Cooler and semiconductor device

Abstract

The cooler (1A) is provided with a housing (10A) and a base, the housing has, inside: a bottom surface portion of a flow path through which a refrigerant flows; a supply groove provided at an upstream end portion of the bottom surface portion, recessed from the upstream end portion, which supplies the refrigerant flowing inside to the flow path; and a discharge groove provided at a downstream end portion of the bottom surface portion, recessed from the downstream end portion, which causes the refrigerant flowing from the flow path to flow inside and discharge, the base is provided with a heat generating body at one face side, and causes the other face to oppose the bottom surface portion of the flow path to cover the bottom surface portion, the supply groove, and the discharge groove, and a plurality of fins (30) are arranged at the other face side.

Description

Technical Field

[0001] This disclosure relates to coolers and semiconductor devices. Background Technology

[0002] In the realm of coolers, there exist coolers that use refrigerant to cool heat-generating elements, such as semiconductor components.

[0003] For example, Patent Document 1 discloses a cooler comprising: a housing having a box shape with a top plate side opening; and a base plate having a semiconductor element disposed on one side and a plurality of fins disposed on the other side, the base plate closing the opening of the housing when the other side faces the interior space of the housing. This cooler releases heat transferred from the semiconductor element to the plurality of fins back to the refrigerant by allowing refrigerant to flow within the interior space of the housing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-137411 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The cooler described in Patent Document 1 has the following features inside its housing: a bottom portion that faces a base plate to form a flow path; a supply tank adjacent to the upstream end of the bottom portion for supplying refrigerant into the flow path; and a discharge tank adjacent to the downstream end of the bottom portion for discharging refrigerant from the flow path. Thus, in this cooler, the refrigerant flows extensively throughout the entire flow path, thereby improving cooling efficiency.

[0009] Furthermore, in the cooler described in Patent Document 1, multiple fins are provided on a region on another side of the base plate opposite the bottom surface of the aforementioned flow path. To improve cooling efficiency, when viewed from a direction perpendicular to the other side of the base plate, the region where these fins are provided overlaps with the region on one side of the base plate where semiconductor elements are located. As a result, the bottom surface of the flow path is sometimes larger than the region on the other side of the base plate where semiconductor elements are located. Consequently, the cooler itself is sometimes larger than the semiconductor elements being cooled.

[0010] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a cooler and a semiconductor device that have high cooling efficiency and are miniaturized relative to the heat-generating element being cooled.

[0011] Methods for solving problems

[0012] To achieve the above objective, a cooler according to the present disclosure includes a housing and a base. The housing internally has: a bottom surface portion of a flow passage, which has a rectangular shape with two opposite sides facing upstream and downstream, and through which a refrigerant flows; a supply groove, which is provided at the upstream end of the bottom surface portion, is recessed relative to the upstream end, and supplies the refrigerant flowing inside to the flow passage; and a discharge groove, which is provided at the downstream end of the bottom surface portion, is recessed relative to the downstream end, and allows the refrigerant flowing in from the flow passage to flow inside and be discharged. The base has a heating element disposed on one surface side, covers the bottom surface portion, the supply groove, and the discharge groove with the other surface facing the bottom surface portion of the flow passage, and a plurality of fins are arranged on the other surface side.

[0013] The plurality of fins are disposed in a flow passage region that is at least the flow passage region of the other surface of the base that faces the bottom surface portion, and that is a flow passage region overlapping with the region where the heating element is disposed on the one surface of the base when viewed from a direction perpendicular to the other surface.

[0014] Further, the plurality of fins are arranged in the extending direction of the flow passage from the upstream end to the downstream end of the bottom surface portion, and when viewed from the direction perpendicular to the other surface, the plurality of fins are arranged in the width direction of the flow passage orthogonal to the extending direction of the flow passage.

[0015] Furthermore, where D1 is defined as the distance from a reference line set on the bottom surface portion and extending in the width direction to the upstream end of the bottom surface portion, D2 is defined as the distance from the reference line to the upstream end of the first fin arranged at the most upstream side among the plurality of fins, and D3 is defined as the distance from the end in the width direction of the flow passage to the second fin closest to the end among the plurality of fins, the cooler satisfies the relational expression of D1-D2<D3.

[0016] Alternatively, where D4 is defined as the distance from the reference line to the downstream end of the bottom surface portion, and D5 is defined as the distance from the reference line to the downstream end of the third fin arranged at the most downstream side among the plurality of fins, the cooler satisfies the relational expression of D4-D5<D3.

[0017] Advantageous Effects of Invention

[0018] According to the configuration of the present disclosure, the cooler satisfies the above relational expression of D1-D2<D3 or the relational expression of D4-D5<D3. Therefore, in the cooler, the flow passage region where the fins are arranged can be set as small as possible on the bottom surface portion of the flow passage. As a result, the cooler has high cooling efficiency, and is compact relative to the heating element that is the object to be cooled. Description of Related Drawings

[0019] Figure 1 is a perspective view of the cooler according to Embodiment 1 of the present disclosure.

[0020] Figure 2 This is a component structure diagram of the cooler according to Embodiment 1 of this disclosure.

[0021] Figure 3 yes Figure 1 The cross-sectional view shown by the cut line III-III.

[0022] Figure 4 This is a conceptual diagram showing the shape of the groove formed on the housing of the cooler according to Embodiment 1 of this disclosure.

[0023] Figure 5 yes Figure 1 The cross-sectional view shown is the VV cut line.

[0024] Figure 6 This is a perspective view of the base plate of the cooler according to Embodiment 1 of this disclosure.

[0025] Figure 7 yes Figure 6 An enlarged view of region VII shown.

[0026] Figure 8 This is a left-side view of the base plate of the cooler according to Embodiment 1 of this disclosure.

[0027] Figure 9 This is a bottom view of the base plate of the cooler according to Embodiment 1 of this disclosure.

[0028] Figure 10 yes Figure 9 A magnified view of region X shown.

[0029] Figure 11 This is a top view showing the positional relationship between the flat surface portion, the groove and the fins provided on the housing of the cooler of Embodiment 1 of this disclosure.

[0030] Figure 12 This is a cross-sectional view of the cooler according to Embodiment 2 of this disclosure.

[0031] Figure 13 This is a top view showing the positional relationship between the flat surface portion, the groove and the fins provided on the housing of the cooler of Embodiment 2 of this disclosure.

[0032] Figure 14 This is a cross-sectional view of a modified example of the cooler according to Embodiment 2 of this disclosure.

[0033] Figure 15 This is a perspective view of the cooler according to Embodiment 3 of this disclosure.

[0034] Figure 16 yes Figure 15 The cross-sectional view shown is along the XVI-XVI cut line.

[0035] Figure 17 This is a cross-sectional view of the cooler according to Embodiment 4 of this disclosure.

[0036] Figure 18 This is a cross-sectional view of a first modified example of a groove formed on the housing of the cooler according to Embodiment 1 of this disclosure.

[0037] Figure 19 This is a cross-sectional view of a second variation of the groove formed on the housing of the cooler according to Embodiment 1 of this disclosure.

[0038] Figure 20 This is a cross-sectional view of a third variation of the groove formed on the housing of the cooler according to Embodiment 1 of this disclosure.

[0039] Figure 21 This is a cross-sectional view of a fourth variation of the groove formed on the housing of the cooler according to Embodiment 1 of this disclosure.

[0040] Figure 22 This is a top view showing the positional relationship between the end of the flat surface portion of the shell of the cooler of Embodiment 1 of this disclosure and a modified example of the fins. Detailed Implementation

[0041] Hereinafter, the cooler and semiconductor device according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same or equivalent parts are labeled with the same reference numerals. Additionally, in the orthogonal coordinate system XYZ shown in the drawings, the left-right direction is defined as the X-axis, the front-back direction is defined as the long side of the rectangular base plate of the cooler pointing left-right and the short side pointing forward-backward, and the direction orthogonal to the X-axis and Y-axis is defined as the Z-axis. This coordinate system will be appropriately referenced in the following description.

[0042] (Implementation Method 1)

[0043] The cooler of Embodiment 1 is a device that cools a heating element by using a refrigerant to cool multiple fins mounted on a base plate on which the heating element to be cooled is mounted. Furthermore, this cooler is miniaturized while improving cooling efficiency by arranging these fins in specific positions. Hereinafter, this cooler will be described in detail using the case where the heating element is a power module, which is a type of semiconductor device. First, referring to… Figures 1 to 8 The overall structure of the cooler will be explained.

