Cooler and semiconductor device

Abstract

To provide a cooler which can efficiently transfer heat to a coolant despite the fact that pressure loss in a coolant flow path is suppressed as compared with the related art, and to provide a semiconductor device including the cooler.SOLUTION: In a cooler, a heat sink 300 provided in a flow path defining region 121 facing a coolant flow path has a wire fin group 340. The wire fin group 340 includes: a first wire fin group 320 constituted of a plurality of wire fins 310 arranged adjacent to each other in a Y-axis direction; and a second wire fin group 330 including the plurality of wire fins 310 arranged adjacent to each other in the Y-axis direction. A loop-shaped part of any of the wire fins 310 constituting the first wire fin group 320 is inclined in an X-axis positive direction. The loop-shaped part of any of the wire fins 310 constituting the second wire fin group 330 is inclined in a negative X-axis direction. The first wire fin group 320 and the second wire fin group 330 are disposed adjacent to each other in the Y-axis direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a cooler and a semiconductor device. [Background technology]

[0002] As disclosed in Patent Document 1, a cooler for cooling an object to be cooled is known. This cooler includes a plate-shaped base portion to which the object to be cooled is attached, and a case portion that, together with the base portion, defines a flow path for a coolant (hereinafter referred to as a coolant flow path) for cooling the object to be cooled. The coolant is sent into the coolant flow path by a pump.

[0003] The base portion has an outer surface on which an object to be cooled is attached and an inner surface facing the coolant flow path. A group of wire fins is provided on the inner surface. The group of wire fins is composed of a plurality of wire fins aligned in the length direction of the coolant flow path at the position of the inner surface. Each wire fin extends in the width direction of the coolant flow path at the position of the inner surface.

[0004] Each wire fin has a plurality of joints and a plurality of loop-shaped portions. The plurality of joints are spaced apart in the width direction. Each joint is joined to the inner surface of the base. Each loop-shaped portion connects adjacent joints in the width direction. A coolant passes through each loop-shaped portion.

[0005] The wire fin group includes first wire fins, each of whose loop-shaped portions is inclined in a positive direction from one edge to the other edge in the width direction of the base portion, and second wire fins, each of whose loop-shaped portions is inclined in a negative direction opposite to the positive direction in the width direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2016-082237 Summary of the Invention [Problem to be solved by the invention]

[0007] In the wire fin group according to Patent Document 1, the first wire fins and the second wire fins are arranged alternately in the length direction.

[0008] In this type of arrangement, the resistance that the wire fins impose on the coolant flowing through the coolant flow path becomes too great, resulting in excessive pressure loss in the coolant flow path.When using a pump with the same output, the greater the pressure loss, the lower the flow rate of the coolant, and the lower the cooling capacity of the cooler.

[0009] An object of the present disclosure is to provide a cooler that can efficiently transfer heat to a coolant while reducing pressure loss in the coolant flow path compared to conventional coolants, and a semiconductor device equipped with such a cooler. [Means for solving the problem]

[0010] The cooler according to the present disclosure comprises: a plate-shaped base portion having an outer surface to which an object to be cooled is attached and an inner surface opposite to the outer surface; a case portion disposed opposite the inner surface of the base portion and defining, together with the base portion, a coolant flow path that is a flow path of a coolant for cooling the object to be cooled; a heat sink provided in a flow path defining region of the inner surface of the base portion facing the coolant flow path, the heat sink transferring heat of the object to be cooled to the coolant flowing through the coolant flow path; Equipped with When an imaginary Y-axis that is parallel to the length direction of the coolant flow path at the position of the inner surface and an imaginary X-axis that is parallel to the inner surface and intersects with the imaginary Y-axis are defined, The heat sink is a wire fin group in which a plurality of wire fins each extending in an X-axis direction that is a direction of the imaginary X-axis are arranged side by side in a Y-axis direction that is a direction of the imaginary Y-axis; and Each of the wire fins comprises: a plurality of junctions arranged at intervals in the X-axis direction, each junction being joined to the flow path defining region of the inner surface; a plurality of loop-shaped portions each connecting the joint portions adjacent to each other in the X-axis direction, the plurality of loop-shaped portions through which the cooling liquid passes; and The wire fin group includes: a first wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the first wire fin group is inclined in a positive direction of the X-axis, which is a direction from one end edge of the flow path defining region to the other end edge in the X-axis direction; a second wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the second wire fin group is inclined in a negative direction of the X-axis, which is a direction from the other end edge toward the one end edge of the flow path defining region; Contains, The first group of wire fins and the second group of wire fins are disposed adjacent to each other in the Y-axis direction. [Effects of the Invention]

[0011] According to the above configuration, in the first wire fin group, wire fins whose loop-shaped portions are inclined in the positive direction of the X-axis are lined up adjacent to each other in the Y-axis direction. Also, in the second wire fin group, wire fins whose loop-shaped portions are inclined in the negative direction of the X-axis are lined up adjacent to each other in the Y-axis direction. In this way, wire fins whose loop-shaped portions are inclined in the same direction in the X-axis direction are lined up adjacent to each other in the Y-axis direction.

[0012] This reduces pressure loss in the coolant flow path compared to the conventional arrangement in which wire fins with loop-shaped portions inclined toward the positive X-axis and wire fins with loop-shaped portions inclined toward the negative X-axis are arranged alternately in the Y-axis direction.

[0013] The first wire fin group and the second wire fin group are arranged adjacent to each other in the Y-axis direction, and therefore the flow of the coolant between the adjacent first wire fin group and second wire fin group is turbulent, allowing heat to be efficiently transferred from the wire fin groups to the coolant. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a semiconductor device according to a first embodiment; [Figure 2] FIG. 1 is an exploded perspective view of a semiconductor device according to a first embodiment; [Figure 3] 1 is a cross-sectional view showing a cross section perpendicular to a virtual X-axis of a semiconductor device according to a first embodiment; [Figure 4] 1 is a cross-sectional view showing a cross section perpendicular to an imaginary Y-axis of a semiconductor device according to a first embodiment; [Figure 5] FIG. 1 is a perspective view showing a wire fin group according to a first embodiment; [Figure 6] FIG. 1 is a partial cross-sectional view showing a first wire fin according to the first embodiment; [Figure 7] FIG. 10 is a partial cross-sectional view showing a second wire fin according to the first embodiment. [Figure 8] FIG. 1 is a conceptual diagram showing the distribution of bonded portions in a wire fin group according to the first embodiment. [Figure 9] FIG. 1 is a partial cross-sectional view showing a first wire fin group according to the first embodiment; [Figure 10] FIG. 1 is a partial cross-sectional view showing a second wire fin group according to the first embodiment; [Figure 11] 10 is a cross-sectional view showing a cross section perpendicular to the imaginary Y-axis of a semiconductor device according to a second embodiment; [Figure 12] FIG. 10 is a partial cross-sectional view showing a second wire fin group according to the second embodiment. [Figure 13] FIG. 10 is a perspective view showing a wire fin group according to a third embodiment. [Figure 14] 10 is a cross-sectional view showing a cross section perpendicular to the imaginary X-axis of the semiconductor device according to the fourth embodiment; [Figure 15]10 is a cross-sectional view showing a cross section perpendicular to the imaginary X-axis of the semiconductor device according to the fifth embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a semiconductor device according to an embodiment will be described with reference to the drawings, in which the same or corresponding parts are denoted by the same reference numerals.

