Radiator and semiconductor module

Abstract

The heat sink (3) has a refrigerant flow path (4) formed inside thereof for refrigerant to flow, and the heat sink (3) comprises: a heat conduction plate (31) having a first surface (31a) and a second surface (31b) on which a semiconductor element (2) is arranged; a relay flow path forming plate (33) having a third surface (33a) and a fourth surface (33b); a first partition wall (12) arranged to contact the second surface (31b) and the third surface (33a); and a first fin (13) arranged to contact the second surface (31b). The refrigerant flow path (4) includes a first flow path (5). A plurality of first divided areas (51) separated by the first partition wall (12) are formed in the first flow path (5). In the first divided area (51), a plurality of first fins (13) are arranged to be spaced apart from each other. The position when at least a portion of the first partition wall (12) is projected onto the first surface (31a) or the position when at least a portion of the first fin (13) is projected onto the first surface (31a) overlaps with the center of the semiconductor element (2).

Description

Technical Field

[0001] The present invention relates to a heat sink and a semiconductor module for cooling a cooling object such as a semiconductor element. Background Art

[0002] Currently, heat sinks for cooling semiconductor elements and the like are known. For example, Patent Document 1 discloses a heat sink having: a rectangular base plate on which a semiconductor element is mounted on a surface; a plurality of fins mounted on the back side of the base plate in a manner arranged parallel to each other; and a refrigerant nozzle that sprays a refrigerant toward the back side of the base plate.

[0003] The heat sink disclosed in Patent Document 1 is provided with 12 fins, which are arranged in 6 rows in the width direction of the base plate and 2 rows in the length direction of the base plate. A refrigerant nozzle is embedded between the fins arranged in the length direction of the base plate. When viewed from above, the refrigerant nozzle and the center of the semiconductor element are arranged at a position where they overlap each other.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-150117 Summary of the invention

[0005] However, the heat sink disclosed in Patent Document 1 has no fins at a position overlapping with the center of the semiconductor element, so it is difficult for the heat generated in the center of the semiconductor element to be transferred to the refrigerant via the fins, and the cooling of the center of the semiconductor element becomes insufficient. As a result, there is a problem that it is difficult to reduce the temperature of the center of the semiconductor element.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a heat sink and a semiconductor module in which the temperature of the central portion of a cooling target can be easily reduced.

[0007] In order to solve the above problems and achieve the purpose, the radiator according to the present invention is configured to have a refrigerant flow path for cooling a cooling object formed inside, and the radiator has: a first component having a first surface on which the cooling object is arranged and a second surface which is the back side of the first surface; a second component having a third surface facing the second surface and a fourth surface which is the back side of the third surface; a first partition wall which is arranged to contact the second surface of the first component and the third surface of the second component; and a plurality of first fins which are arranged to contact the second surface of the first component. The refrigerant flow path includes a first flow path formed between the first component and the second component. A plurality of first divided areas separated by the first partition wall are formed in the first flow path. In the first divided area, a plurality of first fins are arranged in a manner spaced apart from each other. The position when at least a portion of the first partition wall is projected onto the first surface or the position when at least a portion of the first fin is projected onto the first surface overlaps with the center of the cooling object.

[0008] Effects of the Invention

[0009] According to the present invention, there is an effect that the temperature of the central portion of the cooling target is easily lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an exploded perspective view showing the semiconductor module according to the first embodiment of the present invention.

[0011] Figure 2 This is a perspective view showing the first flow path forming plate according to the first embodiment.

[0012] Figure 3 It is a perspective view showing the second flow path forming plate according to the first embodiment.

[0013] Figure 4 It is a plan view showing the first flow channel forming plate according to the first embodiment.

[0014] Figure 5 is along Figure 4 FIG. 5 is a cross-sectional view of the semiconductor module taken along line VV.

[0015] Figure 6 is along Figure 4 A cross-sectional view of the semiconductor module taken along line VI-VI is shown.

[0016] Figure 7 is along Figure 4 A cross-sectional view of the semiconductor module taken along line VII-VII is shown.

[0017] Figure 8 It is a plan view showing a state where the first partition wall, the first fin, and the relay flow channel are projected onto the first surface.

[0018] Fig. 9 yes Figure 7 A partially enlarged cross-sectional view of a semiconductor module is shown.

[0019] Fig.10 This is an explanatory diagram for explaining the flow of the refrigerant in the first flow path of the radiator according to the first embodiment.

[0020] Fig.11 It is a diagram showing a heat sink of a semiconductor module according to Modification 1 of Embodiment 1 and is an explanatory diagram for explaining the flow direction of the refrigerant in the first flow path of the heat sink.

[0021] Fig.12 It is an exploded perspective view showing a semiconductor module according to a second modification of the first embodiment.

[0022] Fig.13 This is a partially enlarged cross-sectional view of a semiconductor module according to Modification 2 of Embodiment 1.

[0023] Fig.14 It is a diagram showing a semiconductor module according to Modification 3 of Embodiment 1 and is a plan view showing a state where a first partition wall, a first fin, and a relay flow path are projected onto a first surface.

[0024] Fig.15 It is a plan view showing a first flow channel forming plate of a semiconductor module according to Modification 4 of Embodiment 1.

[0025] Fig.16 It is a plan view showing a first flow channel forming plate of a semiconductor module according to a fifth modification of the first embodiment.

[0026] Fig.17 It is a plan view showing a first partition wall and a first fin of a semiconductor module according to a sixth modification of the first embodiment.

[0027] Fig.18 It is a plan view showing a second partition wall and a second fin of a semiconductor module according to a sixth modification of the first embodiment.

[0028] Fig.19 It is a diagram showing a semiconductor module according to a second embodiment of the present invention and is a plan view showing a state where a first partition wall, a first fin, and a relay channel are projected onto a first surface.

[0029] Fig. 20 It is an exploded perspective view showing a semiconductor module according to a third embodiment of the present invention.

[0030] Fig.21 It is a plan view showing a first flow channel forming plate of a semiconductor module according to a third embodiment.

[0031] Fig. 22 is along Fig.21 A cross-sectional view of the semiconductor module taken along line XXII-XXII is shown.

[0032] Fig.23 is along Fig.21 A cross-sectional view of the semiconductor module taken along line XXIII-XXIII is shown. DETAILED DESCRIPTION

[0033] Hereinafter, a heat sink and a semiconductor module according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiment.

[0034] Implementation Method 1

[0035] Figure 1 It is an exploded perspective view showing the semiconductor module 1 according to the first embodiment of the present invention. Figure 1 The arrows shown in the figure show the flow direction of the refrigerant. Figure 1 As shown, the semiconductor module 1 has a semiconductor element 2 as a cooling object and a heat sink 3. The semiconductor element 2 is, for example, a light emitting element or a power semiconductor. The light emitting element is, for example, a single laser element or an array laser element. The power semiconductor is formed on a substrate such as a Si substrate, a GaN substrate, or a SiC substrate. When the semiconductor element 2 is driven, heat is generated from the semiconductor element 2.

[0036] The heat sink 3 is a component for dissipating the heat generated by the semiconductor element 2. The heat sink 3 is formed by overlapping a heat conduction plate 31, a first flow path forming plate 32, a relay flow path forming plate 33, a second flow path forming plate 34 and a bottom plate 35. From the side close to the semiconductor element 2, the heat conduction plate 31, the first flow path forming plate 32, the relay flow path forming plate 33, the second flow path forming plate 34 and the bottom plate 35 are arranged in sequence. The heat conduction plate 31, the first flow path forming plate 32, the relay flow path forming plate 33, the second flow path forming plate 34 and the bottom plate 35 are all formed of a metal material with high thermal conductivity. Metal materials with high thermal conductivity are, for example, copper and aluminum. Preferably, each plate 31 to 35 is formed of the same metal material. The bonding method of each plate 31 to 35 is, for example, diffusion bonding. The shape of each plate 31 to 35 is not particularly limited, and is rectangular in this embodiment. In addition, in the present embodiment, the number of plates forming the radiator 3 is set to 5, but the number of plates forming the radiator 3 may be greater than or equal to 6. A refrigerant flow path 4 for the refrigerant to flow is formed inside the radiator 3. The refrigerant is, for example, pure water or antifreeze. The refrigerant flow path 4 will be described in detail later.

[0037] The heat conducting plate 31 as the first component has a first surface 31a on which the semiconductor element 2 is arranged, and a second surface 31b which is the back side of the first surface 31a. The heat of the semiconductor element 2 is directly conducted to the heat conducting plate 31. The first surface 31a is a surface facing the outside of the radiator 3. The second surface 31b is a surface facing the inside of the radiator 3. The joining method of the heat conducting plate 31 and the semiconductor element 2 is, for example, welding. A first opening 8 and a second opening 9 are formed in the heat conducting plate 31. The first opening 8 and the second opening 9 are arranged at a position away from the semiconductor element 2. The first opening 8 and the second opening 9 penetrate the heat conducting plate 31 in the plate thickness direction of the heat conducting plate 31. In the present embodiment, the first opening 8 becomes a refrigerant inlet for allowing the refrigerant to flow into the radiator 3. In the present embodiment, the second opening 9 becomes a refrigerant outlet for allowing the refrigerant to flow out of the radiator 3. In addition, the first opening 8 can also be set as a refrigerant outlet, and the second opening 9 can be set as a refrigerant inlet.

[0038] The first flow path forming plate 32 is a plate that forms the first flow path 5 between the heat conduction plate 31 and the relay flow path forming plate 33. The first peripheral wall 15, a plurality of first partition walls 12, and a plurality of first fins 13 are formed on the first flow path forming plate 32. The first peripheral wall 15, the first partition wall 12, and the first fin 13 will be described in detail later. A plurality of first division areas 51, a first common head area 52, and a third opening 10 are formed on the first flow path forming plate 32. The first division area 51, the first common head area 52, and the third opening 10 penetrate the first flow path forming plate 32 in the plate thickness direction of the first flow path forming plate 32. When viewed from above, the third opening 10 is arranged at a position overlapping with the first opening 8. The third opening 10 is connected to the first opening 8. The first partition wall 14b is arranged around the third opening 10. The third opening 10 is separated from the first partition area 51 and the first common end cover area 52 by the first partition wall 14b. As a result, the refrigerant flowing in the third opening 10 does not intersect with the refrigerant flowing in the first partition area 51 and the first common end cover area 52. The first partition area 51 and the first common end cover area 52 will be described in detail later.