[0044] Figure 1 This is a perspective view of the cooler 1A according to Embodiment 1. Figure 2 This is a structural diagram of the components of cooler 1A. Figure 3 yes Figure 1The cross-sectional view shown by the cut line III-III. Figure 4 This is a conceptual diagram showing the shape of the grooves 12 and 13 formed on the housing of the cooler 1A. Figure 5 yes Figure 1 The cross-sectional view shown is the VV cut line. Figure 6 This is a perspective view of the base plate 20A of the cooler 1A. Figure 7 yes Figure 6 An enlarged view of region VII shown. Figure 8 This is the left side view of base plate 20A.

[0045] In addition, Figure 2 For ease of understanding, the diagram also illustrates the fins 30 located on the lower surface of the base plate 20A, i.e., the -Z side. Additionally, in Figure 3 The size of fin 30 is emphasized. Additionally, in... Figures 6-8 The diagram shows the base plate 20A with its -Z surface facing upwards.

[0046] like Figure 1 As shown, the cooler 1A includes: a housing 10A for refrigerant flow; and a base plate 20A mounted on the housing 10A, which carries and cools multiple power modules 2 that are being cooled.

[0047] like Figure 2 As shown, the housing 10A has the shape of a cuboid, more specifically a rectangular thick plate. Furthermore, the housing 10A is arranged with its plate surface facing vertically. A recess 11 is formed in the central portion of the upper surface of the housing 10A. This recess 11 is rectangular in shape with its long side facing horizontally when viewed from above. Moreover, grooves 12 and 13, which are separated and parallel to each other in the front-rear direction, and a flat surface portion 14 disposed between these grooves 12 and 13 are formed in the recess 11.

[0048] The trough 12, also known as a manifold, distributes and supplies refrigerant to the entire flow path formed by the flat surface portion 14 when refrigerant is supplied. In detail, the trough 12 extends along the rear end of the flat surface portion 14 in the left-right direction (X-direction) to supply refrigerant to the entire flat surface portion 14. The length of the trough 12 is the same as the length of the flat surface portion 14 in the X-direction. Furthermore, a through-shell 10A is formed on the inner wall of the trough 12 at the X-end. Figure 3 The through hole 121 shown has a [missing information - likely a number or designation]. Figure 2 The pipe fitting 122 shown.

[0049] Pipe fitting 122 connects to piping extending from an external device (not shown). Furthermore, pipe fitting 122 supplies refrigerant to tank 12 by supplying refrigerant such as water or ethylene glycol from this external device. In detail, Figure 3 The through hole 121 shown is formed at the bottom side of the opening of the tank 12, through which the pipe joint 122 allows the refrigerant to flow into the bottom side of the tank 12.

[0050] like Figure 3 As shown, the groove 12 is larger than the pipe joint 122 in cross-section. Therefore, the groove 12 reduces the pressure loss when the refrigerant flows in from the pipe joint 122.

[0051] In addition, such as Figure 3 and Figure 4 As shown, the groove 12 has a shape composed of a combination of rectangles and circles when viewed in section. More specifically, as... Figure 3 As shown, in a YZ section view, the groove 12 is formed by overlapping a rectangle with its long side facing the Z direction and its short side facing the Y direction with a circle having a diameter D6. This diameter D6 is smaller than the length L1 of the long side of the rectangle and larger than the length L2 of the short side. Furthermore, in a YZ section view, the groove 12 is tangent to both the -Y side (extending along the long side of the rectangle) and the -Z side (extending along the short side of the rectangle). Moreover, the groove 12 maintains this cross-sectional shape and extends straight in the X direction.

[0052] In the tank 12, the portion having such a shape that is circular in YZ section allows the refrigerant supplied from the pipe joint 122 to flow smoothly into the +X side, i.e. the inner side, of the tank 12.

[0053] Furthermore, the rectangular portion of tank 12 in YZ section allows refrigerant flowing into the bottom of tank 12 through pipe joint 122 to flow towards the opening side of the rectangle along its longer side. Specifically, in tank 12, the length L1 of the longer side of the YZ section rectangle is greater than the length L2 of the shorter side. Additionally, the -Y and +Y sides of the YZ section rectangle extend straight in the Z direction. As a result, in tank 12, as the refrigerant flows along the -Y and +Y sides, it is easily homogenized towards the +X direction of tank 12.

[0054] Furthermore, the groove 12 has a circular portion at the bottom when viewed in YZ section. As a result, the width of the opening in the Y direction when viewed in YZ section is smaller than the width of the circular portion at the bottom in the Y direction. Consequently, in the groove 12, a greater resistance is exerted on the refrigerant as it flows from the bottom to the opening. Therefore, in the groove 12, the refrigerant easily spreads throughout the entire X direction and is less likely to become uneven in the X direction.

[0055] On the other hand, such as Figure 3As shown, a flat surface portion 14 is provided on the +Y side of the opening of the groove 12.

[0056] The flat surface portion 14 is the bottom portion of the flow path through which the refrigerant flows in order to cool the plurality of fins 30 described later. Figure 2 The fins 30 shown are arranged in an elongated rectangular region A1 of the base plate 20A, which has the same configuration shape as the power modules 2, to cool the multiple power modules 2 configured in an elongated rectangular shape. The flat surface portion 14 is formed into an elongated rectangular shape of the same shape and size as this region A1 for cooling the fins 30. Furthermore, the long side of the flat surface portion 14 faces the X direction. The flat surface portion 14 is adjacent to the opening of the slot 12 in the Y direction, which is the short side direction. As a result, refrigerant flows from the slot 12 into the flat surface portion 14 at the -Y end of the slot 12. Thus, the flat surface portion 14 functions as a flow path with the -Y end as its upstream end.

[0057] Furthermore, the flat surface portion 14 can be any rectangle corresponding to the symmetrical configuration shape of the cooling system, for example, it can also be a square. Here, a rectangle refers to a quadrilateral with all four angles equal.

[0058] Furthermore, the flat surface portion 14 is formed flat to facilitate the smooth flow of refrigerant. Additionally, the flat surface portion 14 contacts the fins 30 and exchanges heat with them, therefore it is made of a material with high thermal conductivity. During refrigerant flow, the flat surface portion 14 releases the heat transferred from the fins 30 back to the refrigerant. Thus, the flat surface portion 14 efficiently cools the fins 30.

[0059] And, as Figure 3 As shown, by placing the base plate 20A on top of the housing 10A, the flat surface portion 14 is positioned opposite the base plate 20A. As a result, the flat surface portion 14 forms a flow path for refrigerant flow between itself and the base plate 20A. The size of the gap between the flat surface portion 14 and the base plate 20A, i.e., the height H1 of the flow path, is smaller than the depth of the groove 12. That is, the height H1 of the flow path is smaller than the length L1 of the long side of the YZ cross-sectional rectangle of the groove 12. Furthermore, the height H1 of the flow path is smaller than the width of the groove 12. That is, the height H1 of the flow path is smaller than the length L2 of the short side of the YZ cross-sectional rectangle of the groove 12. Therefore, the resistance to refrigerant flowing into the groove 12 in the flow path is increased. As a result, refrigerant is more easily distributed throughout the flow path as it flows in. This results in a more uniform refrigerant flow rate in the flow path. Additionally, the smaller height H1 in the flow path results in a faster refrigerant flow velocity. As a result, the fins 30 have high cooling efficiency in the flow path.

[0060] On the other hand, a groove 13 is opened at the downstream end of the flow path, that is, at the +Y end of the flat surface portion 14. Thus, when the refrigerant flows through the flat surface portion 14, the refrigerant flows out into the groove 13.

[0061] The trough 13, also known as a manifold, collects the refrigerant flowing in from the flat surface portion 14 and discharges it outside the casing 10A. Detailed explanation of the structure: the trough 13 collects the refrigerant from the flow path formed by the flat surface portion 14, and therefore opens on the +Y side of the flat surface portion 14. Furthermore, as... Figure 2 As shown, since the +Y end of the flat surface portion 14 extends straight in the X direction, the groove 13 also extends in the X direction. Furthermore, the X-direction length of the groove 13 is the same as the X-direction length of the flat surface portion 14. Thus, the groove 13 collects refrigerant from the entire flow path formed by the flat surface portion 14.

[0062] like Figure 3 As shown, groove 13, in cross-section, has a shape symmetrical to groove 12 described above. Specifically, the shape of groove 13 in YZ cross-section is symmetrical to the shape of groove 12 in YZ cross-section about the center line L3 of the housing 10A, which is parallel to the Z-axis and passes through the center between grooves 12 and 13. As a result, the effect of groove 13 on the refrigerant is the same as that of groove 12. Therefore, descriptions of the shape and size of groove 13 and its effect on the refrigerant are omitted.