[0016] [Embodiment 1] 1, a semiconductor device 700 according to this embodiment includes a semiconductor module 600 and a cooler 500 that cools the semiconductor module 600. The semiconductor module 600 is an example of an object to be cooled by the cooler 500.

[0017] Specifically, the semiconductor module 600 includes a power semiconductor that controls power through switching operation, and generates heat during operation. The cooler 500 cools the semiconductor module 600, with the aim of stabilizing the operation of the semiconductor module 600.

[0018] As shown in FIG. 2, the cooler 500 has a plate-shaped base portion 100 and a case portion 200 that is combined with the base portion 100.

[0019] The plate-shaped base portion 100 has an outer surface 110 and an inner surface 120 opposite to the outer surface 110 in the thickness direction of the base portion 100. A semiconductor module 600 is attached to the outer surface 110. In this embodiment, two semiconductor modules 600 are attached to the outer surface 110.

[0020] The case part 200 is disposed opposite the inner surface 120 of the base part 100. The case part 200, together with the base part, defines a coolant flow path 400, which is a flow path for a coolant for cooling the semiconductor module 600. In other words, the case part 200 is joined to the base part 100 in a liquid-tight manner.

[0021] The case 200 also defines a coolant inlet 410 through which the coolant is introduced into the coolant flow path 400, and a coolant outlet 420 through which the coolant is discharged from the coolant flow path 400. The coolant flow path 400 is connected to the coolant inlet 410 and the coolant outlet 420.

[0022] The case 200 also has a coolant inlet pipe 210 connected to the coolant inlet 410 and a coolant outlet pipe 220 connected to the coolant outlet 420 .

[0023] The cooler 500 also includes a heat sink 300 provided on the inner surface 120 of the base portion 100. The heat sink 300 is provided on the inner surface 120 of the base portion 100 in a flow path defining region 121 facing the coolant flow path 400.

[0024] The base 100 serves to transfer heat from the semiconductor module 600 to the heat sink 300. For this reason, the base 100 is made of metal, which is a material with excellent thermal conductivity. Examples of materials for the base 100 include copper and aluminum. The heat sink 300 transfers the heat from the semiconductor module 600 to the coolant flowing through the coolant flow path 400.

[0025] 3 and 4, the heat sink 300 is disposed in a gap 400a defined between the inner surface 120 of the base portion 100 and the case portion 200. The gap 400a forms part of the coolant flow path 400. The heat sink 300 rises from the inner surface 120 of the base portion 100 toward the case portion 200. The heat sink 300 may or may not be in contact with the case portion 200.

[0026] 1 to 4, the operation of the semiconductor device 700 will be described below. A pump (not shown) sends coolant through the coolant inlet pipe 210 and the coolant inlet port 410 into the coolant flow path 400. The sent coolant removes heat from the heat sink 300 in the gap 400a, flows toward the coolant outlet port 420, and is discharged into the coolant outlet pipe 220 via the coolant outlet port 420.

[0027] In this way, the heat of the semiconductor module 600 is transferred to the coolant via the heat sink 300, thereby cooling the semiconductor module 600. Note that part of the heat generated in the semiconductor module 600 can be transferred directly from part of the inner surface 120 to the coolant without passing through the heat sink 300.

[0028] To facilitate the following explanation, a right-handed XYZ Cartesian coordinate system is defined, having an imaginary Z axis parallel to the thickness direction of the plate-shaped base member 100 and an imaginary Y axis parallel to the length direction of the coolant flow path 400 in the gap 400a. With respect to the direction of the imaginary Z axis (hereinafter referred to as the Z axis direction), the direction from the case member 200 toward the base member 100 is defined as the positive Z axis direction.

[0029] When viewed in the Z-axis direction, the base portion 100 has a rectangular shape with one side extending in the direction of the imaginary Y-axis (hereinafter referred to as the Y-axis direction). The direction of the imaginary X-axis (hereinafter referred to as the X-axis direction) coincides with the direction of the other side of the base portion 100 when viewed in the Z-axis direction. Note that with respect to the Y-axis direction, the direction from the coolant inlet 410 toward the coolant outlet 420 is the positive Y-axis direction. Note that the positive Y-axis direction coincides with the flow direction of the coolant in the gap 400a when viewed from a global perspective.

[0030] The configuration of the heat sink 300 will be specifically described below.

[0031] 5, the heat sink 300 is configured by a wire fin group 340, which is a collection of multiple wire fins 310. Each of the multiple wire fins 310 that make up the wire fin group 340 extends continuously in the X-axis direction. The multiple wire fins 310 are lined up in the Y-axis direction.

[0032] Each wire fin 310 serves to transfer heat from the semiconductor module 600 to the coolant flowing through the coolant flow path 400. For this reason, each wire fin 310 is made of metal, which is a material with excellent thermal conductivity. Examples of materials for each wire fin 310 include gold, silver, copper, and aluminum.

[0033] The flow path defining region 121 covered by the wire fin group 340 has a rectangular shape with one side parallel to the imaginary Y axis and the other side parallel to the imaginary X axis when viewed in the Z axis direction. Specifically, the dimension B of the flow path defining region 121 in the X axis direction is smaller than the dimension A of the coolant flow path 121 in the Y axis direction. In other words, when viewed in the Z axis direction, the flow path defining region 121 has a rectangular shape with the Y axis direction as the longitudinal direction.

[0034] 6 shows an example of one wire fin 310. As shown in FIG. 6, each wire fin 310 has a plurality of joint portions 311 and a plurality of loop-shaped portions 312.