[0039] The relay flow path forming plate 33 as the second component is a plate that forms the relay flow path 7. The relay flow path forming plate 33 has a third surface 33a facing the second surface 31b and a fourth surface 33b which is the back side of the third surface 33a. A plurality of relay flow paths 7 and a fourth opening 11 are formed on the relay flow path forming plate 33. The relay flow paths 7 and the fourth opening 11 penetrate the relay flow path forming plate 33 in the plate thickness direction of the relay flow path forming plate 33. When viewed from above, the fourth opening 11 is arranged at a position overlapping with the first opening 8 and the third opening 10. The fourth opening 11 is connected to the first opening 8 and the third opening 10. The relay flow path 7 will be described in detail later.

[0040] The second flow path forming plate 34 is a plate that forms the second flow path 6 between the bottom plate 35 and the relay flow path forming plate 33. A second peripheral wall 20, a plurality of second partition walls 17, and a plurality of second fins 18 are formed on the second flow path forming plate 34. The second peripheral wall 20, the second partition walls 17, and the second fins 18 will be described in detail later. A plurality of second divided areas 61 and a second common end area 62 are formed on the second flow path forming plate 34. The second divided areas 61 and the second common end area 62 penetrate the second flow path forming plate 34 in the plate thickness direction of the second flow path forming plate 34. The second divided areas 61 and the second common end area 62 will be described in detail later.

[0041] The bottom plate 35 as the third member is disposed on the opposite side to the heat transfer plate 31 so as to sandwich the first flow path forming plate 32, the relay flow path forming plate 33, and the second flow path forming plate 34. The bottom plate 35 is a flat plate without an opening.

[0042] Next, the refrigerant flow path 4 is described in detail. The refrigerant flow path 4 includes a first opening 8, a second opening 9, a third opening 10, a fourth opening 11, a first flow path 5, a second flow path 6, and a plurality of relay flow paths 7. The first flow path 5 is formed by a heat transfer plate 31, a relay flow path forming plate 33, and a first peripheral wall 15. The second flow path 6 is formed by a relay flow path forming plate 33, a bottom plate 35, and a second peripheral wall 20. The plurality of relay flow paths 7 connect the first flow path 5 and the second flow path 6.

[0043] The first opening 8, the third opening 10, and the fourth opening 11 are inflow passages for allowing the refrigerant to flow into the radiator 3. A pipe (not shown) for supplying the refrigerant into the radiator 3 is connected to the first opening 8. A pipe (not shown) for discharging the refrigerant to the outside of the radiator 3 is connected to the second opening 9. The first opening 8 and the second opening 9 are connected to a storage tank (not shown) via a pipe. By driving a pump (not shown), the refrigerant is supplied from the storage tank to the first opening 8 through the pipe.

[0044] Figure 2: This is an oblique view showing the first flow path forming plate 32 involved in Embodiment 1. A plurality of first divided areas 51 and a first common end area 52 are formed in the first flow path 5. The plurality of first divided areas 51 are separated by the first partition wall 12. In the present embodiment, a portion of the first flow path 5 is divided into four first divided areas 51 by four first partition walls 12. In addition to the function of dividing a portion of the first flow path 5 into a plurality of first divided areas 51, the first partition wall 12 also functions as a fin that conducts heat from the heat transfer plate 31 to the refrigerant. The four first partition walls 12 extend radially from one center point. The four first partition walls 12 are arranged at intervals of 90 degrees along the circumferential direction with one center point as the axis. When distinguishing the four first partition walls 12, they are referred to as first partition walls 12a, 12b, 12c, and 12d. When the four first divided regions 51 are divided, they are referred to as first divided regions 51a, 51b, 51c, and 51d.

[0045] The first partition wall 14a protruding to the opposite side of the first partition area 51b is formed at the front end of the first partition wall 12b. The front end of the first partition wall 12c is connected to the first partition wall 14b adjacent to the first partition area 51b. The first partition wall 14c protruding to the opposite side of the first partition area 51d is formed at the front end of the first partition wall 12d. The front end of the first partition wall 12a is connected to the first peripheral wall 15. The space separated by the first partition walls 12a, 12b and the first partition wall 14a is the first partition area 51a. The space separated by the first partition walls 12b, 12c and the first partition wall 14b is the first partition area 51b. The space separated by the first partition walls 12c, 12d and the first partition wall 14c is the first partition area 51c. The space separated by the first partition walls 12a, 12d and the first peripheral wall 15 is the first partition area 51d.

[0046] A plurality of first fins 13 are arranged in each first division area 51. The plurality of first fins 13 are arranged in parallel with each other at intervals. The first fins 13 in all first division areas 51 are arranged at equal intervals. The first fins 13 are formed in a flat plate shape. The first fins 13 protrude from each first partition wall 12 toward the first division area 51. One end of the first fin 13 along the length direction is connected to the first partition wall 12. The other end of the first fin 13 along the length direction faces the first common head area 52. The first fins 13 arranged in adjacent first division areas 51 protrude from first partition walls 12 that are different from each other. The length directions of the first fins 13 arranged in adjacent first division areas 51 are orthogonal to each other. A first inter-fin flow path 16 is formed between adjacent first fins 13 and first fins 13 and between adjacent first fins 13 and first partition walls 12. Furthermore, first inter-fin flow paths 16 are formed between adjacent first fins 13 and any of the first partition walls 14 a to 14 c and between adjacent first fins 13 and the first outer peripheral wall 15 .

[0047] The first common end region 52 is a region provided in a manner of surrounding the plurality of first divided regions 51. The first common end region 52 is connected to the first inter-fin flow passages 16 in each of the first divided regions 51. Figure 1 As shown in FIG. 1 , the first common end region 52 is arranged at a position overlapping with the second opening 9 in a plan view. The first common end region 52 communicates with the second opening 9 .

[0048] Figure 3 : This is an oblique view of the second flow path forming plate 34 involved in Embodiment 1. A plurality of second divided areas 61 and a second common end area 62 are formed in the second flow path 6. The plurality of second divided areas 61 are separated by a second partition wall 17. In the present embodiment, a portion of the second flow path 6 is divided into four second divided areas 61 by four second partition walls 17. The four second partition walls 17 extend radially from one center point. The four second partition walls 17 are arranged at 90 degree intervals along the circumferential direction with one center point as the axis. When the four second partition walls 17 are distinguished, they are referred to as second partition walls 17a, 17b, 17c, and 17d. When the four second divided areas 61 are distinguished, they are referred to as second divided areas 61a, 61b, 61c, and 61d.

[0049] The second partition wall 17b is formed with a second partition wall 19a protruding to the opposite side of the second partition area 61b. The front end of the second partition wall 17c is connected to the second partition wall 19b adjacent to the second partition area 61b. The front end of the second partition wall 17d is formed with a second partition wall 19c protruding to the opposite side of the second partition area 61d. The front end of the second partition wall 17a is connected to the second peripheral wall 20. The space separated by the second partition walls 17a, 17b and the second partition wall 19a is the second partition area 61a. The space separated by the second partition walls 17b, 17c and the second partition wall 19b is the second partition area 61b. The space separated by the second partition walls 17c, 17d and the second partition wall 19c is the second partition area 61c. The space separated by the second partition walls 17a, 17d and the second peripheral wall 20 is the second partition area 61d.

[0050] A plurality of second fins 18 are arranged in each second divided area 61. The plurality of second fins 18 are arranged in parallel with each other at intervals. The second fins 18 in all second divided areas 61 are arranged at equal intervals. The second fins 18 are formed in a flat plate shape. The second fins 18 protrude from each second partition wall 17 toward the second divided area 61. One end of the second fin 18 along the length direction is connected to the second partition wall 17. The other end of the second fin 18 along the length direction faces the second common head area 62. The second fins 18 arranged in adjacent second divided areas 61 protrude from second partition walls 17 that are different from each other. The longitudinal directions of the second fins 18 arranged in adjacent second divided areas 61 are orthogonal to each other. A second inter-fin flow path 21 is formed between adjacent second fins 18 and second fins 18 and between adjacent second fins 18 and second partition walls 17. In addition, second inter-fin flow paths 21 are formed between the adjacent second fins 18 and any of the second partition walls 19 a to 19 c and between the adjacent second fins 18 and the second outer peripheral wall 20 .

[0051] The second common end region 62 is a region provided in a manner of surrounding the plurality of second divided regions 61. The second common end region 62 is connected to the second inter-fin flow passages 21 in each of the second divided regions 61. Figure 1 As shown, in a plan view, the second common end region 62 is arranged at a position overlapping with the first opening 8, the third opening 10, and the fourth opening 11. The first opening 8, the third opening 10, the fourth opening 11, and the second common end region 62 are connected to each other.

[0052] Four relay flow paths 7 are arranged at 90-degree intervals along the circumference with one center point as the axis. The four relay flow paths 7 are arranged at equal intervals. When distinguishing the four relay flow paths 7, they are referred to as relay flow paths 7a, 7b, 7c, and 7d. The shape of the relay flow path 7 is not particularly limited, and in the present embodiment, it is an elongated rectangular shape. The length directions of adjacent relay flow paths 7 are orthogonal to each other. When viewed from above, the first segmentation area 51a, the second segmentation area 61a, and the relay flow path 7a are arranged at positions that overlap with each other. The length direction of the first fin 13 in the first segmentation area 51a is parallel to the length direction of the second fin 18 in the second segmentation area 61a. When viewed from above, the first segmentation area 51b, the second segmentation area 61b, and the relay flow path 7b are arranged at positions that overlap with each other. The length direction of the first fin 13 in the first segmentation area 51b is parallel to the length direction of the second fin 18 in the second segmentation area 61b. When viewed from above, the first segmented area 51c, the second segmented area 61c, and the relay flow path 7c are arranged at positions overlapping each other. The length direction of the first fin 13 in the first segmented area 51c and the length direction of the second fin 18 in the second segmented area 61c are parallel to each other. When viewed from above, the first segmented area 51d, the second segmented area 61d, and the relay flow path 7d are arranged at positions overlapping each other. The length direction of the first fin 13 in the first segmented area 51d and the length direction of the second fin 18 in the second segmented area 61d are parallel to each other.

[0053] Figure 4 1 is a plan view showing the first flow channel forming plate 32 according to the first embodiment. Figure 5 is along Figure 4 1 is a cross-sectional view of the semiconductor module 1 taken along line VV. Figure 6 is along Figure 4 VI-VI line is a cross-sectional view of the semiconductor module 1 shown. Figure 7 is along Figure 4 A cross-sectional view of the semiconductor module 1 along line VII-VII is shown. Figure 4 In FIG. 1 , for convenience of explanation, the semiconductor element 2 is shown by a dotted line. Figure 4 For convenience of explanation, only the first flow path forming plate 32 in the radiator 3 is shown. Figure 5 to Figure 7 The position of the cross section of the semiconductor module 1 is shown. Figure 5As shown, the first partition wall 12 is provided to contact the second surface 31b of the heat conducting plate 31 and the third surface 33a of the relay flow path forming plate 33. The first peripheral wall 15 is provided to contact the second surface 31b of the heat conducting plate 31 and the third surface 33a of the relay flow path forming plate 33. The second partition wall 17 is provided to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35. The second peripheral wall 20 is provided to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35.