[0063] To allow refrigerant to be discharged to the outside, a through hole 131 is formed on the inner wall of the +X end of the tank 13, penetrating the housing 10A. Furthermore, a [missing information - likely a component or material] is embedded in this through hole 131. Figure 2 Pipe fitting 132 is shown. Pipe fitting 132 connects to piping extending from an external device (not shown). As a result, the refrigerant collected in tank 13 returns to the external device through pipe fitting 132.

[0064] The recess 11 of the housing 10A has grooves 12 and 13 and a flat surface portion 14 with such a structure. Furthermore, the refrigerant flows within these grooves 12, 13, and flat surface portion 14. To seal the refrigerant into the recess 11, as... Figure 2 and Figure 3 As shown, the recess 11 is covered by the base plate 20A.

[0065] On one side of the base plate 20A, namely the +Z side, multiple symmetrically cooled power modules 2 are arranged in a row. Specifically, on the +Z side of the base plate 20A, six power modules 2 are arranged in a row in the X direction.

[0066] Furthermore, power module 2 refers to a component composed of power semiconductor elements that control and convert electricity. Also, although not shown, power module 2, when mounted on the +Z side of base plate 20A, is connected via wires to components arranged along the Y direction, such as capacitors.

[0067] Furthermore, the base plate 20A is made of a metal with high thermal conductivity to facilitate heat transfer when the power modules 2 are in operation. Thus, the base plate 20A transfers heat from the power modules 2 mounted on the +Z plane to the -Z plane.

[0068] Furthermore, on the -Z side of the base plate 20A, in order to dissipate the heat of the power module 2, such as... Figure 3 and Figure 5 As shown, multiple fins 30 are provided.

[0069] Each fin 30 is formed of the same material as the base plate 20A. Therefore, each fin 30, like the base plate 20A, has high thermal conductivity. As a result, heat from the power module 2 is easily transferred to each fin 30. Furthermore, as... Figure 6 and Figure 7 As shown, each fin 30 is formed in the shape of a regular hexagonal prism, with the prism extending along the -Z direction. The height of these fins 30 is the same as the height H1 of the flow path described above. Furthermore, it is not necessary for all fins 30 to be the same height H1 as the flow path; it is sufficient that most of the fins 30 are the same height H1. These fins 30 are positioned opposite the flat surface portion 14 forming the flow path when the recess 11 is covered by the base plate 20A. Figure 6 Region A1 within the base plate 20A shown.

[0070] On the other hand, in order to cover the aforementioned recess 11, the base plate 20A, such as Figure 2 As shown, it is formed into a rectangle larger than the rectangle that forms the top view shape of the recess 11. Specifically, the length of the short side of the base plate 20A is the same as the rectangle that forms the top view shape of the shell 10A, while the length of the long side of the base plate 20A is slightly shorter than the rectangle that forms the top view shape of the shell 10A. Furthermore, as... Figure 1 As shown, the base plate 20A overlaps with the housing 10A from the +Z side. Furthermore, the base plate 20A engages with the +Z surface of the housing 10A. For example, the base plate 20A is welded to the housing 10A, or mechanically engaged with the housing 10A by bolts, screws, etc. Thus, the base plate 20A covers the recess 11 of the housing 10A to prevent refrigerant leakage.

[0071] In addition, such as Figure 8As shown, the thickness T1 of the base plate 20A is greater than the length of the fin 30, i.e., the height H1 of the aforementioned flow path. When the power module 2 is mounted on the base plate 20A, heat is sometimes applied to the base plate 20A, for example, by welding. The base plate 20A, by having the thickness T1 as described above, suppresses warping during manufacturing.

[0072] Furthermore, the outer periphery of the Z-face of the base plate 20A, which engages with the shell 10A, is flattened, for example, by cutting, to improve the engagement. As a result, a step 21 is formed between the region A1 where the fins 30 are arranged and the other regions. Moreover, this step 21 surrounds the region A1 where the fins 30 are arranged. With this structure, the region A1 where the fins 30 are arranged is thicker than other regions in the base plate 20A, resulting in increased rigidity.

[0073] In addition, such as Figure 3 and Figure 5 As shown, the base plate 20A faces the flat surface portion 14 of the housing 10A, forming the aforementioned flow path between them. Furthermore, the base plate 20A has the aforementioned plurality of fins 30 disposed within this flow path, allowing heat exchange between the refrigerant and the fins 30 as the refrigerant flows through it. As a result, the base plate 20A releases the heat transferred from the power module 2 from the fins 30 to the refrigerant, thus cooling the power module 2.

[0074] In order to efficiently transfer the heat of power module 2, such as Figure 2 As shown, the aforementioned plurality of fins 30 are arranged in a region A1 that overlaps in the Z direction with the region A2 on the +Z plane of the base plate 20A where a plurality of power modules 2 are disposed. Furthermore, this region A1 faces the flat surface portion 14 of the housing 10A. This improves the cooling efficiency of the cooler 1A for the power modules 2. Moreover, this arrangement of the plurality of fins 30 is provided on the base plate 20A.

[0075] However, the base plate 20A not only faces the flat surface portion 14 so that multiple fins 30 are located on the flat surface portion 14, but also covers the slots 12 and 13. As a result, in conventional coolers with such a base plate 20A, even if the cooling efficiency is high, the device itself is sometimes large relative to the power module 2.

[0076] Therefore, in the cooler 1A, in order to improve cooling efficiency and to make the device itself smaller relative to the power module 2, the fins 30 are arranged in a specific position.

[0077] Next, refer to Figures 9-11 The arrangement of fins 30 is explained in detail.

[0078] Figure 9 This is a bottom view of base plate 20A. Figure 10 yes Figure 9 A magnified view of region X shown. Figure 11 This is a top view showing the positional relationship between the flat surface portion 14, grooves 12, 13 and fins 30 provided on the housing 10A of the cooler 1A.

[0079] In addition, Figure 9 and Figure 10 For ease of understanding, a diagram is shown with the lower surface of the base plate 20A, i.e., the -Z plane, facing upwards. Additionally, in... Figure 11 In order to make the positional relationship easier to understand, the size of the fins 30 is emphasized, and the number of fins 30 is significantly reduced. In addition, the shape of the base plate 20A in the short side direction is also shown.

[0080] like Figure 9 and Figure 10 As shown, multiple fins 30 are arranged in a staggered configuration. That is, multiple columns of fins 30 are formed with a certain spacing, and in two adjacent columns of fins 30, one column is staggered relative to the other by half a spacing. The result is, as... Figure 10 As shown, the multiple fins 30 are configured such that, around one fin 30, other fins 30 exist at the vertices of a regular hexagon H centered on that fin 30. This increases the density of the fins 30 and improves the cooling efficiency based on the fins 30.

[0081] Furthermore, in the arrangement of the fins 30, two opposite sides S1 and S2 of the six sides of the aforementioned regular hexagon H are oriented towards the direction of refrigerant flow in the flat surface portion 14, i.e., the Y direction, which is the extension direction of the flow path. Therefore, when the refrigerant flows in the flow path, the fins 30 prevent the refrigerant from stagnating. As a result, the refrigerant is in full contact with any of the fins 30.

[0082] Furthermore, each fin 30 is formed in the shape of a regular hexagonal prism, and among the six sides of the cross-sectional hexagon of this regular hexagonal prism, two sides S3 and S4 face a direction orthogonal to the direction of refrigerant flow, namely the X direction, which is the width direction of the flow path. Therefore, the fins 30 further prevent refrigerant from stagnating. In addition, the fins 30 suppress the thickening of the temperature boundary layer by agitating the refrigerant at the corners of the cross-sectional hexagon.

[0083] Furthermore, the corners of the regular hexagonal prism, which forms the shape of fin 30, can also be rounded. Additionally, a regular hexagonal prism only needs its lateral faces to be parallel to a certain extent relative to the prism axis.

[0084] Multiple fins 30 are arranged in this way to improve the cooling efficiency of the power module 2. On the other hand, as... Figure 11As shown, multiple fins 30 are arranged in region A1, which overlaps with region A2, where power module 2 is arranged. In cooler 1A, in order to increase the proportion of these regions A1 and A2 in the size of cooler 1A itself, and to reduce the size of cooler 1A relative to power module 2, the distance D7 from region A2 through slot 12 or 13 to the short side end face, i.e., the -Y end face or +Y end face, of base plate 20A is small.

[0085] In detail, in the cooler 1A, when the distance from the -Y end of the first fin 31, which is arranged from the upstream side (i.e., the -Y side) of the flat surface portion 14 among the plurality of fins 30, to the -Y end of the flat surface portion 14 of the housing 10A is set to D8, and the distance from the second fin 32 or 33, which is arranged from the direction of the long side end (i.e., the direction of the +X end or -X end) of the flat surface portion 14 among the plurality of fins 30, to the +X end or -X end of the flat surface portion 14 is set to D3, the distance D8 is shorter than the distance D3.