[0035] The multiple joints 311 are aligned at intervals in the X-axis direction. Each joint 311 is joined to a flow path defining region 121 of the inner surface 120. Each loop-shaped portion 312 connects adjacent joints 311 in the X-axis direction.

[0036] The cooling liquid flowing through the gap 400a passes through each of the loop portions 312. As the cooling liquid passes through the loop portions 312, heat from the semiconductor module 600 is transferred from the loop portions 312 to the cooling liquid.

[0037] Each wire fin 310 is formed by plastically deforming a single metal wire into a shape having a plurality of loop portions 312 and portions that become a plurality of joints 311, and then bonding each of the portions that become the joints 311 to the flow path defining regions 121 of the inner surface 120. The bonding may be achieved by brazing, ultrasonic bonding, or the like.

[0038] 5, each wire fin 310 has a width parallel to the Y-axis direction and a thickness perpendicular to the width. A cross section of each wire fin 310 parallel to the width and thickness directions has a shape that is elongated in the width direction, specifically a rectangular shape. The aspect ratio of each wire fin 310, defined as width / thickness, is 5 or greater, specifically 10 or greater.

[0039] This reduces the resistance to the coolant that collides with the wire fins 310, and thus the pressure loss, while ensuring a larger surface area of ​​each loop portion 312 exposed to the coolant than when using linear wire fins with a cross section having equal width and thickness. In other words, heat can be efficiently dissipated from each loop portion 312 to the coolant.

[0040] Continuing the description, returning to Figure 6, each loop-shaped portion 312 specifically has a pair of opposing rising portions 312a and an apex portion 312b connecting the pair of rising portions 312a.

[0041] One of the pair of rising portions 312a rises from one of the joints 311 adjacent in the X-axis direction toward the case part 200. The other of the pair of rising portions 312a rises from the other of the joints 311 adjacent in the X-axis direction toward the case part 200.

[0042] The apex 312b connects the ends of the pair of rising portions 312a that are closer to the case portion 200. The apex 312b may or may not be in contact with the case portion 200.

[0043] Furthermore, each of the loop-shaped portions 312 rising from adjacent joints 311 in the X-axis direction toward the case portion 200 has a rising portion 312a that is inclined in the X-axis direction as it approaches the case portion 200.

[0044] 5, the definition of the direction in the X-axis direction will be described to explain the inclination of the loop-shaped portion 312. According to the XYZ Cartesian coordinate system defined above, the direction from one edge 121a in the X-axis direction of the flow path defining region 121 (hereinafter referred to as one edge in the X-axis direction) toward the other edge 121b (hereinafter referred to as the other edge in the X-axis direction) is the positive X-axis direction. The direction opposite to the positive X-axis direction, i.e., the direction from the other edge 121b in the X-axis direction of the flow path defining region 121 toward the one edge 121a in the X-axis direction, is the negative X-axis direction.

[0045] 6, each of the loop-shaped portions 312 is inclined in the positive direction of the X-axis as it approaches the case portion 200. Hereinafter, the wire fin 310 in which each of the loop-shaped portions 312 is inclined in the positive direction of the X-axis in this manner will be referred to as a "first wire fin 310A."

[0046] 7 shows another wire fin 310. In this wire fin 310, each loop-shaped portion 312 is inclined in the negative X-axis direction as it approaches the case portion 200. Hereinafter, this wire fin 310 in which each loop-shaped portion 312 is inclined in the negative X-axis direction will be referred to as a "second wire fin 310B."

[0047] As described above, the reason for tilting the loop-shaped portion 312 of the wire fin 310 in the positive or negative X-axis direction is to maximize the surface area of ​​the loop-shaped portion 312 that is exposed to the coolant. In other words, tilting the loop-shaped portion 312 allows the loop-shaped portion 312 to have a longer length along the loop than a configuration in which the loop-shaped portion 312 stands straight up in the Z-axis direction.

[0048] Returning to Fig. 5, the configuration of wire fin group 340 will be described. Wire fin group 340 includes first wire fin group 320 and second wire fin group 330. First wire fin group 320 is a group of first wire fins 310A described above. Second wire fin group 330 is a group of second wire fins 310B described above.

[0049] The first wire fin group 320 is made up of a plurality of first wire fins 310A arranged adjacent to each other in the Y-axis direction.

[0050] In this specification, "multiple first wire fins 310A lined up adjacent to each other in the Y-axis direction" means that, regardless of which first wire fin 310A that constitutes the first wire fin group 320 is focused on, there is another first wire fin 310A that is adjacent to that first wire fin 310A in the Y-axis direction within that first wire fin group 320.

[0051] In this embodiment, three first wire fins 310A constitute the first wire fin group 320. However, the number of first wire fins 310A constituting the first wire fin group 320 is not particularly limited as long as it is two or more.

[0052] On the other hand, the second wire fin group 330 is made up of a plurality of second wire fins 310B arranged adjacent to each other in the Y-axis direction.

[0053] In this specification, "multiple second wire fins 310B arranged adjacent to each other in the Y-axis direction" means that regardless of which second wire fin 310B that constitutes the second wire fin group 330 is focused on, there is another second wire fin 310B in the second wire fin group 330 that is adjacent to that second wire fin 310B in the Y-axis direction.

[0054] In this embodiment, three second wire fins 310B constitute the second wire fin group 330. However, the number of second wire fins 310B constituting the second wire fin group 330 is not particularly limited as long as it is two or more.

[0055] The wire fin group 340 has an arrangement structure in which the first wire fin group 320 and the second wire fin group 330 are adjacent to each other in the Y-axis direction.

[0056] Specifically, the first wire fin groups 320 and the second wire fin groups 330 are alternately arranged in the Y-axis direction to form a wire fin group 340 that covers the flow path defining region 121. That is, the wire fin group 340 is formed of multiple pairs of first wire fin groups 320 and second wire fin groups 330 that are adjacent to each other in the Y-axis direction.

[0057] As described above, according to this embodiment, in the first wire fin group 320, first wire fins 310A whose loop-shaped portions 312 are inclined in the positive direction of the X axis are lined up adjacent to each other in the Y axis direction. Also, in the second wire fin group 330, second wire fins 310B whose loop-shaped portions 312 are inclined in the negative direction of the X axis are lined up adjacent to each other in the Y axis direction. In this way, wire fins 310 whose loop-shaped portions 312 are inclined in the same direction in the X axis direction are lined up adjacent to each other in the Y axis direction.