[0054] like Figure 6 and Figure 7 As shown, the first fin 13 is arranged to contact the second surface 31b of the heat transfer plate 31 and the third surface 33a of the relay flow path forming plate 33. The second fin 18 is arranged to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35. Figure 7 As shown, the first inter-fin flow path 16 and the second inter-fin flow path 21 are connected via the relay flow path 7. The width of the first partition wall 12 is the same as the width of the second partition wall 17. The width of the first fin 13 is the same as the width of the second fin 18. The setting interval of the first fin 13 is the same as the setting interval of the second fin 18. In addition, in consideration of reducing the pressure loss of the refrigerant, improving the cooling effect brought by the refrigerant, and suppressing the corrosion of the first fin 13, etc., it is preferred to set the average flow velocity of the refrigerant flowing in the relay flow path 7 and the average flow velocity of the refrigerant flowing in the first inter-fin flow path 16 to be approximately the same. For example, if the opening width of the relay flow path 7 is set to about half the height of the first fin 13, the average flow velocity of the refrigerant flowing in the relay flow path 7 and the average flow velocity of the refrigerant flowing in the first inter-fin flow path 16 can be set to be approximately the same.

[0055] Figure 8 3 is a plan view showing a state where the first partition wall 12, the first fin 13, and the relay flow path 7 are projected onto the first surface 31a. Figure 8 In order to facilitate the description, the first partition wall 12 and the first fin 13 are shown by solid lines, and the relay flow path 7 and the semiconductor element 2 are shown by dotted lines. Figure 8In order to facilitate the description, the heat transfer plate 31 is depicted as being extremely small. The positions when a portion of the first partition wall 12, a portion of the first fin 13, and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a overlap with the semiconductor element 2. In the present embodiment, the center points of the four first partition walls 12 are aligned with the center of the semiconductor element 2. The position when a portion of the first partition wall 12 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2 and the periphery of the center of the semiconductor element 2. The positions when a portion of the first fin 13 and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a overlap with the periphery of the center of the semiconductor element 2. In addition, in the present embodiment, the position when a portion of the first partition wall 12 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2, but the position when a portion of the first fin 13 is projected onto the first surface 31a may also overlap with the center of the semiconductor element 2.

[0056] If the relay flow path 7, the first division area 51, and the first fin 13 are projected onto the first surface 31a, the relay flow path 7 is disposed one at each position overlapping with each of the plurality of first division areas 51, and the relay flow path 7 is formed elongated in a manner to cross the plurality of first fins 13. The length direction of the relay flow path 7 is orthogonal to the length direction of the first fin 13. The relay flow path 7 is disposed at a position overlapping with a root portion of the first fin 13 connected to the first partition wall 12.

[0057] As described above, the refrigerant flow path 4 is formed in a hierarchical manner by having a first flow path 5, a second flow path 6, and a relay flow path 7, wherein the first flow path 5 is closest to the first surface 31a on which the semiconductor element 2 is arranged, the second flow path 6 is formed away from the first surface 31a in the normal direction of the first surface 31a compared to the first flow path 5, and the relay flow path 7 is located between the first flow path 5 and the second flow path 6 and connects the first flow path 5 and the second flow path 6. The first flow path 5 has a second surface 31b located on the first surface 31a side and a third surface 33a opposite to the second surface 31b as an inner surface. A plurality of first divided areas 51 separated by a first partition wall 12 provided between the second surface 31b and the third surface 33a are formed in the first flow path 5. The first divided area 51 has a plurality of first fins 13 formed in a manner of being arranged at intervals from each other and extending from the first partition wall 12. The position when at least a portion of the first partition wall 12 is projected onto the first surface 31a or the position when at least a portion of the first fin 13 is projected onto the first surface 31a overlaps with the center of the region of the first surface 31a where the semiconductor element 2 is provided. If the relay flow path 7, the first segmented area 51, and the first fin 13 are projected onto the first surface 31a, at least one relay flow path 7 is disposed at each position overlapping with each of the plurality of first segmented areas 51, and the relay flow path 7 is formed elongated in a manner to cross the plurality of first fins 13 along the first partition wall 12. In the heat sink 3, the refrigerant flows between the first flow path 5 and the second flow path 6 via the relay flow path 7.

[0058] Next, refer to Figure 1, the flow direction of the refrigerant is described. The refrigerant flowing into the radiator 3 from the first opening 8 flows into the second common head area 62 through the third opening 10 and the fourth opening 11. Next, the refrigerant flows from the second common head area 62 into the second inter-fin flow path 21 in each second divided area 61. Next, the refrigerant flows from the second inter-fin flow path 21 through the relay flow path 7 into the first inter-fin flow path 16 in each first divided area 51. At this time, the refrigerant in the second inter-fin flow path 21 in the second divided area 61a flows into the first inter-fin flow path 16 in the first divided area 51a through the relay flow path 7a. The refrigerant in the second inter-fin flow path 21 in the second divided area 61b flows into the first inter-fin flow path 16 in the first divided area 51b through the relay flow path 7b. The refrigerant in the second inter-fin flow path 21 in the second divided area 61c flows into the first inter-fin flow path 16 in the first divided area 51c through the relay flow path 7c. The refrigerant in the second inter-fin flow path 21 in the second divided area 61d flows into the first inter-fin flow path 16 in the first divided area 51d through the relay flow path 7d. Thereafter, the refrigerant flows from the first inter-fin flow path 16 in each first divided area 51 into the first common end region 52. Next, the refrigerant flows out of the first common end region 52 through the second opening 9 to the outside of the radiator 3.

[0059] Next, the effects of the semiconductor module 1 according to the present embodiment will be described.

[0060] like Figure 7 As shown, the heat generated by the semiconductor element 2 is conducted to the heat transfer plate 31. The heat conducted to the heat transfer plate 31 is conducted to the first partition wall 12 and the first fin 13. If the refrigerant flows in the first flow path 5, heat exchange is performed between the heat transfer plate 31 and the refrigerant, between the first partition wall 12 and the refrigerant, and between the first fin 13 and the refrigerant. That is, the refrigerant absorbs the heat conducted to the heat transfer plate 31, the first partition wall 12, and the first fin 13. As a result, the semiconductor element 2 is cooled by the refrigerant via the heat transfer plate 31, the first partition wall 12, and the first fin 13. Figure 8 As shown, in the present embodiment, the position when a part of the first partition wall 12 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2. In addition, the position when a part of the first fin 13 is projected onto the first surface 31a overlaps with the periphery of the center of the semiconductor element 2. Therefore, the heat generated at the center of the semiconductor element 2 is easily conducted to the first partition wall 12 and the first fin 13 via the heat transfer plate 31. Since the heat conducted to the first partition wall 12 and the first fin 13 is absorbed by the refrigerant flowing in the first inter-fin flow path 16, the cooling effect on the center of the semiconductor element 2 becomes higher.

[0061] Reference Figure 1 and Fig. 9 , illustrating the cooling effect of the refrigerant on the semiconductor element 2. Fig. 9 yes Figure 7 FIG. 1 is a partial enlarged cross-sectional view of the semiconductor module 1 shown in FIG. 1 . Generally, the temperature of the heat generated by the semiconductor element 2 increases as it approaches the center of the semiconductor element 2. Therefore, an imbalance occurs in the temperature distribution of the semiconductor element 2 and the heat transfer plate 31. In this embodiment, if the temperature of the semiconductor element 2 is Figure 1 The refrigerant flows into the first opening 8 shown in FIG. Fig. 9 The refrigerant flowing into the first inter-fin flow path 16 through the relay flow path 7 in the second inter-fin flow path 21 shown collides with the second surface 31b of the heat transfer plate 31 at a position close to the center of the semiconductor element 2. Therefore, the temperature of the center of the semiconductor element 2 can be reduced, and the uneven temperature distribution at the semiconductor element 2 can be alleviated. Fig. 9 As shown, if the refrigerant flows into the first inter-fin flow path 16, a vortex 23 is generated in the first inter-fin flow path 16 near the joint 22 between the heat transfer plate 31 and the first partition wall 12, and the refrigerant is stagnated in the first inter-fin flow path 16. In the portion where the refrigerant is stagnant, the cooling effect of the heat transfer plate 31 brought by the refrigerant is reduced. In this regard, in this embodiment, since the refrigerant collides with the second surface 31b of the heat transfer plate 31 near the stagnant portion, the temperature rise of the heat transfer plate 31 caused by the stagnation of the refrigerant can be suppressed.

[0062] like Figure 8 As shown, in this embodiment, if the relay flow path 7, the first segmented area 51, and the first fin 13 are projected onto the first surface 31a, the relay flow path 7 is formed to be elongated in a manner to cross the plurality of first fins 13. Therefore, the flow path area of ​​the relay flow path 7 becomes smaller, and the flow velocity of the refrigerant increases when passing through the relay flow path 7. As a result, the refrigerant in the state of increased flow velocity collides with the second surface 31b of the heat transfer plate 31 at a position close to the center of the semiconductor element 2, so that the temperature of the center of the semiconductor element 2 can be further reduced, and the uneven temperature distribution at the semiconductor element 2 can be alleviated.

[0063] Here, Fig. 9The wall formed by overlapping the first partition wall 12, the second partition wall 17 and the relay flow path forming plate 33 shown is set as a central partition wall 24. The relay flow path 7 is configured to be adjacent to the middle part of the height direction of the central partition wall 24. In this way, the flow direction of the refrigerant from the second inter-fin flow path 21 toward the first inter-fin flow path 16 can be changed to a direction perpendicular to the heat transfer plate 31 at a position as close to the heat transfer plate 31 as possible. Therefore, the refrigerant after passing through the relay flow path 7 collides with the second surface 31b of the heat transfer plate 31 in a state close to perpendicular to the heat transfer plate 31. Thereby, the amount of vortex 23 generated can be reduced. Therefore, the temperature of the center part of the semiconductor element 2 can be further reduced, and the uneven temperature distribution at the semiconductor element 2 can be alleviated.