[0086] Here, the distance D3 is smaller than the gap between two adjacent fins 30. That is, the distance D3 is smaller than the distance D9 from a certain fin 30 to the fin 30 adjacent to that fin 30. Therefore, when the refrigerant flows in the flow path formed by the flat surface portion 14, the refrigerant's passage through the gap between the fins 30 is suppressed compared to the passage through the gap between the fins 30. Alternatively, the refrigerant's passage through the gap between the fins 30 and the second fin 32 arranged closest to the +X end of the flat surface portion 14 is suppressed compared to the passage through the gap between the fins 30. Thus, in the cooler 1A, reduced cooling efficiency due to impaired heat exchange between the refrigerant and the fins 30 is prevented.

[0087] In cooler 1A, by making the aforementioned distance D8 shorter than such distance D3, high cooling efficiency is maintained while simultaneously reducing the distance D7 from the region A1 where the fins 30 are arranged to the -Y end face of the base plate 20A. In other words, in cooler 1A, the distance D7 from the region A2 where the power module 2 is disposed to the -Y end face of the base plate 20A is small. Therefore, cooler 1A achieves high cooling efficiency and miniaturization of the device itself. Furthermore, by miniaturizing the device itself, the wiring distance between the power module 2 and external electronic components such as capacitors is shortened, reducing inductance. This, in turn, improves the power conversion efficiency of the power module 2.

[0088] Further, in the cooler 1A, the same arrangement of the fins 30 is also implemented on the downstream side of the flat surface portion 14. That is, when a distance from the -Y end of the third fin 34, which is arranged on the most downstream side of the flat surface portion 14 among the plurality of fins 30, that is, on the +Y side, to the -Y end portion of the flat surface portion 14 of the casing 10A is defined as D10, the distance D10 is shorter than the aforementioned distance D3. Accordingly, in the cooler 1A, similarly to the case where the aforementioned distance D8 is shorter than the distance D3, high cooling efficiency of the cooler 1A and miniaturization of the device itself are achieved. In addition, the power conversion efficiency of the power module 2 is improved.

[0089] Such a relationship between the distances D8 and D3 and a relationship between the distances D10 and D3 are realized by the structure of the cooler 1A satisfying the following relational expressions (1) and (2). From this, it is found that the structure of the cooler 1A preferably satisfies the following relational expressions (1) and (2).

[0090] When a distance from the center line L3 at the center in the refrigerant flow direction of the flat surface portion 14, that is, the center in the Y direction, to the upstream end portion of the flat surface portion 14, that is, the -Y end portion is defined as D1, and a distance from the center line L3 to the -Y end of the first fin 31 is defined as D2, the distances D1 and D2 satisfy

[0091] D1-D2<D3···Relational Expression (1).

[0092] Alternatively, when a distance from the center line L3 to the downstream end portion of the flat surface portion 14, that is, the +Y end portion is defined as D4, and a distance from the center line L3 to the +Y end of the third fin 34 is defined as D5, the distances D4 and D5 satisfy

[0093] D4-D5<D3···Relational Expression (2).

[0094] By satisfying such relational expression (1) or (2), the cooler 1A can improve cooling efficiency and miniaturize the device itself. In addition, the power conversion efficiency of the power module 2 can be improved. Furthermore, the relational expression (1) or (2) includes both the relational expressions (1) and (2).

[0095] Furthermore, the grooves 12 and 13 described in Embodiment 1 are examples of the supply groove and discharge groove described in this disclosure. Additionally, the flat surface portion 14 of the housing 10A is an example of the bottom surface portion of the flow path described in this disclosure. Furthermore, the base plate 20A is an example of the base described in this disclosure. The regular hexagonal prism shape of the fins 30 is an example of the shape of a prism that is a regular hexagon in cross-section described in this disclosure. The center line L3 is an example of the reference line described in this disclosure. The through holes 121 and 131 are examples of the refrigerant supply port and refrigerant discharge port described in this disclosure. Furthermore, the inner wall of the -X end of the groove 12 with the through hole 121 is an example of the first inner wall described in this disclosure. The -X end and +X end of the groove 12 are examples of the first end and second end described in this disclosure. Additionally, the inner wall of the +X end of the groove 13 with the through hole 121 is an example of the second inner wall described in this disclosure. The +X end of groove 13 is an example of the third end as described in this disclosure.

[0096] Furthermore, in this disclosure, the region A1 of the finned surface of the base plate 20A is also referred to as the flow path region. Additionally, in this disclosure, the region other than region A1 of the finned surface of the base plate 20A, which faces the groove 13 when the base plate 20A is joined to the housing 10A, is referred to as the first groove region. Furthermore, in this disclosure, the region other than region A1 of the finned surface of the base plate 20A, which faces the groove 12 when the base plate 20A is joined to the housing 10A, is referred to as the second groove region.

[0097] As described above, in the cooler 1A of Embodiment 1, the flat surface portion 14 of the housing 10A and the fins 30 of the base plate 20A satisfy the above-described relationships (1) and (2). Therefore, the cooling efficiency is high, and the device itself is compact. As a result, the cooler 1A can not only adequately cool the power module 2, which is the object of cooling, but also shorten the wiring of the power module 2 and improve the power conversion efficiency.

[0098] Furthermore, in cooler 1A, the distance D3 from the second fin 32 or 33, which is arranged along the long side of the flat surface portion 14 among the plurality of fins 30, to the long side end of the flat surface portion 14 is shorter than the distance D9, which indicates the size of the gap between two adjacent fins 30. Therefore, it prevents the refrigerant from flowing into the gap between the second fin 32 or 33, which is arranged along the long side of the flat surface portion 14, and the long side end of the flat surface portion 14, instead of between the fins 30 themselves. As a result, the heat exchange efficiency between the fins 30 and the refrigerant is high in cooler 1A. Consequently, the cooling efficiency of power module 2 is high.

[0099] In cooler 1A, multiple fins 30 are configured such that, around one fin 30, other fins 30 are present at the vertices of a regular hexagon H centered on that fin 30. Furthermore, two opposite sides S1 and S2 of the six sides of the regular hexagon H extend towards the shorter side of the flat surface portion 14, i.e., the direction of the flow path that serves as the direction of refrigerant flow. Therefore, in cooler 1A, when the refrigerant flows in the flow path, the refrigerant is less likely to stagnate.

[0100] Furthermore, each fin 30 is formed in the shape of a regular hexagonal prism. Therefore, in the cooler 1A, the refrigerant is easily agitated when it flows in the flow path. As a result, the thickening of the temperature boundary layer is suppressed, and the heat exchange efficiency between the refrigerant and the fins 30 is high.

[0101] Furthermore, each fin 30 protrudes from the base plate 20A and abuts against the flat surface portion 14 of the housing 10A. Therefore, each fin 30 dissipates heat not only to the refrigerant but also to the housing 10A. The housing 10A, like the base plate 20A, is formed of a metal with high thermal conductivity, thus exhibiting high heat dissipation. As a result, the cooling efficiency of the power module 2 is high in the cooler 1A.

[0102] In cooler 1A, the length L1 of the long side of the cross-sectional rectangle of slots 12 and 13, i.e., the depth of slots 12 and 13, is greater than the length L2 of the short side of the cross-sectional rectangle of slots 12 and 13, i.e., the width of slot 12. Furthermore, the depth of slots 12 and 13 is greater than the size of the gap between the flat surface portion 14 and the base plate 20A, i.e., the height H1 of the flow path. In slot 12, refrigerant is supplied from the bottom side, resulting in the refrigerant flowing from the bottom of slot 12 towards the opening of slot 12. Alternatively, in slot 13, refrigerant is discharged from the opening side, resulting in the refrigerant flowing from the opening of slot 13 towards the bottom of slot 12. Therefore, before the refrigerant flows from the bottom of slot 12 into the flow path, the refrigerant easily spreads along the entire extension direction of slot 12, and is less likely to become uneven. As a result, refrigerant is easily distributed in slot 12. Similarly, in slot 13, refrigerant easily accumulates.

[0103] Furthermore, refrigerant connectors 122 and 132 are connected to the inner walls of tanks 12 and 13 for refrigerant flow. Moreover, the inner diameter of connectors 122 and 132 is smaller than the depth of tanks 12 and 13, resulting in a smaller cross-sectional area for connectors 122 and 132 compared to the cross-sectional area of ​​tanks 12 and 13. Therefore, pressure loss is minimal in the refrigerant flow between tanks 12 and 13 and connectors 122 and 132.