[0058] Therefore, compared to a configuration in which the first wire fins 310A and the second wire fins 310B are arranged alternately in the Y-axis direction, the resistance that the coolant flowing through the gaps 400a receives from the wire fin group 340, and therefore the pressure loss in the coolant flow path 400, is reduced. Therefore, compared to a configuration in which the first wire fins 310A and the second wire fins 310B are arranged alternately in the Y-axis direction, the load on the pump is reduced, and the flow rate of the coolant flowing through the coolant flow path 400 can be increased. As a result, the cooling capacity of the cooler 500 can be improved.

[0059] 5, the first wire fin group 320 and the second wire fin group 330 are arranged adjacent to each other in the Y-axis direction. Therefore, in each pair of adjacent first wire fin group 320 and second wire fin group 330, the flow of the coolant is turbulent between the first wire fin group 320 and the second wire fin group 330. As a result, heat can be efficiently transferred from the wire fin group 340 to the coolant.

[0060] 5, the dimension A of the flow path defining region 121 in the Y-axis direction is greater than the dimension B of the flow path defining region 121 in the X-axis direction (A>B). In other words, the length of the gap 400a in the Y-axis direction shown in FIG. 6 is greater than the width of the gap 400a in the X-axis direction.

[0061] Therefore, compared to a configuration in which the dimension A in the Y-axis direction of the flow path defining region 121 is equal to or smaller than the dimension B in the X-axis direction of the flow path defining region 121 (A≦B), the flow rate of the coolant per cross-sectional area of ​​the flow path can be increased. This contributes to improving the cooling capacity of the cooler 500.

[0062] Here, the term "cross-sectional area of ​​the flow path" refers to the area of ​​a cross section (hereinafter referred to as the "cross-section of the flow path") perpendicular to the imaginary Y-axis of the gap 400a shown in Fig. 6. Furthermore, in this specification, the term "flow rate" refers to the volume of the coolant passing through the cross-section of the flow path per unit time.

[0063] Hereinafter, other advantages obtained from the configuration in which the first wire fin group 320 and the second wire fin group 330 are aligned in the Y-axis direction will be described.

[0064] 6, since the loop-shaped portion 312 of the first wire fin 310A is inclined in the positive direction of the X-axis, a space (hereinafter referred to as a first space) that is free from obstacles for the coolant can be formed between the first wire fin 310A and one end edge 121a in the X-axis direction of the flow path defining region 121. Note that although one first wire fin 310A is shown in FIG. 6, the first space can be formed over the length of the first wire fin group 320 in the Y-axis direction.

[0065] 7, for the same reason, a space (hereinafter referred to as a second space) free from obstacles for the coolant can be formed between the second wire fin 310B and the other end edge 121b in the X-axis direction of the flow path defining region 121. The second space can be formed over the length of the second wire fin group 330 in the Y-axis direction.

[0066] In the first and second spaces described above, heat is not dissipated from the wire fins 310 to the coolant. However, the first wire fin group 320 and the second wire fin group 330 are aligned in the Y-axis direction. Therefore, the coolant flowing through the first space to the side of the first wire fin group 320 collides with the second wire fins 310B that constitute the second wire fin group 330 adjacent to the first wire fin group 320 in the Y-axis direction, and exchanges heat with the second wire fins 310B.

[0067] In addition, the coolant flowing through the second space to the side of the second wire fin group 330 collides with the first wire fin 310A that constitutes the first wire fin group 320 adjacent to the second wire fin group 330 in the Y-axis direction, and exchanges heat with the first wire fin 310A.

[0068] As described above, since the first wire fin group 320 and the second wire fin group 330 are aligned in the Y-axis direction, both the coolant flowing through the first space and the coolant flowing through the second space can be properly used for heat exchange with the wire fins 310.

[0069] Furthermore, the communication of the first space in the Y-axis direction is interrupted by the second wire fin group 330, and the communication of the second space in the Y-axis direction is interrupted by the first wire fin group 320, thereby suppressing unevenness in the flow of the coolant in the gap 400a. This point will be described below.

[0070] If only the first wire fin groups 320 were arranged in the Y-axis direction, the first spaces free of obstacles for the coolant would be connected in the Y-axis direction across the entire Y-axis dimension of the flow path defining region 121. Because the coolant flows through a path with minimal pressure loss, in this case, a large amount of coolant would flow into the first spaces connected in the Y-axis direction. As a result, it would be difficult to sufficiently cool the first wire fin groups 320.

[0071] Similarly, when only the second wire fin groups 330 are arranged in multiple rows in the Y-axis direction, a large amount of coolant flows into the second space that is connected in the Y-axis direction, making it difficult for the second wire fin groups 330 to be sufficiently cooled.

[0072] In contrast, according to the configuration of this embodiment, the first wire fin group 320 and the second wire fin group 330 are aligned in the Y-axis direction, so that the communication of the first space in the Y-axis direction is interrupted by the second wire fin group 330, and the communication of the second space in the Y-axis direction is interrupted by the first wire fin group 320.

[0073] As a result, there are no areas where the flow resistance of the coolant is extremely small, so the flow rate of the coolant can be prevented from being uneven in the XZ plane. Therefore, heat can be efficiently transferred from the wire fin group 340 to the coolant. This contributes to improving the cooling capacity of the cooler 500.

[0074] [Specific example of the first embodiment] A preferred embodiment of the above-mentioned first embodiment will be described below.

[0075] Fig. 8 shows the distribution of the joints 311 in the wire fin group 340. In Fig. 8, only the joints 311 of the first wire fin 310A and the second wire fin 310B are extracted and illustrated in order to clearly show the distribution of the joints 311. In addition, Fig. 8 shows an enlarged view of only a portion of the flow path defining region 121 of the inner surface 120.

[0076] As shown in FIG. 8, in each of the first wire fin group 320 and the second wire fin group 330, the bonding portions 311 are preferably distributed in a staggered pattern in the flow path defining region 121 of the inner surface 120.

[0077] In other words, it is preferable that each of the first wire fin group 320 and the second wire fin group 330 has a configuration in which the arrangement of the multiple joints 311 that make up one wire fin 310 is shifted in the X-axis direction relative to the arrangement of the multiple joints 311 that make up another wire fin 310 adjacent to that wire fin 310 in the Y-axis direction (hereinafter referred to as a staggered arrangement configuration).

[0078] However, the staggered arrangement is not essential in the first embodiment. The plurality of joints 311 may be distributed in a matrix in each of the first wire fin group 320 and the second wire fin group 330. In other words, a configuration may be adopted in which rows of the plurality of joints 311 arranged adjacently in the Y-axis direction are arranged in the X-axis direction, which is the column direction (hereinafter referred to as a matrix arrangement configuration).