[0064] Reference Fig.10 , the effects of the semiconductor module 1 according to this embodiment will be further described. Fig.10 This is an explanatory diagram for explaining the flow of the refrigerant in the first flow path 5 of the radiator 3 according to the first embodiment.

[0065] like Fig.10 As shown, in the heat sink 3 according to the present embodiment, the first fins 13 arranged in the adjacent first divided regions 51 protrude from the first partition walls 12 that are different from each other. The length directions of the first fins 13 arranged in the adjacent first divided regions 51 are orthogonal to each other. The length directions of the adjacent relay flow paths 7 are orthogonal to each other. The four relay flow paths 7 are arranged at equal intervals. The refrigerant in the first inter-fin flow path 16 in the first divided region 51a is Fig.10 The refrigerant in the first inter-fin flow path 16 in the first divided area 51b flows from the left side to the right side of the paper. Fig.10 The refrigerant in the first inter-fin flow path 16 in the first divided area 51c flows from the bottom of the paper to the top. Fig.10 The refrigerant in the first inter-fin flow path 16 in the first divided area 51d flows from the right side of the paper to the left side. Fig.10 That is, in this embodiment, the refrigerant flows in the first inter-fin flow path 16 toward Fig.10 The heat evenly flows above, below, to the left and to the right of the paper, thereby alleviating the uneven temperature distribution at the semiconductor element 2. In addition, since the four relay flow paths 7 are arranged at equal intervals, Fig. 9 As shown, when the coolant collides with the second surface 31 b of the heat transfer plate 31 at a position close to the center of the semiconductor element 2 , the cooling effect on the heat transfer plate 31 by the coolant also becomes uniform.

[0066] like Fig.10As shown, in the present embodiment, the relay flow path 7 is arranged at a position overlapping with the root portion of the first fin 13 connected to the first partition wall 12. Therefore, the refrigerant flowing from the relay flow path 7 into the first inter-fin flow path 16 flows from the vicinity of the first partition wall 12 toward the first common head area 52. That is, a portion of the refrigerant flowing in the first inter-fin flow path 16 first contacts the portion of the heat transfer plate 31 close to the center of the semiconductor element 2, and then contacts the portion of the heat transfer plate 31 close to the periphery of the semiconductor element 2. As a result, more heat of the portion of the heat transfer plate 31 close to the center of the semiconductor element 2 can be absorbed by the refrigerant, so that the uneven temperature distribution at the semiconductor element 2 can be alleviated. In addition, as for the refrigerant flowing in the first inter-fin flow path 16, the more heat is absorbed toward the periphery of the first flow path forming plate 32, the temperature rises. Thus, the cooling effect of the refrigerant on the outer periphery of the semiconductor element 2 is relatively low compared to the cooling effect of the refrigerant on the central portion of the semiconductor element 2 , and thus the unevenness of the temperature distribution in the semiconductor element 2 can be alleviated.

[0067] In the present embodiment, since the cooling effect on the center of the semiconductor element 2 is higher than that on the periphery of the semiconductor element 2, even if the length of the first inter-fin flow path 16 is shortened, for example, the length of the first inter-fin flow path 16 is set to half, the cooling effect of the refrigerant on the center of the semiconductor element 2 can be fully exerted. In addition, by shortening the length of the first inter-fin flow path 16, the pressure loss of the refrigerant in the first inter-fin flow path 16 can be reduced.

[0068] like Figure 8As shown, in the present embodiment, four first divided areas 51 separated by four first partition walls 12 are formed in the first flow path 5. When a part of the first divided area 51 is projected onto the first surface 31a, the position overlaps with the semiconductor element 2. In addition, if the relay flow path 7, the first divided area 51 and the first fin 13 are projected onto the first surface 31a, one relay flow path 7 is arranged at each position overlapping with each of the plurality of first divided areas 51. In this way, the refrigerant flows from the relay flow path 7 into the first divided area 51, and in each of the first divided areas 51, the refrigerant collides with the second surface 31b of the heat transfer plate 31. As a result, the number of locations where the refrigerant collides with the second surface 31b of the heat transfer plate 31 increases, and the cooling effect of the refrigerant on the semiconductor element 2 becomes higher. According to the experiment conducted by the inventors, if a part of the first flow path 5 is divided into a plurality of first divided areas 51, the cooling effect of the semiconductor element 2 brought by the refrigerant becomes higher than the case where the straight fins are arranged without providing the first partition wall 12, that is, the case where the part of the first flow path 5 is not divided into a plurality of first divided areas 51. In addition, the condition of the experimental result is that the average flow velocity of the refrigerant flowing in the first inter-fin flow path 16 is the same when the part of the first flow path 5 is divided into a plurality of first divided areas 51 and when the part of the first flow path 5 is not divided into a plurality of first divided areas 51.

[0069] like Figure 2 As shown, in this embodiment, a first common end cap region 52 is formed in the first flow path 5 so as to surround the first segmented region 51, and the first common end cap region 52 is connected to the first inter-fin flow paths 16 in each first segmented region 51. In this way, since all the first inter-fin flow paths 16 and the first common end cap region 52 in each first segmented region 51 are arranged at the same level, the heat sink 3 can be thinned as a whole, thereby realizing miniaturization of the heat sink 3. Figure 3 As shown, in the present embodiment, a second common end cap region 62 is formed in the second flow path 6 so as to surround the second segmented region 61, and the second common end cap region 62 is connected to the second inter-fin flow paths 21 in each second segmented region 61. In this way, since all the second inter-fin flow paths 21 and the second common end cap region 62 in each second segmented region 61 are arranged at the same level, the heat sink 3 can be thinned as a whole, thereby realizing miniaturization of the heat sink 3.

[0070] Since the heat sink 3 and the semiconductor element 2 have different thermal expansion coefficients and Young's moduli, the heat generated when the heat sink 3 and the semiconductor element 2 are joined increases the warpage, stress, and strain generated between the heat sink 3 and the semiconductor element 2. As a result, there are problems such as damage to the semiconductor element 2 and poor joining between the heat sink 3 and the semiconductor element 2. Since the heat sink 3 can be made thinner as a whole as in this embodiment, the warpage, stress, and strain generated between the heat sink 3 and the semiconductor element 2 can be reduced, and the occurrence of the above-mentioned problems can be suppressed.

[0071] Figure 1 The greater the number of the first divided areas 51 shown, the higher the cooling effect on the semiconductor element 2. On the other hand, the greater the number of the first divided areas 51, the higher the manufacturing cost of the heat sink 3. Generally, the heat sink 3 having the refrigerant flow path 4 is manufactured by joining and cutting a plurality of parts. The greater the number of the first divided areas 51, the greater the number of joining and cutting, and thus the higher the manufacturing cost of the heat sink 3. Therefore, as in the present embodiment, if a part of the first flow path 5 is divided into four first divided areas 51, it is possible to balance the improvement of the cooling effect on the semiconductor element 2 brought by the refrigerant and the suppression of the manufacturing cost of the heat sink 3 in a well-balanced manner.

[0072] like Figure 1 As shown, in this embodiment, the first fin 13 is formed in a flat plate shape, and a plurality of first fins 13 are arranged in parallel with each other. Therefore, the design and manufacture of the first inter-fin flow path 16 becomes easy. In addition, in this embodiment, the second fin 18 is formed in a flat plate shape, and a plurality of second fins 18 are arranged in parallel with each other. Therefore, the design and manufacture of the second inter-fin flow path 21 becomes easy.

[0073] In addition, the cooling object can be any electronic device that generates heat, and is not limited to the semiconductor element 2. For example, it can also be a capacitor. In the present embodiment, diffusion bonding is used as the bonding method of each plate 31 to 35, but the bonding method of each plate 31 to 35 is not particularly limited. For example, it can also be brazing. The heat conduction plate 31, the first flow path forming plate 32, the relay flow path forming plate 33 and the second flow path forming plate 34 are each made by forming an opening in a flat plate. The processing method for forming the opening is punching, cutting, wire cutting, etching, etc. Regarding the manufacturing method of the heat sink 3, for example, the manufacturing method disclosed in Japanese Patent Publication No. 2007-205694 can be used. That is, the heat sink 3 can also be made by stacking and bonding a plurality of thin plates. In this way, when the heat sink 3 is made, for example, each of the first flow path forming plate 32, the relay flow path forming plate 33 and the second flow path forming plate 34 is formed by a plurality of thin plates. In the present embodiment, the heat sink 3 is formed by a plurality of plates 31 to 35, but the heat sink 3 may be formed integrally using a 3D printer or the like. In the case where the heat sink 3 is formed integrally, the components are not actually separated, but the region having the first surface 31a and the second surface 31b is treated as the first component. In addition, in the case where the heat sink 3 is formed integrally, the region having the third surface 33a and the fourth surface 33b is treated as the second component. In addition, in the case where the heat sink 3 is formed integrally, the region forming the second flow path 6 between the second component is treated as the third component. In the present embodiment, four first division areas 51 are provided, but a plurality of first division areas 51 other than four may be provided. The number of the second division areas 61 and the relay flow paths 7 may be appropriately changed to match the number of the first division areas 51. In the present embodiment, a plurality of first fins 13 are arranged in parallel, but they may not be arranged in parallel. In the present embodiment, a plurality of second fins 18 are arranged in parallel, but they may not be arranged in parallel. In the present embodiment, the radiator 3 is provided with a second flow path forming plate 34 and a bottom plate 35, and the refrigerant flow path 4 includes a second flow path 6 and a plurality of relay flow paths 7. However, the second flow path forming plate 34 and the bottom plate 35 may be omitted, and the refrigerant flow path 4 does not include a second flow path 6 and a plurality of relay flow paths 7. In such a configuration, the relay flow path forming plate 33 is provided as a flat plate without an opening, similarly to the bottom plate 35 involved in the present embodiment. In addition, the third opening 10 of the first flow path forming plate 32 is omitted. In addition, the first opening 8 is provided at a position overlapping with the first segmentation area 51 when viewed from above. For example, one first opening 8 may be provided at each position overlapping with each of the plurality of first segmentation areas 51. In the present embodiment, one relay flow path 7 is provided at each position overlapping with each of the plurality of first segmentation areas 51, but two or more may be provided at each position.In addition, a single relay flow path 7 may be formed on the relay flow path forming plate 33, and the single relay flow path 7 may be arranged at a position overlapping with all the first divided areas 51. In the present embodiment, the relay flow path 7 is arranged at a position overlapping with the root portion of the first fin 13 connected to the first partition wall 12, but as long as the relay flow path 7 is at a position overlapping with the first fin 13, the position of the relay flow path 7 relative to the first fin 13 may be appropriately changed.