[0104] (Variation example)

[0105] In Embodiment 1 described above, the thickness T1 of the base plate 20A is thicker than the height of the fins, i.e., the height H1 of the flow path, but the thickness T1 of the base plate 20A is not limited to this. For example, the thickness T1 of the base plate 20A may also be less than or equal to the height H1 of the flow path. In Embodiment 1, six power modules 2 are provided on the base plate 20A. However, if the number of these power modules 2 is smaller, it is difficult for the base plate 20A to warp even if the thickness T1 of the base plate 20A is thin. As a result, the base plate 20A will not warp even if the thickness T1 of the base plate 20A is less than or equal to the height H1 of the flow path.

[0106] (Implementation Method 2)

[0107] In Embodiment 1, the region A1 where the fins 30 are arranged overlaps with the flat surface portion 14 of the shell 10A when viewed from above. That is, the plurality of fins 30 are arranged within the flow path formed by the flat surface portion 14. However, the arrangement of the fins 30 is not limited to this. The arrangement of the fins 30 is sufficient as long as it satisfies the above-described relationships (1) and (2). For example, the plurality of fins 30 may also be arranged not only in the flow path formed by the flat surface portion 14, but also in at least one of the internal spaces of the slots 12 and 13.

[0108] In the cooler 1B of embodiment 2, a plurality of fins 30 are arranged not only in the flow path formed by the flat surface portion 14, but also in the internal spaces of both slots 12 and 13.

[0109] The following is for reference Figure 12 and Figure 13 The cooler 1B of Embodiment 2 will be described. In Embodiment 2, the description will focus on the structure that differs from that of Embodiment 1.

[0110] Figure 12 This is a cross-sectional view of the cooler 1B according to embodiment 2. Figure 13 This is a top view showing the positional relationship between the flat surface portion 14, grooves 12, 13, and fins 30 provided on the housing 10B of the cooler 1B. Furthermore, in Figure 12 In, it is shown that in relation to Figure 1 Cooler 1B is cut at the same location as the III-III cut line shown.

[0111] like Figure 12 As shown, the extension length of the flow path provided in the housing 10B of the cooler 1B, i.e., the length L4 of the flat surface portion 14, is smaller than that in Embodiment 1. Figure 3 The length L5 of the flat surface portion 14 shown. The result is as follows: Figure 13As shown, the region A1 where the fins 30 arranged on the lower surface of the base plate 20B are arranged does not overlap only with the flat surface portion 14 when viewed from above. Region A1 overlaps not only with the flat surface portion 14, but also with the grooves 12 and 13 adjacent to the flat surface portion 14 when viewed from above. Therefore, the multiple fins 30 protrude not only into the flow path formed by the flat surface portion 14, but also into the internal space of the grooves 12 and 13.

[0112] In the cooler 1B with such fins 30, the above-described relationships (1) and (2) are satisfied in the same way as in embodiment 1. As a result, the distance D7 from the region A1 where the fins 30 are arranged to the -Y end face of the base plate 20B is small. That is, the distance D7 from the region A2 where the power module 2 is arranged to the -Y end face of the base plate 20B is small. Thus, miniaturization of the device itself is achieved in the cooler 1B. In addition, the cooler 1B shortens the wiring distance when the power module 2 is connected to external electronic components, and reduces inductance. As a result, the power conversion efficiency of the power module 2 is improved in the cooler 1B.

[0113] Furthermore, in cooler 1B, similarly to embodiment 1, the distance D3 from the second fin 32 or 33 arranged along the long side of the flat surface portion 14 among the plurality of fins 30 to the long side end of the flat surface portion 14 is smaller than the distance D9 from a certain fin 30 to the fin 30 adjacent to that fin 30, i.e., the size of the gap between two adjacent fins 30. As a result, in cooler 1B, when the refrigerant flows, it is prevented that the refrigerant flows into the gap between the second fin 32 or 33 arranged along the long side of the flat surface portion 14 and the long side end of the flat surface portion 14 instead of between the fins 30 themselves. As a result, in cooler 1B, the heat exchange efficiency between the fins 30 and the refrigerant is high, and the cooling efficiency of the power module 2 is high.

[0114] Furthermore, the base plate 20B is an example of the base described in this disclosure.

[0115] As described above, in the cooler 1B of Embodiment 2, similarly to Embodiment 1, the flat surface portion 14 of the housing 10B and the fins 30 of the base plate 20B satisfy the above-described relationships (1) and (2), thus the device itself is compact. As a result, the wiring of the power module 2 can be shortened, and the power conversion efficiency can be improved.

[0116] In detail, in the cooler 1B, multiple fins 30 protrude not only into the flow path formed by the flat surface portion 14, but also into the internal spaces of the slots 12 and 13. Furthermore, these fins 30 are arranged in region A1, which overlaps with the power module 2, which is the object to be cooled. Therefore, the power module 2 can be positioned close to the end of the base plate 20B. Consequently, in the cooler 1B, the wiring distance for connecting the power module 2 to external electronic components can be shortened, improving power conversion efficiency.

[0117] Furthermore, in cooler 1B, similarly to embodiment 1, the distance D3 from the second fin 32 or 33 arranged along the long side of the flat surface portion 14 to the long side end of the flat surface portion 14 is shorter than the distance D9, which indicates the size of the gap between two adjacent fins 30. Therefore, it prevents the refrigerant from flowing into the gap between the second fin 32 or 33 arranged along the long side of the flat surface portion 14 and the long side end of the flat surface portion 14, rather than between the fins 30 themselves. As a result, the heat exchange efficiency between the fins 30 and the refrigerant is high in cooler 1B. Consequently, the cooling efficiency of power module 2 is high.

[0118] (Variation example)

[0119] In embodiment 2, the plurality of fins 30 are arranged not only in the flow path formed by the flat surface portion 14, but also in the internal spaces of both grooves 12 and 13. However, in addition to being arranged in the flow path formed by the flat surface portion 14, the plurality of fins 30 may also be arranged in the internal space of at least one of grooves 12 and 13.

[0120] Figure 14 This is a cross-sectional view of a modified example of the cooler 1B according to Embodiment 2.

[0121] like Figure 14 As shown, the multiple fins 30 can be arranged not only in the flow path formed by the flat surface portion 14, but also in the internal space of the groove 13. This is because, in this manner, when the refrigerant flows in the flow path formed by the flat surface portion 14, the refrigerant that has exchanged heat with the fins 30 flows downstream, resulting in less reduction in the cooling performance of the cooler 1B. Furthermore, even in this manner, the refrigerant flowing in from the flow path formed by the flat surface portion 14 flows in the groove 13 due to inertia, thus having little impact on the cooling performance of the cooler 1B. Therefore, when the multiple fins 30 are arranged not only in the flow path formed by the flat surface portion 14, but also in the internal space of at least one of the grooves 12 and 13, it is preferable that they are arranged in the internal space of the groove 13.

[0122] (Implementation Method 3)

[0123] In embodiments 1 and 2, through holes 121 and 131 extending from the inner wall of the grooves 12 and 13 in the extending direction are formed therein. Furthermore, pipe fittings 122 and 132 are embedded in these through holes 121 and 131. Thus, refrigerant flows from the extending direction (X direction) of the grooves 12 and 13 into the grooves 12 and 13. However, the direction of refrigerant flow into the grooves 12 and 13 is not limited to this. The groove 12 can simply be a supply groove for supplying refrigerant to the flow path. In this case, since the flow path is adjacent to the supply groove, it is preferable that the refrigerant flows from the bottom of the groove toward the opening in the supply groove. Similarly, the groove 13 can simply be a discharge groove for discharging refrigerant from the flow path. In this case, since the flow path is adjacent to the discharge groove, it is preferable that the refrigerant flows from the opening of the groove toward the bottom in the discharge groove.

[0124] In the cooler 1C of embodiment 3, a through hole for supplying refrigerant is provided on the side wall of the tank 12. Additionally, a through hole for discharging refrigerant is provided on the side wall of the tank 13.

[0125] The following is for reference Figure 15 and Figure 16 The cooler 1C of Embodiment 3 will be described. In Embodiment 3, the description will focus on the structure that differs from that of Embodiments 1 and 2.

[0126] Figure 15 This is a perspective view of the cooler 1C according to embodiment 3. Figure 16 yes Figure 15 The cross-sectional view shown is along the XVI-XVI cut line.

[0127] like Figure 15 and Figure 16 As shown, pipe fittings 123 and 133 for supplying refrigerant are connected to the end face portion of the housing 10C in the short side direction.