[0079] However, the staggered arrangement configuration improves the efficiency of heat dissipation from the wire fin group 340 to the coolant compared to the matrix arrangement configuration. One reason for this is that the staggered arrangement configuration suppresses the development of a thermal boundary layer in the direction of the coolant flow compared to the matrix arrangement configuration. The suppression of the development of a thermal boundary layer improves the cooling capacity of the cooler 500.

[0080] Below, a particularly preferred embodiment for realizing the staggered arrangement configuration will be described.

[0081] 6 again, a particularly preferred example of the first wire fin 310A will be described. In this example, in each first wire fin 310A, the joints 311 are arranged periodically in the X-axis direction. The period, i.e., the arrangement pitch P representing the distance in the X-axis direction between adjacent joints 311 in the X-axis direction, is the same in all of the first wire fins 310A that make up the first wire fin group 320.

[0082] 7 again, a particularly preferred example of the second wire fin 310B will be described. In this example, the joints 311 are also arranged periodically in the X-axis direction in each second wire fin 310B. The period, i.e., the arrangement pitch P representing the distance in the X-axis direction between adjacent joints 311 in the X-axis direction, is the same in all second wire fins 310B that make up the second wire fin group 330.

[0083] Furthermore, the arrangement pitch P of second wire fins 310B constituting second wire fin group 330 is equal to the arrangement pitch P of first wire fins 310A constituting first wire fin group 320.

[0084] 8 again, a particularly preferred example of a staggered arrangement will be described. In this example, in each of the first wire fin group 320 and the second wire fin group 330, the arrangement of the multiple joints 311 constituting one wire fin 310 is shifted in the X-axis direction by a predetermined shift amount D with respect to the arrangement of the multiple joints 311 constituting another wire fin 310 adjacent to that wire fin 310 in the Y-axis direction.

[0085] Furthermore, in the wire fin group 340 according to this example, the arrangement of the multiple joints 311 constituting the first wire fin 310A is shifted in the X-axis direction by the above-mentioned shift amount D relative to the arrangement of the multiple joints 311 constituting the second wire fin 310B adjacent to the first wire fin 310A in the Y-axis direction.

[0086] In addition, in the wire fin group 340 according to this example, the shift amount D is common to a pair of wire fins 310 adjacent to each other in the Y-axis direction and another pair of wire fins 310 adjacent to each other in the Y-axis direction.

[0087] In the wire fin group 340 according to this example, the shift amount D is set equal to half the distance of the arrangement pitch P described above (D=P / 2).

[0088] 9 shows the first wire fin group 320 when the shift amount D is set to half the distance of the arrangement pitch P. When viewed in the Y-axis direction, the apex 312b of another first wire fin 310A adjacent to the first wire fin 310A in the Y-axis direction is disposed between a pair of apexes 312b of the first wire fin 310A adjacent to the first wire fin 310A in the X-axis direction.

[0089] Furthermore, when viewed in the Y-axis direction, the rising portion 312a of the first wire fin 310A overlaps with the rising portion 312a of another first wire fin 310A adjacent to the first wire fin 310A in the Y-axis direction.

[0090] 10 shows the second wire fin group 330 when the shift amount D is set to half the distance of the arrangement pitch P. When viewed in the Y-axis direction, the apex 312b of another second wire fin 310B adjacent to that second wire fin 310B in the Y-axis direction is disposed between a pair of apexes 312b of the second wire fin 310B adjacent to that second wire fin 310B in the X-axis direction.

[0091] Furthermore, when viewed in the Y-axis direction, the rising portion 312a of the second wire fin 310B overlaps with the rising portion 312a of another second wire fin 310B adjacent to the second wire fin 310B in the Y-axis direction.

[0092] As described above, when the shift amount D is set to half the distance of the arrangement pitch P, the rising portion 312a of one wire fin 310 overlaps with the rising portion 312a of another wire fin 310 adjacent to that wire fin 310 in the Y-axis direction. This overlapping arrangement contributes to suppressing pressure loss in the coolant flow path 400.

[0093] According to this example, the staggered arrangement configuration is adopted, which improves the efficiency of heat dissipation from the wire fin group 340 to the coolant compared to the case where a matrix arrangement configuration is adopted. Nevertheless, by setting the shift amount D to half the distance of the arrangement pitch P, the pressure loss in the coolant flow path 400 is further reduced.

[0094] [Embodiment 2] In FIGS. 9 and 10, a configuration in which the shift amount D is set to a distance that is half of the array pitch P is illustrated. However, the shift amount D is not particularly limited. The shift amount D may be determined to be a value within the range that satisfies 0 < D < P / 2. Specific examples thereof will be described below.

[0095] As shown in FIG. 11, in the wire fin group 340 according to the present embodiment, the shift amount D is set to a distance that is one-fourth of the array pitch P (D = P / 4).

[0096] FIG. 12 shows only the second wire fin group 330 extracted from the wire fin group 340 shown in FIG. 11 for easy understanding.

[0097] According to the present embodiment, compared with the configurations shown in FIGS. 9 and 10, the overlapping portion in the Y-axis direction between the wire fin 310 and another wire fin 310 adjacent to the wire fin 310 in the Y-axis direction is reduced. As a result, compared with the case of adopting the configurations shown in FIGS. 9 and 10, the development of the temperature boundary layer in the direction of the coolant flow is suppressed. By suppressing the development of the temperature boundary layer, the cooling capacity of the cooler 500 is improved.

[0098] Note that the shift amount D may be set to one-eighth of the array pitch P (D = P / 8), or may be set to one-sixteenth of the array pitch P (D = P / 16).

[0099] [Embodiment 3] FIG. 5 illustrates a configuration in which the first wire fin group 320 and the second wire fin group 330 are alternately arranged in the Y-axis direction. The wire fin group 340 may have only one set of the first wire fin group 320 and the second wire fin group 330 adjacent to each other in the Y-axis direction. Specific examples thereof will be described below.

[0100] Fig. 13 shows a wire fin group 340 according to this embodiment. In this wire fin group 340, a first wire fin group 320 and a second wire fin group 330 are arranged adjacent to each other in the Y-axis direction, similar to the configuration shown in Fig. 5. However, the wire fin group 340 according to this embodiment has only one pair of the first wire fin group 320 and the second wire fin group 330 adjacent to each other in the Y-axis direction.

