that: The first cooling pin and the second cooling pin are arranged at a predetermined first interval in the long side direction of the top plate. The distance between the cooling pin disposed closest to the end in the long side direction and the side wall plate is more than twice the first interval.

8. The cooling device according to any one of claims 1 to 4 and 6, characterized in that: The top plate has: a lower surface, on which the plurality of first cooling pins and the plurality of second cooling pins are fixed; and an upper surface, the upper surface being on the opposite side of the lower surface, wherein a recess is provided on the upper surface of the top plate in at least a portion of an area overlapping with the plurality of first cooling pins or the plurality of second cooling pins.

9. The cooling device according to claim 8, characterized in that The top plate has an outer peripheral portion that surrounds the recessed portion, and a thickness of the outer peripheral portion in the thickness direction is greater than a thickness of the recessed portion in the thickness direction.

10. The cooling device according to claim 9, characterized in that The top plate is a continuous plate member.

11. The cooling device according to claim 9, characterized in that: The top plate comprises: a lower plate-shaped portion, the lower plate-shaped portion being in a plate shape including an upper surface and a lower surface, and the plurality of first cooling pins and the plurality of second cooling pins being fixed to the lower surface; and An upper frame-shaped portion is fixed to the upper surface of the lower plate-shaped portion and is provided with a through opening in a region corresponding to the recessed portion.

12. A semiconductor module, characterized in that: include: The cooling device according to any one of claims 1 to 11; as well as A semiconductor device is disposed above the top plate.

13. A vehicle, characterized in that: A semiconductor module comprising the semiconductor module according to claim 12.

14. A manufacturing method, characterized in that: The manufacturing method is the manufacturing method of the cooling device according to claim 10, The recessed portion is formed by forging.

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