[0128] like Figure 16 As shown, the pipe connector 123 is connected to the groove 12. Specifically, the groove 12 is formed in a rectangular shape in YZ cross-section. Furthermore, the groove 12 extends in the X direction while maintaining its cross-sectional shape. As a result, the groove 12 has two flat sidewalls facing each other in the Y direction. Moreover, a through hole 124 is formed on the sidewall located near the outer side of the housing 10C. This through hole 124 is formed at a position contacting the -Z surface of the groove 12, i.e., the bottom. The pipe connector 123 is embedded in the through hole 124. As a result, in the presence of refrigerant flow, the refrigerant is supplied to the bottom of the groove 12 through the pipe connector 123. Thus, in the groove 12, the refrigerant flows in a direction from the bottom toward the opening.

[0129] As described in Embodiment 1, the groove 12, when viewed in a YZ cross-section, has a rectangular shape with its long side facing the Z direction and its short side facing the Y direction. Furthermore, the length L1 of the long side of the YZ cross-section rectangle is greater than the length L2 of the short side. That is, the depth of the groove 12 is greater than its width. As a result, when the refrigerant flows in the groove 12 in the direction from the bottom towards the opening, the resistance to the refrigerant increases on the opening side of the groove 12. Consequently, the refrigerant easily expands in the extending direction of the groove 12, i.e., the X direction, and is less likely to become uneven. As a result, the refrigerant is easily distributed in the groove 12.

[0130] On the other hand, the pipe connector 133 is connected to the groove 13. Specifically, the groove 13 is formed in a shape symmetrical to the groove 12. As a result, the groove 13 also has two flat sidewalls facing each other in the Y direction. A through hole 134 is formed on the sidewall located near the outer side of the housing 10C. This through hole 134, like the through hole 124, is formed at a position contacting the bottom of the groove 13. Furthermore, the pipe connector 133 is embedded in the through hole 134. As a result, the pipe connector 133 discharges the refrigerant from the bottom of the groove 13 when the refrigerant flows through the cooler 1C.

[0131] Like tank 12, tank 13 is deeper than it is wide. As a result, when the refrigerant flows towards the bottom of tank 13, the resistance to the refrigerant is greater on the side closer to the bottom than the opening. Consequently, the refrigerant tends to expand more easily in the X-direction of tank 13, preventing it from becoming uneven. Therefore, in tank 12, the refrigerant tends to accumulate.

[0132] Furthermore, the base plate 20C is an example of the base described in this disclosure.

[0133] As described above, in the cooler 1C of Embodiment 3, the pipe joint 123 is connected to the side wall of the tank 12, and refrigerant is supplied to the bottom side of the tank 12. In the cooler 1C, similarly to the coolers 1A and 1B, the depth of the tank 12 is greater than the width of the tank 12, so when the refrigerant flows from the bottom of the tank 12 to the opening side of the tank 12, it is easy to distribute the refrigerant in the extending direction of the tank 12.

[0134] Furthermore, in the cooler 1C, the pipe joint 133 is connected to the side wall of the tank 13, and refrigerant is discharged from the bottom side of the tank 13. The depth of the tank 13 is also greater than its width. Therefore, when the refrigerant flows from the opening of the tank 13 towards the bottom side, it easily accumulates in the extending direction of the tank 13.

[0135] (Implementation Method 4)

[0136] In embodiments 1 to 3, the housings 10A to 10C are formed of a metal with high thermal conductivity from the flat surface portion 14 to the bottom. This improves the heat dissipation of the housings 10A to 10C. However, the housings 10A to 10C are not limited to this. The housings 10A to 10C only need to have, internally, a flat surface portion 14 for refrigerant flow, i.e., the bottom surface portion of the flow path, a channel 12 adjacent to the upstream end of the bottom surface portion for supplying refrigerant to the flow path, and a channel 13 adjacent to the downstream end of the bottom surface portion for discharging refrigerant from the flow path. Therefore, the lower structure of the flat surface portion 14 of the housings 10A to 10C is arbitrary as long as this condition is met.

[0137] In embodiment 4, the flat surface portion 14 is formed of a metal plate.

[0138] The following is for reference Figure 17 The cooler 1D of Embodiment 4 will be described. In Embodiment 4, the description will focus on the structure that differs from that of Embodiments 1 to 3.

[0139] Figure 17 This is a cross-sectional view of the cooler 1D according to embodiment 4. Furthermore, in Figure 17 In, it is shown that in relation to Figure 1 Cooler 1D is cut at the same location as the III-III cut line shown.

[0140] like Figure 17 As shown, in the cooler 1D, the housing 10D has a box shape with an open top surface. Moreover, the housing 10D has a partition wall 16 that divides the internal space 15 of the box in two.

[0141] In detail, the housing 10D has an elongated cuboid-shaped internal space 15 with its long side facing the left-right direction, i.e., the X direction. A partition wall 16 is disposed in this elongated cuboid-shaped internal space 15, dividing the internal space 15 into two. More specifically, the partition wall 16 has a flat plate shape with its plate surface facing the Y direction. In addition, the partition wall 16 is disposed at the center of the internal space 15 of the housing 10D in the Y direction. As a result, the partition wall 16 divides the internal space 15 of the housing 10D into two.

[0142] One of the spaces in the internal space 15, which is divided into two by the partition wall 16 of the shell 10D, namely the first space 151 on the -Y side, is connected to... Figure 17 Pipe connector 122 (not shown). As described in Embodiment 1, pipe connector 122 is connected to a piping extending from an external device (not shown) from which refrigerant is supplied. Thus, refrigerant is supplied to the first space 151.

[0143] In contrast, in the other space of the divided internal space 15, namely the second space 152 on the +Y side, there is... Figure 17 Pipe fitting 132 (not shown). As described in Embodiment 1, pipe fitting 132 is connected to a piping extending to an external device (not shown), allowing refrigerant to be discharged to that external device. As a result, refrigerant can be discharged from the second space 152.

[0144] On the other hand, the cooler 1D has a metal plate 17 that covers most of the interior space 15 of the housing 10D and abuts against the fins 30 of the base plate 20D to form a flow path.

[0145] In detail, the metal plate 17 is formed of a metal material with high thermal conductivity and has a rectangular plate shape. This rectangle has a width W2 that is smaller than the width W1 of the internal space 15 of the housing 10D described above. Although not shown, the length of the metal plate 17 is the same as the length of the long side direction, i.e., the X direction, of the internal space 15 of the housing 10D. Moreover, the metal plate 17 is embedded into the internal space 15 of the housing 10D. The height H2 of the partition wall 16 described above is smaller than the height H3 of the internal space 15 than the sum of the height H1 of the flow path described in Embodiment 1 and the thickness T2 of the metal plate 17. As a result, when the metal plate 17 is embedded into the internal space 15 and abuts against the +Z end of the partition wall 16, it is located at a position offset from the flow path by a height H1 from the +Z end of the housing 10D towards the -Z side. The metal plate 17 is fixed to the partition wall 16 while abutting against the +Z end of the partition wall 16. For example, the metal plate 17 is brazed to the partition wall 16, or fixed to the partition wall 16 via an elastomer such as rubber or a spring.

[0146] The base plate 20D abuts against the +Z end face of the housing 10D, covering the internal space 15 of the housing 10D. As a result, the metal plate 17 is positioned at a height H1 above the flow path, opposite the base plate 20D, and abuts against the fins 30 of the base plate 20D. Consequently, the metal plate 17 and the base plate 20D form a flow path. With this structure, the metal plate 17 forms the flat surface portion 14 of the flow path.

[0147] As described above, the width W2 of the metal plate 17 is smaller than the width W1 of the internal space 15. As a result, a gap is formed between the metal plate 17 and the inner wall of the internal space 15 on the -Y side of the housing 10D. Thus, a groove 12 is formed on the -Y side of the metal plate 17. The groove 12 is connected to the first space 151 and is deeper than the thickness T2 of the metal plate 17. Furthermore, refrigerant is supplied to the first space 151 from the pipe joint 122, resulting in the groove 12 being filled with refrigerant, which is then supplied to the flow path of the metal plate 17.

[0148] Furthermore, the metal plate 17 forms gaps not only between itself and the inner wall of the internal space 15 on the -Y side of the housing 10D, but also between itself and the inner wall on the +Y side. Thus, the metal plate 17 forms a groove 13 adjacent to the +Y side of the metal plate 17. The groove 13 is connected to the second space 152 and is therefore deeper than the thickness T2 of the metal plate 17. Moreover, the second space 152 is capable of discharging refrigerant from the pipe joint 132, resulting in the refrigerant being discharged from the pipe joint 132 when it flows into the metal plate 17 through the flow path.