[0101] Hereinafter, the edge of the flow path defining region 121 that is closer to the coolant inlet 410 in the Y-axis direction will be referred to as one Y-axis edge 121c. Also, the edge of the flow path defining region 121 that is closer to the coolant outlet 420 in the Y-axis direction will be referred to as the other Y-axis edge 121d. Also, the center part of the flow path defining region 121 in the Y-axis direction will be referred to as a Y-axis center 121e.

[0102] The first wire fin group 320 according to this embodiment covers a portion of the flow path defining region 121 between the Y-axis center 121e and one Y-axis edge 121c. The second wire fin group 330 according to this embodiment covers a portion of the flow path defining region 121 between the Y-axis center 121e and the other Y-axis edge 121d.

[0103] As described above, the coolant normally flows through a path that minimizes pressure loss. However, the coolant that flows in from the coolant inlet 410 tends to move in a straight line due to inertia upstream of the Y-axis center 121e. This makes it less likely that most of the coolant will flow through the first space to the side of the first wire fin group 320, and a sufficient flow rate of the coolant passes through the first wire fin group 320.

[0104] If all the wire fins 310 were inclined in the same direction, the coolant would tend to be biased toward the region without wire fins 310, i.e., the first space, as it moves downstream. However, in this embodiment, the communication of the first space in the Y-axis direction is blocked by the second wire fin group 330 downstream of the Y-axis center 121e. Therefore, even in the portion close to the Y-axis center 121e, the flow of the coolant is unlikely to be extremely biased toward the first space. In other words, a sufficient flow rate of the coolant passes through the downstream portion of the first wire fin group 320 close to the Y-axis center 121e.

[0105] A second space is present to the side of second wire fin group 330, but the upstream side of the second space is blocked by first wire fin group 320. The presence of upstream first wire fin group 320 distributes the flow of coolant within the XZ plane, so the flow of coolant is unlikely to be excessively biased toward the second space downstream of Y-axis direction center 121e. A sufficient amount of coolant passes through second wire fin group 330 and is discharged from coolant outlet 420.

[0106] As a result, according to this embodiment as well, the deviation of the flow rate of the coolant in the XZ plane is suppressed over the entire length of the flow path defining region 121 in the Y-axis direction.

[0107] Furthermore, in this embodiment, the number of pairs of first wire fin groups 320 and second wire fin groups 330 adjacent to each other in the Y-axis direction is limited to the minimum of one pair. In other words, the number of times the tilt direction of wire fins 310 reverses is limited to one. Therefore, pressure loss in gap 400a can be reduced compared to a configuration in which first wire fin groups 320 and second wire fin groups 330 are alternately arranged in the Y-axis direction, i.e., a configuration in which the tilt direction of wire fins 310 reverses multiple times.

[0108] [Embodiment 4] In any of the configurations of the first to third embodiments described above, the area of ​​the flow path defining region 121 that is covered by the wire fin group 340 may be limited to match the shape of the semiconductor module 600. A specific example of this will be described below.

[0109] 14 shows a semiconductor device 700 according to this embodiment. Two semiconductor modules 600 are attached to the outer surface 110 of the base unit 100 with a gap between them in the Y-axis direction. Therefore, the outer surface 110 of the base unit 100 has a covered area that is covered by the semiconductor modules 600 and an uncovered area that is exposed to the outside. The uncovered area refers to the area between the two semiconductor modules 600.

[0110] Hereinafter, a projection region of the flow path defining region 121 of the inner surface 120, obtained by projecting the covered region onto the inner surface 120 in the Z-axis direction, will be referred to as a first projection region R1. Also, a projection region of the flow path defining region 121 of the inner surface 120, obtained by projecting the uncovered region onto the inner surface 120 in the Z-axis direction, will be referred to as a second projection region R2.

[0111] In this embodiment, the wire fin group 340 is arranged only in the first projection region R1 of the flow path defining region 121 of the inner surface 120. The wire fin group 340 is not provided in the second projection region R2 of the flow path defining region 121 of the inner surface 120. In other words, the second projection region R2 is exposed to the coolant flow path 400. Note that a portion of the first projection region R1 may be exposed to the coolant flow path 400.

[0112] According to the present embodiment, the wire fin group 340 is not arranged in the second projection region R2, and therefore the number of wire fins 310 constituting the wire fin group 340 can be reduced accordingly. Because the number of wire fins 310 can be reduced, pressure loss in the coolant flow path 400 is reduced, and manufacturing costs are also reduced. Nevertheless, because the wire fin group 340 is arranged in the first projection region R1 located directly behind the semiconductor module 600, the effect of cooling the semiconductor module 600 is unlikely to be impaired.

[0113] [Embodiment 5] In any of the configurations of the first to fourth embodiments described above, the distance in the Y-axis direction between the first wire fin group 320 and the second wire fin group 330 that are adjacent in the Y-axis direction may be set to be larger than the distance in the Y-axis direction between the wire fins 310 that are adjacent in the Y-axis direction in each of the first wire fin group 320 and the second wire fin group 330. Specific examples of this will be described below.

[0114] 15 shows a semiconductor device 700 according to this embodiment. In the first wire fin group 320, the distance in the Y-axis direction between adjacent wire fins 310 in the Y-axis direction is defined as F. In this embodiment, the value of the distance F is common to all of the first wire fin groups 320 that make up the wire fin group 340.

[0115] In this embodiment, the distance in the Y-axis direction between adjacent wire fins 310 in the second wire fin group 330 is also set to F. The value of the distance F is common to all of the second wire fin groups 330 that make up the wire fin group 340.

[0116] Meanwhile, the distance in the Y-axis direction between the first wire fin group 320 and the second wire fin group 330 adjacent to each other in the Y-axis direction is defined as G. In this embodiment, the value of the distance G is common to all pairs of the first wire fin group 320 and the second wire fin group 330 adjacent to each other in the Y-axis direction.

[0117] In this embodiment, the distance G in the Y-axis direction between the first wire fin group 320 and the second wire fin group 330 adjacent to each other in the Y-axis direction is set to be larger than the distance F in the Y-axis direction between the wire fins 310 adjacent to each other in the Y-axis direction in each of the first wire fin group 320 and the second wire fin group 330 (G>F).

[0118] As described above, the flow of the coolant is turbulent between the first wire fin group 320 and the second wire fin group 330 that are adjacent in the Y-axis direction. In this embodiment, by setting the interval G larger than the interval F, it is possible to reduce the pressure loss that accompanies the formation of turbulence, compared to a configuration in which the interval G is equal to or smaller than the interval F (G≦F).