[0074] Next, refer to Fig.11 , a semiconductor module 1 according to a first modification of the first embodiment will be described. Fig.11 1 is a diagram showing a heat sink 3 of a semiconductor module 1 according to a first modification of the first embodiment, and is an explanatory diagram for explaining the flow direction of the refrigerant in the first flow path 5 of the heat sink 3. In the first modification, the same reference numerals are given to the parts that are repeated in the first embodiment, and the description thereof is omitted. The flow direction of the refrigerant in the first flow path 5 of the first modification is different from that of the first embodiment.

[0075] like Fig.11 As shown, with respect to the radiator 3 involved in this variation, a portion of the first flow path 5 is divided into four first divided areas 51 by four first partition walls 12. The first fins 13 arranged in the adjacent first divided areas 51c, 51d do not protrude from the first partition walls 12 that are different from each other. That is, the first fins 13 arranged in the adjacent first divided areas 51c, 51d protrude from the same first partition wall 12d in opposite directions to each other. The length directions of the first fins 13 arranged in the first divided areas 51a, 51c, 51d are parallel to each other. If the relay flow path 7 is arranged at a position overlapping with the root portion of the first fin 13 connected to the first partition wall 12, the three relay flow paths 7a, 7c, 7d are parallel to each other. The four relay flow paths 7 are arranged at unequal intervals. The refrigerant in the first inter-fin flow path 16 in the first divided areas 51a, 51d is Fig.11 The refrigerant in the first inter-fin flow path 16 in the first divided area 51b flows from the left side to the right side of the paper. Fig.11 The refrigerant in the first inter-fin flow path 16 in the first divided area 51c flows from the bottom of the paper to the top. Fig.11Flows from the right side of the paper to the left side. In this modification, similarly, the position when a part of the first partition wall 12 is projected onto the first surface 31a (not shown) overlaps with the center of the semiconductor element 2. In addition, the position when a part of the first fin 13 is projected onto the first surface 31a overlaps with the periphery of the center of the semiconductor element 2. Therefore, the heat generated in the center of the semiconductor element 2 is easily conducted to the first partition wall 12 and the first fin 13 via the heat conduction plate 31. Since the heat conducted to the first partition wall 12 and the first fin 13 is absorbed by the refrigerant flowing in the first inter-fin flow path 16, the cooling effect on the center of the semiconductor element 2 becomes higher.

[0076] Next, refer to Fig.12 and Fig.13 , a semiconductor module 1 according to a second modification of the first embodiment will be described. Fig.12 It is an exploded perspective view showing a semiconductor module 1 according to a second modification of the first embodiment. Fig.13 This is a partially enlarged cross-sectional view of a semiconductor module 1 according to a second modification of Embodiment 1. In Modification 2, portions that overlap with those in Embodiment 1 are denoted by the same reference numerals and description thereof is omitted. Modification 2 is different from Embodiment 1 in the flow direction of the refrigerant.

[0077] like Fig.12 As shown, in this modification, the refrigerant is made to flow into the radiator 3 from the second opening 9. The refrigerant flowing into the radiator 3 from the second opening 9 flows into the first common head region 52. Next, the refrigerant flows from the first common head region 52 into the first inter-fin flow path 16 in each first divided region 51. Next, the refrigerant flows from the first inter-fin flow path 16 through the relay flow path 7 into the second inter-fin flow path 21 in each second divided region 61. At this time, the refrigerant in the first inter-fin flow path 16 in the first divided region 51a flows into the second inter-fin flow path 21 in the second divided region 61a through the relay flow path 7a. The refrigerant in the first inter-fin flow path 16 in the first divided region 51b flows into the second inter-fin flow path 21 in the second divided region 61b through the relay flow path 7b. The refrigerant in the first inter-fin flow path 16 in the first divided area 51c flows into the second inter-fin flow path 21 in the second divided area 61c through the relay flow path 7c. The refrigerant in the first inter-fin flow path 16 in the first divided area 51d flows into the second inter-fin flow path 21 in the second divided area 61d through the relay flow path 7d. Thereafter, the refrigerant flows from the second inter-fin flow path 21 in each second divided area 61 into the second common end region 62. Next, the refrigerant flows out of the second common end region 62 to the outside of the radiator 3 through the fourth opening 11, the third opening 10, and the first opening 8.

[0078] Next, refer to Fig.13Next, the flow direction of the refrigerant in the first inter-fin flow passage 16 and the relay flow passage 7 will be described. The refrigerant having flowed into the first inter-fin flow passage 16 flows toward the first partition wall 12 . Fig.13 The refrigerant shown in the figure flows through the first inter-fin flow path 16 from Fig.13 The refrigerant flows from the left side of the paper to the right side and collides with the first partition wall 12. The refrigerant passes through the first partition wall 12 and changes its direction to Fig.13 , and flows into the relay flow path 7 below the paper surface. At this time, a vortex 23 is generated near the joint 22 of the heat transfer plate 31 and the first partition wall 12, but the faster the flow rate of the refrigerant flowing in the first inter-fin flow path 16, the smaller the scale of the vortex 23. Therefore, the influence of the vortex 23 on the temperature rise of the heat transfer plate 31 and the first partition wall 12 is suppressed. In addition, if the refrigerant collides with the first partition wall 12, the boundary layer of the refrigerant becomes thinner, so the first partition wall 12 can be efficiently cooled. Since the first partition wall 12 is arranged near the center of the semiconductor element 2, it is a part where the heat of the center of the semiconductor element 2 is easily conducted through the heat transfer plate 31. By making the refrigerant collide with the first partition wall 12, the first partition wall 12 can be concentratedly cooled, so the temperature of the center of the semiconductor element 2 can be efficiently reduced. In addition, the heat generated by the semiconductor element 2 is conducted to the refrigerant via the heat transfer plate 31, the first partition wall 12 and the first fin 13. By allowing a refrigerant with a sufficient flow rate relative to the heat generated by the semiconductor element 2 to flow through the refrigerant flow path 4, a rise in the temperature of the refrigerant caused by the heat conducted from the semiconductor element 2 is suppressed. Therefore, the greater the flow rate of the refrigerant, the more efficiently the center of the semiconductor element 2 can be cooled, and thus the uneven temperature distribution at the semiconductor element 2 can be alleviated.

[0079] Next, refer to Fig.14 , a semiconductor module 1 according to a third modification of the first embodiment will be described. Fig.14 1 is a diagram showing a semiconductor module 1 according to a third modification of the first embodiment, and is a plan view showing a state where the first partition wall 12, the first fin 13, and the relay channel 7 are projected onto the first surface 31a. Fig.14 In order to facilitate the description, the first partition wall 12 and the first fin 13 are shown by solid lines, and the relay flow path 7 and the semiconductor element 2 are shown by dotted lines. Fig.14 In order to facilitate the description, the heat transfer plate 31 is depicted as being extremely small. In Modification 3, the same reference numerals are given to the parts that overlap with those in Embodiment 1, and the description thereof is omitted. Modification 3 differs from Embodiment 1 in that the flow passage widths of the first inter-fin flow passages 16 are made uneven.

[0080] A plurality of first inter-fin flow paths 16 are provided in each first divided region 51. In each first divided region 51, the flow path widths of the first inter-fin flow paths 16 are not uniform. The flow path width of the first inter-fin flow paths 16 is narrow at a position close to the center of the semiconductor element 2 and wide at a position close to the periphery of the semiconductor element 2. In this variation, six first inter-fin flow paths 16 are provided in each first divided region 51. The flow path widths of the first inter-fin flow paths 16 from the one close to the center of the semiconductor element 2 to the fourth inter-fin flow path 16 are the same. Hereinafter, these four first inter-fin flow paths 16 are sometimes referred to as center-side inter-fin flow paths 16A. The flow path widths of the remaining two first inter-fin flow paths 16 are the same. Hereinafter, these two first inter-fin flow paths 16 are sometimes referred to as peripheral-side inter-fin flow paths 16B. The flow path width of the peripheral-side inter-fin flow path 16B is wider than the flow path width of the center-side inter-fin flow path 16A. In each of the first divided regions 51 , the flow path lengths of the first inter-fin flow paths 16 are the same.

[0081] In this variation, three relay flow paths 7 are arranged at positions overlapping with the plurality of first divided regions 51, respectively. In each first divided region 51, the flow path area of ​​the relay flow path 7 is large at a position close to the center of the semiconductor element 2 and small at a position close to the periphery of the semiconductor element 2. The flow path area of ​​the relay flow path 7 closest to the center of the semiconductor element 2 is larger than the flow path areas of the remaining two relay flow paths 7. Below, the relay flow path 7 closest to the center of the semiconductor element 2 is sometimes referred to as the center-side relay flow path 7A, and the remaining two relay flow paths 7 are sometimes referred to as the peripheral-side relay flow paths 7B. The flow path areas of the two peripheral-side relay flow paths 7B are the same. The peripheral-side relay flow paths 7B are connected to the peripheral-side inter-fin flow paths 16B one by one. Although not shown in the figure, the second inter-fin flow path 21 also has the same structure as the first inter-fin flow path 16. That is, the second inter-fin flow path 21 having a narrow flow path width is provided near the center of the semiconductor element 2 , and the second inter-fin flow path 21 having a wide flow path width is provided near the outer periphery of the semiconductor element 2 .

[0082] In this modification, by making the flow path width of the first inter-fin flow path 16 narrow at a position close to the center of the semiconductor element 2 and wide at a position close to the periphery of the semiconductor element 2, the first fins 13 can be arranged densely at a position close to the center of the semiconductor element 2, and more first fins 13 can be arranged. Therefore, at a position close to the center of the semiconductor element 2 compared to the periphery of the semiconductor element 2, the heat dissipation area formed by the first fin 13 can be increased, and the part where the refrigerant collides with the second surface 31b of the heat transfer plate 31 can be increased. As a result, the temperature of the center of the semiconductor element 2 can be further reduced, and the uneven temperature distribution at the semiconductor element 2 can be alleviated. In addition, the flow path width of the first inter-fin flow path 16 can be set to be equal as in Embodiment 1, and the relay flow path 7 with a large flow path area can be arranged at a position close to the center of the semiconductor element 2 as in this modification, and the relay flow path 7 with a small flow path area can be arranged at a position close to the periphery of the semiconductor element 2. Thus, the flow rate of the refrigerant increases at a position closer to the center of the semiconductor element 2 than at the periphery of the semiconductor element 2. Therefore, the temperature of the center of the semiconductor element 2 can be lowered than at the periphery of the semiconductor element 2, and the uneven temperature distribution in the semiconductor element 2 can be alleviated.