[0149] In the housing 10D, the metal plate 17 has a structure such that, similar to embodiments 1-3, the width of the +Z side of the grooves 12 and 13, i.e., the width of the opening side, is narrower than the width of the bottom side of the grooves 12 and 13, i.e., the width of the first space 151 and the second space 152. Therefore, when the refrigerant flows from the first space 151 to the opening side of the groove 12, it is easy to distribute the refrigerant in the extension direction of the groove 12, i.e., the X direction of the groove 12. In addition, when the refrigerant flows from the opening of the groove 13 to the second space 152, it is easy to collect the refrigerant in the extension direction of the groove 13, i.e., the X direction.

[0150] Furthermore, the base plate 20D is an example of a base as described in this disclosure. Additionally, the metal plate 17 is an example of a plate-like body as described in this disclosure.

[0151] As described above, the housing 10D of Embodiment 4 has a metal plate 17 inside, which faces the base plate 20D and forms a flat surface portion 14 for forming a flow path. Moreover, grooves 12 and 13 are provided at one end and the other end of the metal plate 17, and are formed to be deeper than the thickness T2 of the metal plate 17. In the cooler 1D, the flat surface portion 14 can be formed using the metal plate 17, thus making manufacturing easy.

[0152] Furthermore, the housing 10D has an internal space 15 adjacent to the metal plate 17 on the opposite side of the metal plate 17 and the base plate 20D. The internal space 15 is divided into a first space 151 and a second space 152 by a partition wall 16 that abuts against the metal plate 17. Moreover, the metal plate 17 forms grooves 12 and 13 that connect to the first space 151 and the second space 152 by providing a gap between itself and the internal space 15. In the cooler 1D, the grooves 12 and 13 can be formed simply by using the partition wall 16 to divide the internal space 15 and by using the metal plate 17 to cover the internal space 15 with a gap, thus making manufacturing easy.

[0153] In cooler 1D, the width of the opening side of slots 12 and 13 is narrower than the width of the bottom side of slots 12 and 13. Therefore, it is easier to distribute refrigerant in slot 12. In addition, it is easier to collect refrigerant in slot 13.

[0154] Furthermore, in Embodiment 4, the metal plate 17 can be replaced with other plate-like materials. That is, the metal plate 17 can also be a plate made of a material other than the metal material described above, which is an example of a plate-like material in this disclosure, such as a resin material.

[0155] The coolers 1A to 1D and the semiconductor device according to the embodiments of the present disclosure have been described above, but the coolers 1A to 1D and the semiconductor device are not limited thereto.

[0156] For example, in embodiments 1 and 2, grooves 12 and 13 are, in cross-section, a combination of rectangles and circles. Furthermore, in embodiments 3 and 4, grooves 12 and 13 are, in cross-section, rectangles with their long sides pointing towards the depth direction or rectangles with their long sides pointing towards the width direction. However, the shapes of grooves 12 and 13 are not limited to these. As described above, groove 12 can simply be a supply groove for supplying refrigerant to the flow path. In this case, since the flow path is adjacent to the supply groove, it is preferable that the refrigerant flows in the supply groove from the bottom of the groove towards the opening. Additionally, as described above, groove 13 can simply be a discharge groove for discharging refrigerant from the flow path. In this case, since the flow path is adjacent to the discharge groove, it is preferable that the refrigerant flows in the discharge groove from the opening towards the bottom.

[0157] Figures 18-20 These are cross-sectional views of the first to third variations of the grooves 12 and 13 formed on the housing 10A of the cooler 1A.

[0158] like Figure 18 As shown, channels 12 and 13 can also be rectangles with their longer sides pointing towards the depth direction in cross-section, and connected to pipe fittings 122 and 132 from the direction perpendicular to their cross-section, i.e., the X direction perpendicular to the YZ cross-section. This is because, in this configuration, the resistance to refrigerant is greater when the refrigerant flows towards the depth direction, making it easier to distribute the refrigerant towards the extension direction of channels 12 and 13. In this case, the width in the Y direction and the depth in the Z direction of the YZ cross-sectional rectangle of channels 12 and 13 need to be greater than the inner diameter of pipe fittings 122 and 132.

[0159] In addition, such as Figure 19 and Figure 20 As shown, slots 12 and 13 can also be shaped like a large rectangle connected to a smaller rectangle in cross-section. More specifically, slots 12 and 13 can also be shaped like a second rectangle with a smaller width in the Y direction connected to the +Z side of a first rectangle with a larger width in the Y direction in a YZ cross-section. In this case, as... Figure 19 As shown, pipe fittings 122 and 132, whose inner diameters are smaller than the width in the Y direction and the height in the Z direction of any one of the first and second rectangles, can be used. Additionally, as... Figure 20As shown, pipe fittings 122 and 132 with openings that are sectionally rectangular can also be connected.

[0160] Furthermore, in embodiments 1 to 4, channels 12 and 13 extend with the same cross-sectional shape. However, the shapes of channels 12 and 13 are not limited to this. As described above, channel 12 can be any supply channel for supplying refrigerant to the flow path. Similarly, channel 13 can be any discharge channel for discharging refrigerant from the flow path. Therefore, the cross-sectional shapes of channels 12 and 13 can also vary in the extending direction.

[0161] Figure 21 This is a cross-sectional view of a fourth modified example of the groove 12 formed on the housing 10A of the cooler 1A.

[0162] like Figure 21 As shown, the groove 12 can also have a first groove connected to the +X side of the through hole 121, which is a circular cross-section hole connected to the pipe connector 122. This first groove has a shape that is a rectangle with its long side facing the Z direction in cross-section, and a semicircle protruding from the side of the rectangle extending along its long side. Furthermore, a second groove, which is only a rectangle with its long side facing the Z direction in cross-section, can also be connected to the +X side of the first groove. If this is the case, manufacturing is easy because there is a first groove with a combined shape of the circular cross-section hole 121 and the rectangular cross-section second groove between the circular cross-section hole 121 and the rectangular cross-section second groove.

[0163] In embodiments 1 to 4, all fins 30 are regular hexagonal prisms, resulting in all fins 30 having the same shape. However, the fins 30 are not limited to this. Multiple fins 30 can be arranged on the side of the base plates 20A to 20D opposite to the surface where the cooling object is located. Therefore, the fins 30 do not have to be all the same shape, and multiple fins 30 with different shapes can be mixed.

[0164] Figure 22 This is a top view showing the positional relationship between the end of the flat surface portion 14 of the housing 10A of the cooler 1A and a modified example of the fins 30.

[0165] like Figure 22As shown, multiple fins 30 of a regular hexagonal prism and fins 40 of a shape cut along the prism axis can also be mixed and arranged in the flat surface portion 14. As explained in Embodiment 1, the multiple fins 30 are arranged in a staggered configuration. As a result, the groups of fins 30 forming columns in the X direction are arranged in the Y direction. Moreover, the columns of fins 30 arranged at a certain interval in the X direction are offset by half a spacing from other columns adjacent to them in the Y direction in the X direction. As a result, regions A3 without fins 30 are sometimes generated at the end of the flat surface portion 14 every other column. Moreover, these regions A3 are sometimes not the size of the fins 30 arranged in a complete shape. Therefore, as Figure 22 As shown, each region A3 is provided with incompletely shaped fins 40. Each fin 40 is shaped like a prism with a trapezoidal cross-section, resulting from cutting a regular hexagonal prism along its axis. This ensures that the distance from the end of the flat surface portion 14 to the nearest fin 30 is the same as the distance from the end of the flat surface portion 14 to the fin 40, preventing refrigerant from passing through each region A3.

[0166] In this way, multiple fins of different shapes, such as 30 and 40, can also be mixed.

[0167] Furthermore, in embodiments 1 to 4, the fin 30 is a regular hexagonal prism, but the fin 30 can also be a prism with a regular hexagonal cross section. In this case, the prism cross section can be a regular hexagonal, so the fin 30 can also become thinner as it faces the front end.

[0168] Furthermore, in embodiments 1 to 4, the object cooled by coolers 1A to 1D is the power module 2, but coolers 1A to 1D are not limited to this. The object cooled can be any object that exchanges heat with the refrigerant and is cooled. Therefore, the object cooled by coolers 1A to 1D can also be a semiconductor device other than the power module 2, for example, a light-emitting diode.

[0169] In embodiments 1 to 4, the structure of coolers 1A to 1D with the long side of the rectangular base plates 20A to 20D facing left-right and the short side facing front-back was described. However, this orientation is for the convenience of explaining the structure of coolers 1A to 1D. As long as the relative positional relationship between the structures of coolers 1A to 1D is maintained, the orientation of coolers 1A to 1D is arbitrary.