[0119] Note that almost no turbulence is formed between adjacent wire fins 310 in the Y-axis direction in each of the first wire fin group 320 and the second wire fin group 330. Therefore, even if the value of the spacing F is set to a small value, the pressure loss is unlikely to increase. Therefore, by adjusting the spacing F to a small value, it is possible to ensure a sufficient density of the arrangement of the wire fins 310 in the Y-axis direction.

[0120] The above has described embodiments 1 to 5. The following variations are also possible.

[0121] 5 and 13 show an example of a wire fin 310 whose cross section is elongated in the width direction over its entire length (hereinafter referred to as an elongated shape). The wire fin 310 may have an elongated cross section only in the loop-shaped portion 31. That is, the cross section of the joint portion 311 does not have to be elongated. Furthermore, the wire fin 310 may be a linear wire fin whose cross section has the same width and thickness, or a thick wire fin whose cross section has a thickness greater than its width.

[0122] 1 to 15 also illustrate an XYZ Cartesian coordinate system having an imaginary Y-axis parallel to the length direction of the coolant flow path 400 at the position of the inner surface 120 and an imaginary X-axis perpendicular to the imaginary Y-axis. When the direction in which the wire fins 310 extend is defined as the direction of the imaginary X-axis, the imaginary X-axis does not necessarily have to be perpendicular to the imaginary Y-axis. In that case, it is sufficient that the imaginary X-axis is parallel to the inner surface 120, which is a plane, and intersects with the imaginary Y-axis.

[0123] 1 to 3, 14, and 15 show examples of two semiconductor modules 600 lined up in the Y-axis direction. The number of semiconductor modules 600 attached to the outer surface 110 is not particularly limited. The number of semiconductor modules 600 attached to the outer surface 110 may be one, or may be three or more. Furthermore, on the outer surface 110, a plurality of semiconductor modules 600 may be lined up in a row in the X-axis direction, or a plurality of semiconductor modules 600 may be lined up in a matrix in the X-axis and Y-axis directions.

[0124] Various aspects of the present disclosure are described below. (Appendix 1) a plate-shaped base portion having an outer surface to which an object to be cooled is attached and an inner surface opposite to the outer surface; a case portion disposed opposite the inner surface of the base portion and defining, together with the base portion, a coolant flow path that is a flow path of a coolant for cooling the object to be cooled; a heat sink provided in a flow path defining region of the inner surface of the base portion facing the coolant flow path, the heat sink transferring heat of the object to be cooled to the coolant flowing through the coolant flow path; Equipped with When an imaginary Y-axis that is parallel to the length direction of the coolant flow path at the position of the inner surface and an imaginary X-axis that is parallel to the inner surface and intersects with the imaginary Y-axis are defined, The heat sink is a wire fin group in which a plurality of wire fins each extending in an X-axis direction that is a direction of the imaginary X-axis are arranged side by side in a Y-axis direction that is a direction of the imaginary Y-axis; and Each of the wire fins comprises: a plurality of junctions arranged at intervals in the X-axis direction, each junction being joined to the flow path defining region of the inner surface; a plurality of loop-shaped portions each connecting the joint portions adjacent to each other in the X-axis direction, the plurality of loop-shaped portions through which the cooling liquid passes; and The wire fin group includes: a first wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the first wire fin group is inclined in a positive direction of the X-axis, which is a direction from one end edge of the flow path defining region to the other end edge in the X-axis direction; a second wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the second wire fin group is inclined in a negative direction of the X-axis, which is a direction from the other end edge toward the one end edge of the flow path defining region; Contains, The first wire fin group and the second wire fin group are arranged adjacent to each other in the Y-axis direction. cooler. (Appendix 2) the cooler defines a coolant inlet through which the coolant is introduced into the coolant flow path and a coolant outlet through which the coolant is discharged from the coolant flow path; one of the first wire fin group and the second wire fin group covers a portion of the flow path defining region between a center in the Y-axis direction and an edge closer to the coolant inlet in the Y-axis direction, the other of the first wire fin group and the second wire fin group covers a portion of the flow path defining region between a center in the Y-axis direction and an edge closer to the coolant outlet in the Y-axis direction. Appendix 1 Cooler. (Appendix 3) In the wire fin group, the first wire fin groups and the second wire fin groups are alternately arranged in the Y-axis direction, and a plurality of pairs of the first wire fin groups and the second wire fin groups adjacent to each other in the Y-axis direction are formed. Appendix 1 Cooler. (Appendix 4) In each of the first wire fin group and the second wire fin group, the joints of the wire fins arranged adjacent to each other in the Y-axis direction are distributed in a staggered pattern in the flow path defining region of the inner surface; A cooler according to any of the appendices 1 to 3. (Appendix 5) In each of the wire fins, the bonding portions are periodically arranged in the X-axis direction, an arrangement pitch representing the distance in the X-axis direction between the joints adjacent in the X-axis direction is equal for all the wire fins in the wire fin group; In each of the first wire fin group and the second wire fin group, the arrangement of the plurality of bonding portions constituting the wire fin is shifted in the X-axis direction by a predetermined shift amount with respect to the arrangement of the plurality of bonding portions constituting the wire fin adjacent to the wire fin in the Y-axis direction, the shift amount is common between a pair of the wire fins adjacent to each other in the Y-axis direction and another pair of the wire fins adjacent to each other in the Y-axis direction; Appendix 4 Cooler. (Appendix 6) The shift amount is half the arrangement pitch. Appendix 5 Cooler. (Appendix 7) The amount of shift is less than half the arrangement pitch. Appendix 5 Cooler. (Appendix 8) the outer surface has a covered area that is covered by the object to be cooled and an uncovered area that is exposed to the outside, the wire fin group is disposed in a first projected region of the flow path defining region of the inner surface, the first projected region being obtained by projecting the covered region onto the inner surface in a thickness direction of the base portion; a second projected area, which is a projection of the uncovered area onto the inner surface in a thickness direction of the base portion, of the flow path defining area of ​​the inner surface, is exposed to the coolant flow path; A cooler according to any of the appendices 1 to 7. (Appendix 9) the distance in the Y-axis direction between the first wire fin group and the second wire fin group that are adjacent to each other in the Y-axis direction is larger than the distance in the Y-axis direction between the wire fins that are adjacent to each other in the Y-axis direction in each of the first wire fin group and the second wire fin group; A cooler according to any of the appendices 1 to 8. (Appendix 10) a dimension of the flow path defining region in a direction perpendicular to the Y-axis direction is smaller than a dimension of the coolant flow path in the Y-axis direction; A cooler according to any of the appendices 1 to 9. (Appendix 11) Each of the wire fins has a width parallel to the Y-axis direction and a thickness perpendicular to the width; a cross section of at least the portion of each of the wire fins constituting the loop-shaped portion, the cross section being parallel to the width direction and the thickness direction, has an elongated shape in the width direction; A cooler according to any of the appendices 1 to 10. (Appendix 12) A cooler according to any one of appendices 1 to 11; a semiconductor module as the object to be cooled attached to the outer surface; A semiconductor device comprising: [Explanation of symbols]