[0083] Furthermore, if the flow path width of the first inter-fin flow path 16 is made narrow at a position close to the center of the semiconductor element 2 and wide at a position close to the periphery of the semiconductor element 2, the pressure loss of the refrigerant in the first inter-fin flow path 16 with a narrow flow path width and the first inter-fin flow path 16 with a wide flow path width are different, and there is a possibility of biased flow. In this regard, in this modification, by making the flow path area of ​​the relay flow path 7 large at a position close to the center of the semiconductor element 2 and small at a position close to the periphery of the semiconductor element 2, it is possible to adjust the pressure loss of the refrigerant in the first inter-fin flow path 16 with a narrow flow path width and the first inter-fin flow path 16 with a wide flow path width to be equal. Thus, the flow rate of the refrigerant flowing in the first inter-fin flow path 16 with a narrow flow path width can be adjusted to be equal to the flow rate of the refrigerant flowing in the first inter-fin flow path 16 with a wide flow path width.

[0084] Next, refer to Figure 1 , Fig. 9 and Fig.15 , a semiconductor module 1 according to a fourth modification of the first embodiment will be described. Fig.15 1 is a top view of the first flow path forming plate 32 of the semiconductor module 1 according to the fourth modification of the first embodiment. In the fourth modification, the same reference numerals are given to the parts that are repeated in the first embodiment, and the description thereof is omitted. The fourth modification is different from the first embodiment in that the width of the first partition wall 12 is narrower than the width of the first fin 13.

[0085] The width of the first partition wall 12 is narrower than the width of the first fin 13. As described above, if the refrigerant Figure 1 The first opening 8 shown in FIG. 1 flows into the heat sink 3, and then Fig. 9 As shown, the refrigerant collides with the second surface 31b of the heat transfer plate 31, and a vortex 23 is generated near the joint 22 between the first partition wall 12 and the heat transfer plate 31. If such a vortex 23 is generated, the heat exchange efficiency of the first partition wall 12 may be lower than that of the first fin 13, and the cooling effect on the center of the semiconductor element 2 is reduced. Therefore, in this modification, Fig.15 As shown in FIG. 1 , by making the width of the first partition wall 12 narrower than the width of the first fin 13, it is possible to Fig. 9 The second surface 31b of the heat transfer plate 31 shown is close to the center of the semiconductor element 2 and can increase the contact area of ​​the refrigerant with the second surface 31b of the heat transfer plate 31. Therefore, even when the vortex 23 is generated, the cooling effect on the center of the semiconductor element 2 is high.

[0086] Next, refer to Fig.12 , Fig.13 and Fig.16 , a semiconductor module 1 according to a fifth modification of the first embodiment will be described. Fig.16 1 is a top view of the first flow path forming plate 32 of the semiconductor module 1 according to the fifth modification of the first embodiment. In the fifth modification, the same reference numerals are given to the parts that are repeated in the first embodiment, and the description thereof is omitted. The fifth modification is different from the first embodiment in that the width of the first partition wall 12 is wider than the width of the first fin 13.

[0087] The width of the first partition wall 12 is wider than the width of the first fin 13. Fig.12 The second opening 9 shown in FIG. 1 flows into the heat sink 3, and then Fig.13 As shown, the refrigerant collides with the first partition wall 12. In this way, when the refrigerant collides with the first partition wall 12, the heat exchange efficiency of the first partition wall 12 is higher than the heat exchange efficiency of the first fin 13, and sometimes corrosion occurs in the first partition wall 12 due to the collision of the refrigerant. Therefore, in this modification, Fig.16 As shown, by making the width of the first partition wall 12 wider than the width of the first fin 13 , the heat dissipation area of ​​the first partition wall 12 can be increased, the cooling effect on the center of the semiconductor element 2 is enhanced, and the life of the first partition wall 12 is extended.

[0088] Next, refer to Figure 1 , Fig.17 and Fig.18 , a semiconductor module 1 according to a sixth modification of the first embodiment will be described. Fig.17It is a plan view showing the first partition wall 12 and the first fin 13 of the semiconductor module 1 according to the sixth modification of the first embodiment. Fig.18 1 is a top view showing the second partition wall 17 and the second fin 18 of the semiconductor module 1 according to the sixth variation of the first embodiment. In the sixth variation, the same reference numerals are given to the parts repeated in the first embodiment, and the description thereof is omitted. The sixth variation is different from the first embodiment in that the flow path width of the second inter-fin flow path 21 is wider than the flow path width of the first inter-fin flow path 16, and the width of the second fin 18 is wider than the width of the first fin 13.

[0089] Fig.18 The width of the second inter-fin flow path 21 is shown as Fig.17 The first inter-fin flow passage 16 shown has a wide flow passage width. In other words, the arrangement interval of the second fins 18 is wider than the arrangement interval of the first fins 13 . Fig.18 The width of the second fin 18 is shown as Fig.17 The first fin 13 shown has a wide width.

[0090] like Figure 1 As shown in FIG. 1 , since the second inter-fin flow path 21 is disposed at a position farther from the semiconductor element 2 than the first inter-fin flow path 16, it does not contribute to the cooling of the semiconductor element 2 compared to the first inter-fin flow path 16. On the other hand, the narrower the flow path width of the second inter-fin flow path 21 is, the greater the pressure loss of the refrigerant in the second inter-fin flow path 21. Therefore, in this modification, as shown in FIG. Fig.17 and Fig.18 As shown, by making the flow passage width of the second inter-fin flow passage 21 wider than the flow passage width of the first inter-fin flow passage 16 , the pressure loss of the refrigerant in the second inter-fin flow passage 21 can be reduced.

[0091] Here, the effects of this modification are further described. Figure 1 An insulating material that isolates electrical conduction is arranged between the semiconductor element 2 and the heat-conducting plate 31 shown, so that the semiconductor element 2 and the heat-conducting plate 31 are insulated. The material of the heat-conducting plate 31 is, for example, copper. On the other hand, the material of the insulating material is, for example, aluminum nitride or silicon carbide. Since the heat-conducting plate 31 and the insulating material are formed of different types of materials, the thermal expansion coefficients of the heat-conducting plate 31 and the insulating material are different. Therefore, when the heat-conducting plate 31 and the insulating material are joined, the heat-conducting plate 31 and the insulating material are heated up, and then, if the heat-conducting plate 31 and the insulating material are cooled, warping occurs in the heat-conducting plate 31. If warping occurs in the heat-conducting plate 31, warping also occurs in the other plates 32 to 35, and warping occurs in the heat sink 3 as a whole.

[0092] As a method for reducing the warpage of such a heat sink 3, the following method can be considered, that is, not only the insulating material is bonded to the heat conduction plate 31, but also the insulating material is bonded to the bottom plate 35, and the heat conduction plate 31 and the bottom plate 35 are set to be substantially the same structure. In addition, as a method for reducing the warpage of the heat sink 3, a method can be considered to set the first flow path forming plate 32 and the second flow path forming plate 34 to be substantially the same structure. In the above-mentioned embodiment 1, the latter method is adopted, and the structure of the first fin 13 of the first flow path forming plate 32 and the structure of the second fin 18 of the second flow path forming plate 34 are set to be the same. That is, the setting interval of the first fin 13 and the setting interval of the second fin 18 are made the same, and the width of the first fin 13 and the width of the second fin 18 are made the same.

[0093] On the other hand, Fig.17 and Fig.18 As in the present modification shown in FIG. 1 , if the arrangement interval of the second fins 18 is set wider than the arrangement interval of the first fins 13 with an emphasis on reducing the pressure loss of the refrigerant in the second inter-fin flow path 21, the warping of the radiator 3 cannot be reduced. In this regard, in the present modification, by setting the width of the second fins 18 wider than the width of the first fins 13, the rigidity of the second fins 18 can be increased, and the warping of the radiator 3 can be suppressed. That is, in the present modification, by making the flow path width of the second inter-fin flow path 21 wider than the flow path width of the first inter-fin flow path 16, the pressure loss of the refrigerant in the second inter-fin flow path 21 can be reduced, and by making the width of the second fins 18 wider than the width of the first fins 13, the warping of the radiator 3 can be suppressed. In addition, not only the width of the second fins 18 but also the width of the first fins 13 can be set wider to reduce the warping of the radiator 3. Alternatively, the warping of the heat sink 3 may be reduced by simply increasing the width of the first fins 13 .

[0094] Implementation Method 2

[0095] Next, refer to Fig.19 , a semiconductor module 1A according to a second embodiment of the present invention will be described. Fig.19 1 is a diagram showing a semiconductor module 1A according to a second embodiment of the present invention, and is a plan view showing a state where the first partition wall 12, the first fin 13, and the relay channel 7 are projected onto the first surface 31a. Fig.19 In order to facilitate the description, the first partition wall 12 and the first fin 13 are shown by solid lines, and the relay flow path 7 and the semiconductor element 2 are shown by dotted lines. Fig.19 In the figure, the heat transfer plate 31 is depicted as being extremely small for ease of description. In the second embodiment, the same reference numerals are given to portions that overlap with those in the first embodiment, and description thereof is omitted. The second embodiment is different from the first embodiment in that six first divided regions 51 are provided.

[0096] In the present embodiment, a portion of the first flow path 5 is divided into six first divided areas 51 by six first partition walls 12. The six first partition walls 12 extend radially from one center point. The six first partition walls 12 are arranged at intervals of 60 degrees along the circumferential direction with one center point as the axis. When the six first partition walls 12 are distinguished, they are referred to as first partition walls 12e, 12f, 12g, 12h, 12i, and 12j. When the six first divided areas 51 are distinguished, they are referred to as first divided areas 51e, 51f, 51g, 51h, 51i, and 51j. Although not shown in the figure, a portion of the second flow path 6 is also divided into six second divided areas 61 by six second partition walls 17.

[0097] Six relay flow paths 7 are arranged at 60-degree intervals along the circumferential direction with one center point as the axis. When distinguishing the six relay flow paths 7, they are referred to as relay flow paths 7e, 7f, 7g, 7h, 7i, and 7j. When viewed from above, the first division area 51e and the relay flow path 7e are arranged at positions that overlap with each other. When viewed from above, the first division area 51f and the relay flow path 7f are arranged at positions that overlap with each other. When viewed from above, the first division area 51g and the relay flow path 7g are arranged at positions that overlap with each other. When viewed from above, the first division area 51h and the relay flow path 7h are arranged at positions that overlap with each other. When viewed from above, the first division area 51i and the relay flow path 7i are arranged at positions that overlap with each other. When viewed from above, the first division area 51j and the relay flow path 7j are arranged at positions that overlap with each other.