[0170] Various embodiments and modifications can be made to this disclosure without departing from its broad spirit and scope. Furthermore, the above embodiments are illustrative of this disclosure and do not limit its scope. That is, the scope of this disclosure is not shown by the embodiments, but by the claims. Moreover, various modifications implemented within the scope of the claims and their equivalents are considered to be within the scope of this disclosure.

[0171] Label Explanation

[0172] 1A-1D: Cooler; 2: Power module; 10A-10D: Housing; 11: Recess; 12, 13: Groove; 14: Flat surface portion; 15: Internal space; 16: Partition wall; 17: Metal plate; 20A-20D: Base plate; 21: Step; 30: Fin; 31: First fin; 32, 33: Second fin; 34: Third fin; 40: Fin; 121: Through hole; 122: Pipe connector; 123: Pipe connector Head; 124: Through hole; 131: Through hole; 132: Pipe connector; 133: Pipe connector; 134: Through hole; 151: First space; 152: Second space; A1~A3: Region; L1, L2: Length; L3: Centerline; D1~D5: Distance; D6: Diameter; D7~D10: Distance; H: Regular hexagon; H1~H3: Height; S1~S4: Side; T1, T2: Thickness; W1, W2: Width.

Claims

1. A cooler comprising a housing and a base, The housing has inside a bottom portion of a flow path, which has a rectangular shape with two opposing sides facing upstream and downstream for refrigerant flow; a supply groove, which is disposed at an upstream end portion of the bottom surface portion, is recessed relative to the upstream end portion, and supplies the refrigerant flowing inside to the flow path; and a discharge groove, which is disposed at a downstream end portion of the bottom surface portion, is recessed relative to the downstream end portion, and allows the refrigerant flowing in from the flow path to flow inside and be discharged, a heating element is disposed on one surface side of the base, the other surface faces the bottom surface portion of the flow path to cover the bottom surface portion, the supply groove and the discharge groove, and a plurality of fins are arranged on the other surface side, the plurality of fins are disposed in a flow path region that is at least the flow path region of the other surface of the base that faces the bottom surface portion, and is a flow path region that overlaps with the region where the heating element is disposed on the one surface of the base when viewed from a direction perpendicular to the other surface, the plurality of fins are arranged in the extending direction of the flow path from the upstream end portion to the downstream end portion of the bottom surface portion, and when viewed from the direction perpendicular to the other surface, the plurality of fins are arranged in the width direction of the flow path orthogonal to the extending direction of the flow path, where, when D1 is defined as the distance from a reference line set on the bottom surface portion and extending in the width direction to the upstream end portion of the bottom surface portion, D2 is defined as the distance from the reference line to the upstream end of the first fin arranged at the most upstream side among the plurality of fins, and D3 is defined as the distance from the end portion in the width direction of the flow path to the second fin closest to the end portion among the plurality of fins, the relational expression D1-D2<D3 is satisfied, or, when D4 is defined as the distance from the reference line to the downstream end portion of the bottom surface portion, and D5 is defined as the distance from the reference line to the downstream end of the third fin arranged at the most downstream side among the plurality of fins, the relational expression D4-D5<D3 is satisfied.

2. The cooler according to claim 1, wherein the distance from the second fin to the end portion of the bottom surface portion that is closest to the second fin in the width direction of the flow path is smaller than the size of the gap between two adjacent fins among the plurality of fins.

3. The cooler according to claim 1 or 2, wherein the other surface of the base faces the bottom surface portion of the housing, the plurality of fins are arranged in the flow path region on the other surface of the base and a first groove region on the other surface that faces the discharge groove.

4. The cooler according to claim 1 or 2, wherein the other surface of the base faces the bottom surface portion of the housing, the plurality of fins are arranged in the flow path region on the other surface of the base and a second groove region on the other surface that faces the discharge groove.

5. The cooler according to claim 1 or 2, wherein The plurality of fins are arranged in the flow path region of the other side of the base, the first groove region of the other side opposite the discharge groove, and the second groove region of the other side opposite the supply groove.

6. The cooler according to any one of claims 1 to 5, wherein, The plurality of fins are configured such that, around one fin, other fins exist at the vertices of a regular hexagon centered on that fin. The regular hexagon is a shape in which two opposite sides of the six sides face the direction of extension of the flow path.

7. The cooler according to claim 6, wherein, The plurality of fins are each shaped like a column with a regular hexagonal cross-section. Two of the six sides of the regular hexagon face the width direction of the flow path.

8. The cooler according to any one of claims 1 to 7, wherein, The depth of the supply channel is greater than the width of the supply channel, and greater than the height from the bottom portion of the flow path to the other side of the base. In the supply tank, the refrigerant flows from the bottom of the supply tank toward the opening of the supply tank covered by the base.

9. The cooler according to claim 8, wherein, The supply tank has a first inner wall with a refrigerant supply port located closer to the bottom side than the opening of the supply tank, and smaller than the width and depth of the supply tank.

10. The cooler according to claim 9, wherein, The supply channel extends along the width direction of the flow path. The first inner wall is formed at a first end located in the extending direction of the supply channel.

11. The cooler according to claim 9, wherein, The supply channel extends along the width direction of the flow path. The width direction of the supply channel is oriented towards the extension direction of the flow path. The first inner wall is the sidewall of the supply groove facing the extension direction of the flow path.

12. The cooler according to claim 9, wherein, The supply channel has a first end located in the extending direction of the supply channel, which, in cross-section, is formed by the overlap of a rectangle and a circle. The long side of the rectangle faces the depth direction of the supply channel, and the circle has a diameter smaller than the length of the long side of the rectangle and larger than the length of the short side of the rectangle. Furthermore, the supply channel has a second end located in the extending direction of the supply channel, opposite to the first end, which, in cross-section, has a rectangular shape identical to the cross-sectional shape of the first end. The circle is tangent to a first side of the rectangle, which extends along its long side and is located on the opposite side of the bottom portion of the flow path, and is also tangent to a second side located on the bottom side of the rectangle. The first inner wall is formed at the first end of the supply channel. The refrigerant supply port has a diameter smaller than the diameter of the circle.

13. The cooler according to any one of claims 1 to 12, wherein, The housing has an internal plate-like body that faces the base and forms the bottom portion of the flow path. The supply groove is located at one end of the plate-shaped body and is formed to be deeper than the thickness of the plate-shaped body. The discharge groove is located at the opposite end of the plate-shaped body on the side opposite to one end, and is formed to be deeper than the thickness of the plate-shaped body.

14. The cooler according to claim 13, wherein, The housing has an internal space adjacent to the plate-like body on the side opposite to the surface of the plate-like body and the base. The interior space is divided into a first space and a second space by a partition wall that abuts against the plate-like body. The supply tank is connected to the first space, and refrigerant is supplied to the first space from an external device through the supply tank. The discharge trough is connected to the second space, and an outwardly extending pipe is connected to the second space, thereby discharging refrigerant from the discharge trough to the outside.

15. The cooler according to any one of claims 1 to 14, wherein, The depth of the discharge channel is greater than the width of the discharge channel, and greater than the height of the flow path from the bottom portion of the flow path to the other side of the base. In the discharge trough, the refrigerant flows from the opening of the discharge trough, which is covered by the base, toward the bottom of the discharge trough.

16. The cooler according to claim 15, wherein, The discharge trough has a second inner wall forming a refrigerant discharge port, which is located closer to the bottom side than the opening of the discharge trough and is smaller than the width and depth of the discharge trough.

17. The cooler according to claim 16, wherein, The discharge channel extends along the width direction of the flow path. The second inner wall is formed at the third end of the discharge groove in the extending direction.

18. The cooler according to claim 16, wherein, The discharge channel extends along the width direction of the flow path. The width direction of the discharge groove is oriented towards the extension direction of the flow path. The second inner wall is the sidewall of the discharge groove facing the extension direction of the flow path.

19. The cooler according to any one of claims 1 to 18, wherein, The plurality of fins abut against the bottom surface portion of the flow path of the housing.

20. The cooler according to any one of claims 1 to 19, wherein, The base has the shape of a plate that is thicker than the height of the flow path from the bottom portion of the flow path to the other side of the base.

21. The cooler according to any one of claims 1 to 20, wherein, In the supply tank, the refrigerant flows from the bottom of the supply tank toward the opening of the supply tank covered by the base. The width of the supply channel is less than the depth of the supply channel. The height of the flow path from the bottom portion of the flow path to the other side of the base is less than the width of the supply channel. The fins have a column shape with a diameter smaller than the height of the flow path.

22. A semiconductor device comprising: The cooler according to any one of claims 1 to 21; and The heating element. The heating element is a semiconductor device.

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