[0125] 100 base portion, 110 outer surface, 120 inner surface, 121 flow path defining region, 121a one end edge in the X-axis direction, 121b other end edge in the X-axis direction, 121c one end edge in the Y-axis direction, 121d other end edge in the Y-axis direction, 121e center in the Y-axis direction, 200 case portion, 210 coolant inlet pipe, 220 coolant outlet pipe, 300 heat sink, 310 wire fin, 310A first wire fin, 310B second wire fin, 311 joint portion, 312 loop portion, 312a rising portion, 312b top portion, 320 first wire fin group, 330 second wire fin group, 340 wire fin group, 400 coolant flow path, 400a gap, 410 coolant inlet, 420 coolant outlet, 500 cooler, 600 Semiconductor module (object to be cooled), 700 semiconductor device, R1 first projection area, R2 second projection area.

Claims

1. a plate-shaped base portion having an outer surface to which an object to be cooled is attached and an inner surface opposite to the outer surface; a case portion disposed opposite the inner surface of the base portion and defining, together with the base portion, a coolant flow path that is a flow path of a coolant for cooling the object to be cooled; a heat sink provided in a flow path defining region of the inner surface of the base portion facing the coolant flow path, the heat sink transferring heat of the object to be cooled to the coolant flowing through the coolant flow path; Equipped with When an imaginary Y-axis that is parallel to the length direction of the coolant flow path at the position of the inner surface and an imaginary X-axis that is parallel to the inner surface and intersects with the imaginary Y-axis are defined, The heat sink is a wire fin group in which a plurality of wire fins each extending in an X-axis direction that is a direction of the imaginary X-axis are arranged side by side in a Y-axis direction that is a direction of the imaginary Y-axis; and Each of the wire fins comprises: a plurality of junctions arranged at intervals in the X-axis direction, each junction being joined to the flow path defining region of the inner surface; a plurality of loop-shaped portions each connecting the joint portions adjacent to each other in the X-axis direction, the plurality of loop-shaped portions through which the cooling liquid passes; and The wire fin group includes: a first wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the first wire fin group is inclined in a positive direction of the X-axis, which is a direction from one end edge of the flow path defining region toward the other end edge in the X-axis direction; a second wire fin group consisting of a plurality of the wire fins arranged adjacent to each other in the Y-axis direction, wherein the loop-shaped portion of each of the wire fins constituting the second wire fin group is inclined in a negative direction of the X-axis, which is a direction from the other end edge toward the one end edge of the flow path defining region; Contains, The first wire fin group and the second wire fin group are arranged adjacent to each other in the Y-axis direction. cooler.

2. the cooler defines a coolant inlet through which the coolant is introduced into the coolant flow path and a coolant outlet through which the coolant is discharged from the coolant flow path; one of the first wire fin group and the second wire fin group covers a portion of the flow path defining region between a center in the Y-axis direction and an edge closer to the coolant inlet port in the Y-axis direction, the other of the first wire fin group and the second wire fin group covers a portion of the flow path defining region between a center in the Y-axis direction and an edge closer to the coolant outlet in the Y-axis direction. The cooler of claim 1 .

3. In the wire fin group, the first wire fin groups and the second wire fin groups are alternately arranged in the Y-axis direction, and a plurality of pairs of the first wire fin groups and the second wire fin groups adjacent to each other in the Y-axis direction are formed. The cooler of claim 1 .

4. In each of the first wire fin group and the second wire fin group, the joints of the plurality of wire fins arranged adjacent to each other in the Y-axis direction are distributed in a staggered pattern in the flow path defining region of the inner surface; The cooler of claim 1 .

5. In each of the wire fins, the bonding portions are periodically arranged in the X-axis direction, an arrangement pitch representing a distance in the X-axis direction between the joints adjacent in the X-axis direction is equal for all the wire fins in the wire fin group; In each of the first wire fin group and the second wire fin group, the arrangement of the plurality of bonding portions constituting the wire fin is shifted in the X-axis direction by a predetermined shift amount with respect to the arrangement of the plurality of bonding portions constituting the wire fin adjacent to the wire fin in the Y-axis direction, the shift amount is common between the pair of wire fins adjacent to each other in the Y-axis direction and another pair of wire fins adjacent to each other in the Y-axis direction; The cooler of claim 4.

6. The shift amount is half the arrangement pitch. The cooler according to claim 5 .

7. The amount of shift is less than half the arrangement pitch. The cooler according to claim 5 .

8. the outer surface has a covered area that is covered by the object to be cooled and an uncovered area that is exposed to the outside, the wire fin group is disposed in a first projected region of the flow path defining region of the inner surface, the first projected region being obtained by projecting the covered region onto the inner surface in a thickness direction of the base portion, a second projected region of the flow path defining region of the inner surface, the second projected region being obtained by projecting the uncovered region onto the inner surface in a thickness direction of the base portion, the second projected region being exposed to the coolant flow path; The cooler of claim 1 .

9. a distance in the Y-axis direction between the first wire fin group and the second wire fin group that are adjacent to each other in the Y-axis direction is larger than a distance in the Y-axis direction between the wire fins in each of the first wire fin group and the second wire fin group that are adjacent to each other in the Y-axis direction; The cooler of claim 1 .

10. a dimension of the flow path defining region in a direction perpendicular to the Y-axis direction is smaller than a dimension of the coolant flow path in the Y-axis direction; The cooler of claim 1 .

11. Each of the wire fins has a width parallel to the Y-axis direction and a thickness perpendicular to the width, a cross section of at least the portion of each of the wire fins constituting the loop-shaped portion, the cross section being parallel to the width direction and the thickness direction, has an elongated shape in the width direction; The cooler of claim 1 .

12. A cooler according to any one of claims 1 to 11; a semiconductor module as the object to be cooled attached to the outer surface; A semiconductor device comprising:

Images