[0098] The positions when a portion of the first partition wall 12, a portion of the first fin 13, and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a overlap with the semiconductor element 2. In the present embodiment, the center points of the six first partition walls 12 are aligned with the center of the semiconductor element 2. The positions when a portion of the first partition wall 12 is projected onto the first surface 31a overlap with the center of the semiconductor element 2 and the periphery of the center of the semiconductor element 2. The positions when a portion of the first fin 13 and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a overlap with the periphery of the center of the semiconductor element 2. In addition, in the present embodiment, the positions when a portion of the first partition wall 12 is projected onto the first surface 31a overlap with the center of the semiconductor element 2, but the positions when a portion of the first fin 13 is projected onto the first surface 31a may also overlap with the center of the semiconductor element 2.

[0099] If the relay flow path 7, the first division area 51, and the first fin 13 are projected onto the first surface 31a, the relay flow path 7 is disposed one at each position overlapping with each of the plurality of first division areas 51, and the relay flow path 7 is formed elongated in a manner to cross the plurality of first fins 13. The length direction of the relay flow path 7 is orthogonal to the length direction of the first fin 13. The relay flow path 7 is disposed at a position overlapping with a root portion of the first fin 13 connected to the first partition wall 12.

[0100] In the present embodiment, a portion of the first flow path 5 is divided into six first divided areas 51 by six first partition walls 12. In addition, if the relay flow path 7, the first divided areas 51, and the first fins 13 are projected onto the first surface 31a, one relay flow path 7 is disposed at each position overlapping with each of the plurality of first divided areas 51. Therefore, the refrigerant flows from the relay flow path 7 into the first divided areas 51, and the refrigerant collides with the second surface 31b of the heat transfer plate 31 in each of the first divided areas 51. As a result, compared with the heat sink 3 according to the first embodiment in which four first divided areas 51 are provided, the number of locations where the refrigerant collides with the second surface 31b of the heat transfer plate 31 increases, and the cooling effect on the center of the semiconductor element 2 becomes higher. Furthermore, in the present embodiment, the lengths of the first fins 13 in each first divided region 51 are made substantially the same in order to make the pressure loss of the refrigerant in the first inter-fin flow path 16 substantially equal. However, the lengths of the first fins 13 in each first divided region 51 may be made different.

[0101] Implementation 3

[0102] Next, refer to Figure 20 to Figure 23 , a semiconductor module 1B according to a third embodiment of the present invention will be described. Fig. 20 It is an exploded perspective view showing a semiconductor module 1B according to a third embodiment of the present invention. Fig.21 1 is a plan view showing a first flow channel forming plate 32 of a semiconductor module 1B according to the third embodiment. Fig. 22 is along Fig.21 FIG. 1 is a cross-sectional view of the semiconductor module 1B taken along line XXII-XXII. Fig.23 is along Fig.21 A cross-sectional view of the semiconductor module 1B taken along line XXIII-XXIII is shown. Fig.21 In FIG. 1 , for convenience of explanation, the semiconductor element 2 and the relay flow path 7 are shown by dotted lines. Fig.21 For convenience of explanation, only the first flow path forming plate 32 in the radiator 3 is shown. Fig. 22 and Fig.23In the third embodiment, the same reference numerals are given to the parts repeated in the first embodiment, and the description thereof is omitted. The third embodiment is different from the first embodiment in that the bottom plate 35 is provided with the first opening 8 and the second opening 9, the second flow path forming plate 34 is provided with the third opening 10, and two first divided areas 51 are provided.

[0103] like Fig. 20 As shown, the heat sink 3 is formed in a manner that a heat conduction plate 31, a first flow path forming plate 32, a relay flow path forming plate 33, a second flow path forming plate 34 and a bottom plate 35 are overlapped. From the side close to the semiconductor element 2, the heat conduction plate 31, the first flow path forming plate 32, the relay flow path forming plate 33, the second flow path forming plate 34 and the bottom plate 35 are arranged in sequence. The heat conduction plate 31 is a flat plate without an opening. The first opening 8 and the second opening 9 are formed in the bottom plate 35 in this embodiment. The first opening 8 and the second opening 9 are arranged at positions away from each other. The first opening 8 and the second opening 9 penetrate the bottom plate 35 in the plate thickness direction of the bottom plate 35. One of the first opening 8 and the second opening 9 is a refrigerant inlet. The other of the first opening 8 and the second opening 9 is a refrigerant outlet.

[0104] The third opening 10 is formed in the second flow path forming plate 34 in the present embodiment. The third opening 10 penetrates the second flow path forming plate 34 in the plate thickness direction of the second flow path forming plate 34. A second partition wall 19e is provided around the third opening 10. The third opening 10 is separated from the second partition area 61 and the second common head area 62 by the second partition wall 19e. As a result, the refrigerant flowing in the third opening 10 does not intersect with the refrigerant flowing in the second partition area 61 and the second common head area 62. When viewed from above, the first opening 8, the third opening 10, the fourth opening 11 and the first common head area 52 are arranged at positions overlapping each other. The first opening 8, the third opening 10, the fourth opening 11 and the first common head area 52 are connected to each other.

[0105] like Fig.21 As shown, in this embodiment, a portion of the first flow path 5 is divided into two first divided areas 51 by one first partition wall 12. One first partition wall 12 is arranged along Fig.21The first partition wall 12 protrudes inward from one side of the first peripheral wall 15 of the square ring shape. The front end of the first partition wall 12 is connected to the first partition wall 14e of the rectangular shape. One of the two spaces separated by the first partition wall 12, one side of the first peripheral wall 15 and the first partition wall 14e is the first partition area 51k. The other of the two spaces separated by the first partition wall 12, one side of the first peripheral wall 15 and the first partition wall 14e is the first partition area 51m.

[0106] A plurality of first fins 13 are arranged in each first division area 51. The plurality of first fins 13 are arranged in parallel with intervals therebetween. The first fins 13 in all first division areas 51 are arranged at equal intervals. The first fins 13 protrude from the first partition wall 12 toward the first division area 51. One end of the first fin 13 along the length direction is connected to the first partition wall 12. The other end of the first fin 13 along the length direction faces the first common header area 52. The first fins 13 arranged in adjacent first division areas 51 protrude from the same first partition wall 12 in opposite directions. The first fins 13 protrude from one end face of the first partition wall 12 along the width direction and the other end face of the first partition wall 12 along the width direction, respectively. The first inter-fin flow paths 16 are formed between the adjacent first fins 13 and the first fins 13 , between the adjacent first fins 13 and one side of the first outer peripheral wall 15 , and between the adjacent first fins 13 and the first partition walls 14 e .

[0107] like Fig. 20 As shown, in this embodiment, a portion of the second flow path 6 is divided into two second divided areas 61 by one second partition wall 17. One second partition wall 17 is arranged along Fig. 20 The second common end cover area 62 extends linearly in the left-right direction of the paper surface. When the two second divided areas 61 are distinguished, they are referred to as second divided areas 61k and 61m. When viewed from above, the second common end cover area 62 is arranged at a position overlapping with the second opening 9. The second common end cover area 62 is connected to the second opening 9.

[0108] The second partition wall 17 protrudes inward from one side of the square ring-shaped second outer peripheral wall 20. The front end of the second partition wall 17 is connected to the rectangular second partition wall 19e. One of the two spaces separated by the second partition wall 17, one side of the second outer peripheral wall 20 and the second partition wall 19e is the second divided area 61k. The other of the two spaces separated by the second partition wall 17, one side of the second outer peripheral wall 20 and the second partition wall 19e is the second divided area 61m.

[0109] A plurality of second fins 18 are arranged in each second division area 61. The plurality of second fins 18 are arranged in parallel with each other at intervals. The second fins 18 in all second division areas 61 are arranged at equal intervals. The second fins 18 protrude from the second partition wall 17 toward the second division area 61. One end of the second fin 18 along the length direction is connected to the second partition wall 17. The other end of the second fin 18 along the length direction faces the second common head area 62. The second fins 18 arranged in adjacent second division areas 61 protrude from the same second partition wall 17 in opposite directions. The second fins 18 protrude from one end face of the second partition wall 17 along the width direction and the other end face of the second partition wall 17 along the width direction, respectively. A second inter-fin flow path 21 is formed between adjacent second fins 18 and second fins 18, between adjacent second fins 18 and one side of the second peripheral wall 20, and between adjacent second fins 18 and the second partition wall 19e. The length direction of the first fin 13 in the first divided area 51k is parallel to the length direction of the second fin 18 in the second divided area 61k. The length direction of the first fin 13 in the first divided area 51m is parallel to the length direction of the second fin 18 in the second divided area 61m.

[0110] like Fig. 22 As shown, the first fin 13 is provided to contact the second surface 31b of the heat transfer plate 31 and the third surface 33a of the relay flow path forming plate 33. The second fin 18 is provided to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35.

[0111] like Fig.23 As shown, the first partition wall 12 is arranged to contact the second surface 31b of the heat transfer plate 31 and the third surface 33a of the relay flow path forming plate 33. The first peripheral wall 15 is arranged to contact the second surface 31b of the heat transfer plate 31 and the third surface 33a of the relay flow path forming plate 33. The second partition wall 17 is arranged to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35. The second peripheral wall 20 is arranged to contact the fourth surface 33b of the relay flow path forming plate 33 and the bottom plate 35. The first inter-fin flow path 16 and the second inter-fin flow path 21 are connected via the relay flow path 7. The width of the first partition wall 12 is the same as the width of the second partition wall 17. The width of the first fin 13 is the same as the width of the second fin 18. The setting interval of the first fin 13 is the same as the setting interval of the second fin 18.

[0112] like Fig. 20As shown, two relay flow paths 7 are arranged at positions away from each other. When the two relay flow paths 7 are distinguished, they are referred to as relay flow paths 7k and 7m. When viewed from above, the first segmented area 51k, the second segmented area 61k, and the relay flow path 7k are arranged at positions overlapping each other. When viewed from above, the first segmented area 51m, the second segmented area 61m, and the relay flow path 7m are arranged at positions overlapping each other.

[0113] like Fig.21 As shown, the position when a portion of the first partition wall 12, a portion of the first fin 13, and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a (not shown) overlaps with the semiconductor element 2. In the present embodiment, the center point of the first partition wall 12 is aligned with the center of the semiconductor element 2. The position when a portion of the first partition wall 12 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2 and the periphery of the center of the semiconductor element 2. The position when a portion of the first fin 13 and a portion of the first inter-fin flow path 16 are projected onto the first surface 31a overlaps with the periphery of the center of the semiconductor element 2. In addition, in the present embodiment, the position when a portion of the first partition wall 12 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2, but it is also possible that the position when a portion of the first fin 13 is projected onto the first surface 31a overlaps with the center of the semiconductor element 2.

[0114] If the relay flow path 7, the first division area 51, and the first fin 13 are projected onto the first surface 31a, the relay flow path 7 is disposed one at each position overlapping with each of the plurality of first division areas 51, and the relay flow path 7 is formed elongated in a manner to cross the plurality of first fins 13. The length direction of the relay flow path 7 is orthogonal to the length direction of the first fin 13. The relay flow path 7 is disposed at a position overlapping with a root portion of the first fin 13 connected to the first partition wall 12.

[0115] Next, refer to Fig. 20, the flow direction of the refrigerant is described. First, the situation where the refrigerant flows in from the first opening 8 is described. The refrigerant flowing into the radiator 3 from the first opening 8 flows into the first common head area 52 through the third opening 10 and the fourth opening 11. Next, the refrigerant flows from the first common head area 52 into the first inter-fin flow path 16 in each first divided area 51. Next, the refrigerant flows from the first inter-fin flow path 16 through the relay flow path 7 into the second inter-fin flow path 21 in each second divided area 61. At this time, the refrigerant in the first inter-fin flow path 16 in the first divided area 51k flows into the second inter-fin flow path 21 in the second divided area 61k through the relay flow path 7k. The refrigerant in the first inter-fin flow path 16 in the first divided area 51m flows into the second inter-fin flow path 21 in the second divided area 61m through the relay flow path 7m. Thereafter, the refrigerant flows from the second inter-fin flow paths 21 in each second divided region 61 into the second common end region 62. Next, the refrigerant flows out from the second common end region 62 through the second opening 9 to the outside of the heat sink 3.

[0116] Next, the case where the refrigerant flows in from the second opening 9 is described. The refrigerant flowing into the radiator 3 from the second opening 9 flows into the second common end region 62. Next, the refrigerant flows from the second common end region 62 into the second inter-fin flow path 21 in each second divided region 61. Next, the refrigerant flows from the second inter-fin flow path 21 through the relay flow path 7 into the first inter-fin flow path 16 in each first divided region 51. At this time, the refrigerant in the second inter-fin flow path 21 in the second divided region 61k flows into the first inter-fin flow path 16 in the first divided region 51k through the relay flow path 7k. The refrigerant in the second inter-fin flow path 21 in the second divided region 61m flows into the first inter-fin flow path 16 in the first divided region 51m through the relay flow path 7m. Thereafter, the refrigerant flows from the first inter-fin flow path 16 in each first divided region 51 into the first common end region 52. Next, the refrigerant flows out from the first common head region 52 to the outside of the radiator 3 through the fourth opening 11 , the third opening 10 , and the first opening 8 .

[0117] In the present embodiment, a portion of the first flow path 5 is divided into two first divided areas 51 by a first partition wall 12. In addition, a portion of the second flow path 6 is divided into two second divided areas 61 by a second partition wall 17. In addition, two relay flow paths 7 are formed on the relay flow path forming plate 33. Therefore, compared with the heat sink 3 according to the first embodiment in which four first divided areas 51, four second divided areas 61 and four relay flow paths 7 are formed, the structures of the first flow path 5, the second flow path 6 and the relay flow path 7 become simple, and the manufacturing cost of the heat sink 3 can be reduced.

[0118] In addition, the first opening 8 and the second opening 9 may be provided on the heat conducting plate 31 or the bottom plate 35 according to the use conditions of the heat sink 3. In the present embodiment, the number of plates forming the heat sink 3 is set to 5, but the number of plates forming the heat sink 3 may be greater than or equal to 6. In the present embodiment, the heat sink 3 is formed by a plurality of plates 31 to 35, but the heat sink 3 may be formed integrally using a 3D printer or the like.

[0119] The structure shown in the above embodiment is an example of the content of the present invention, and may be combined with other well-known technologies, or part of the structure may be omitted or changed within the scope not departing from the gist of the present invention.

[0120] Description of the label

[0121] 1, 1A, 1B semiconductor module, 2 semiconductor element, 3 heat sink, 4 refrigerant flow path, 5 first flow path, 6 second flow path, 7, 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j, 7k, 7m relay flow path, 7A center side relay flow path, 7B peripheral side relay flow path, 8 first opening, 9 second opening, 10 third opening, 11 fourth opening, 12, 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j first partition wall, 13 first fin, 14a, 14b, 14c, 14e first partition wall, 15 first peripheral wall, 16 first inter-fin flow path, 16A center side inter-fin flow path, 16B peripheral side inter-fin flow path, 17, 17a, 17b , 17c, 17d second partition wall, 18 second fin, 19a, 19b, 19c, 19e second partition wall, 20 second peripheral wall, 21 second inter-fin flow path, 22 joint, 23 vortex, 24 center partition wall, 31 heat transfer plate, 31a first surface, 31b second surface, 32 first flow path forming plate, 33 relay flow path forming plate, 33a third surface, 33b first 4 sides, 34 second flow path forming plate, 35 bottom plate, 51, 51a, 51b, 51c, 51d, 51e, 51f, 51g, 51h, 51i, 51j, 51k, 51m first divided area, 52 first common head area, 61, 61a, 61b, 61c, 61d, 61k, 61m second divided area, 62 second common head area.

Claims

1. A radiator having a refrigerant flow path formed therein for allowing a refrigerant to flow for cooling a cooling object, The radiator is characterized by having: A first component having a first surface on which the cooling object is arranged and a second surface which is the back side of the first surface; a second member having a third surface facing the second surface and a fourth surface which is the back side of the third surface; a first partition wall provided so as to be in contact with the second surface of the first member and the third surface of the second member; and a plurality of first fins arranged to contact the second surface of the first member, The refrigerant flow path includes a first flow path formed between the first component and the second component. forming a plurality of first divided regions separated by the first partition wall in the first flow path, In the first divided region, the plurality of first fins are arranged in a manner spaced apart from each other. The first fins protrude from each of the first partition walls toward the first division region, A position when at least a portion of the first partition wall is projected onto the first surface overlaps with a center portion of the cooling target.

2. The heat sink according to claim 1, characterized in that: It also has a third component, which is arranged opposite to the first component in a manner of sandwiching the second component. The refrigerant flow path comprises: a second flow path formed between the second member and the third member; and A plurality of relay flow paths are formed in the second member and connect the first flow path and the second flow path.

3. The heat sink according to claim 2, characterized in that: When the relay flow path, the first division region, and the first fin are projected onto the first surface, at least one relay flow path is disposed at a position overlapping with each of the plurality of first division regions, and the relay flow path is elongated to cross the plurality of first fins.

4. The heat sink according to claim 2, characterized in that: The first partition wall is a plurality of walls extending radially, The first fins arranged in the adjacent first division regions protrude from the first partition walls different from each other.

5. The heat sink according to claim 3, characterized in that: The first partition wall is a plurality of walls extending radially, The first fins arranged in the adjacent first division regions protrude from the first partition walls different from each other.

6. The heat sink according to claim 4, characterized in that: The relay flow path is arranged at a position overlapping with a root portion of the first fin connected to the first partition wall.

7. The heat sink according to claim 5, characterized in that: The relay flow path is arranged at a position overlapping with a root portion of the first fin connected to the first partition wall.

8. The heat sink according to claim 1, characterized in that There are a plurality of the first partition walls, One ends of the plurality of first partition walls are connected to each other.

9. The heat sink according to claim 1, characterized in that: There are a plurality of the first partition walls, The connection point where the ends of the plurality of first partition walls are connected to each other overlaps with the periphery of the center portion of the cooling object, The plurality of first partition walls extend from the connection point in different directions.

10. The radiator according to any one of claims 1 to 9, characterized in that: A position where at least a portion of the first fin is projected onto the first surface overlaps with a center portion of the cooling target.

11. The radiator according to any one of claims 1 to 9, characterized in that: A first inter-fin flow path through which the refrigerant flows is formed between adjacent first fins, A first end region is formed in the first flow path so as to surround the plurality of first divided regions. The first end region communicates with the first inter-fin flow paths in each of the first divided regions.

12. The radiator according to any one of claims 1 to 9, characterized in that: Four first divided regions are formed in the first flow channel.

13. The radiator according to any one of claims 1 to 9, characterized in that: The first fins in the first divided region are arranged at uneven intervals.

14. The radiator according to any one of claims 1 to 9, characterized in that: The width of the first partition wall is narrower than the width of the first fin.

15. The radiator according to any one of claims 2 to 7, characterized in that: have: a second partition wall provided so as to be in contact with the fourth surface of the second member and the third member; and a plurality of second fins arranged to contact the fourth surface of the second component and the third component, forming a plurality of second divided regions separated by the second partition wall in the second flow path, In the second divided region, the plurality of second fins are arranged in a manner spaced apart from each other. The arrangement interval of the second fins is wider than the arrangement interval of the first fins.

16. The heat sink according to claim 15, characterized in that The second fin has a width greater than that of the first fin.

17. A radiator having a refrigerant flow path formed therein for allowing a refrigerant for cooling a cooling object to flow, The radiator is characterized in that The refrigerant flow path is formed in a hierarchical manner to include a first flow path, a second flow path, and a relay flow path. The first flow path is closest to the first surface where the cooling object is arranged. The second flow path is formed away from the first surface more than the first flow path in the normal direction of the first surface. The relay channel is located between the first channel and the second channel and connects the first channel and the second channel. The first flow channel has, as inner surfaces, a second surface on the first surface side and a third surface opposite to the second surface. forming a plurality of first divided regions separated by first partition walls provided between the second surface and the third surface in the first flow path, The first division region has a plurality of first fins arranged at intervals from each other and formed so as to extend from the first partition wall. The position of at least a portion of the first partition wall when projected onto the first surface overlaps with the center of the region of the first surface where the cooling target is disposed. If the relay flow path, the first division area, and the first fin are projected onto the first surface, at least one relay flow path is disposed at each position overlapping with each of the plurality of first division areas, and the relay flow path is formed in an elongated manner to cross the plurality of first fins along the first partition wall. The refrigerant flows between the first flow path and the second flow path via the relay flow path.

18. The heat sink according to claim 17, characterized in that A position when at least a portion of the first fin is projected onto the first surface overlaps with a center portion of a region of the first surface where the cooling target is provided.

19. A semiconductor module, characterized in that: have: The radiator according to any one of claims 1 to 18; and The semiconductor element to be cooled is arranged on the first surface.

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