Cooling device

Abstract

This cooling device includes: a heat sink having a flat plate part and a fin protruding from the flat plate part in an intersecting direction intersecting a plate surface; a first member having a flat plate shape and formed with an opening for housing at least the flat plate part of the heat sink or a part of the fin; a second member having a flat plate shape and closing the opening of the first member; and a third member for, together with the first member and the second member, housing the heat sink and forming a space through which a refrigerant flows.

Description

Cooling device

[0001] The present invention relates to a cooling device.

[0002] For example, the power semiconductor module described in Patent Document 1 is configured as follows. The power semiconductor module includes: a metal base plate having a first surface and a second surface; a laminated substrate bonded to the first surface and having a third surface and a fourth surface; a semiconductor element mounted on the third surface; a resin case disposed on the first surface side of the metal base plate and surrounding the laminated substrate and the semiconductor element; and a cooling case bonded to the second surface side of the metal base plate and formed with a space through which a cooling liquid can flow. The cooling case has an inlet portion and an outlet portion for the cooling liquid, a first flange is provided on an introduction port side of the inlet portion, a second flange is provided on a discharge port side of the outlet portion, a main surface of the first flange is parallel to the first surface of the metal base plate, and a main surface of the second flange is parallel to the first surface of the metal base plate. Further, the cooling case bonded to the back surface of the metal base plate has a bottom wall and a side wall formed around the bottom wall, and an upper end side thereof is open. By joining the upper end of the cooling case to the metal base plate by, for example, brazing, an internal space surrounded by the metal base plate and the cooling case is formed. Fins serving as a heat sink are disposed in this internal space. A cooling body for a semiconductor chip is constituted by the metal base plate, the cooling case, and the fins. Further, the cooling device described in Patent Document 2 includes a top plate, a side wall annularly connected to a back surface of the top plate, and a cooling bottom plate facing the top plate and connected to a back surface of the side wall. The top plate has a rectangular shape surrounded on four sides by long sides and short sides in a plan view, and fastening holes are respectively formed at four corners of the top plate.

[0003] Japanese Patent No. 6569781, Japanese Unexamined Patent Publication No. 2023-103785

[0004] In recent years, along with the miniaturization of drive units mounted in vehicles and the like, there has been a strong demand for miniaturization of power control units. Therefore, cooling devices that cool semiconductor elements such as power semiconductors are required to be compact while maintaining heat dissipation performance and water flow resistance. An object of the present invention is to provide a cooling device that can achieve miniaturization.

[0005] The present invention, completed with this objective in mind, is a cooling device comprising: a heat sink having fins; a first member which is flat and has an opening formed to accommodate at least a part of the fins; a second member which is flat and closes the opening of the first member; and a third member which, together with the first member and the second member, accommodates the heat sink and forms a space through which a refrigerant flows. Here, the first member may have an inlet for refrigerant to flow into the space and an outlet for liquid to flow out of the space. The third member may also have an inlet for refrigerant to flow into the space and an outlet for liquid to flow out of the space. The first member may also have a through hole through which the shaft portion of a fastening member can pass. The first member may also have a positioning portion for determining the position of the heat sink. The second member may be joined to one side of the first member, and the third member may be joined to the other side of the first member. Furthermore, the first member may have a recess formed around the opening, which is recessed from one side of the first member, and the second member may be fitted into the recess.

[0006] According to the present invention, it is possible to provide a cooling device that can be miniaturized.

[0007] This figure shows an example of the external appearance of a cooling device according to the first embodiment. This is an example of a diagram showing the components of a semiconductor device according to the first embodiment disassembled. This figure shows an example of a cross-section of a semiconductor device according to the first embodiment. This figure shows an example of the external appearance of a cooling device according to the second embodiment. This is an example of a diagram showing the components of a semiconductor device according to the second embodiment disassembled. This figure shows an example of a cross-section of a semiconductor device according to the second embodiment. This figure shows an example of a modified example of the third member.

[0008] The embodiments will be described in detail below with reference to the attached drawings. <First Embodiment> Figure 1 is a diagram showing an example of the external appearance of the cooling device 2 according to the first embodiment. Figure 1(a) is an example of a view of the cooling device 2 from diagonally above, and Figure 1(b) is an example of a view of the cooling device 2 from diagonally below. Figure 2 is an example of an exploded view of the components constituting the semiconductor device 1 according to the first embodiment. Figure 3 is a diagram showing an example of a cross-section of the semiconductor device 1 according to the first embodiment. Figure 3 is a cross-sectional view of section III-III in Figure 1.

[0009] The semiconductor device 1 according to the first embodiment comprises a semiconductor module 100 having semiconductor elements 102 and a cooling device 2 for cooling the semiconductor module 100. The semiconductor device 1 has a plurality of semiconductor modules 100 (three in Figure 2) placed on the cooling device 2. Hereinafter, the direction in which the semiconductor modules 100 and the cooling device 2 are stacked may be simply referred to as the "up and down direction". Also, in the rectangular cooling device 2, the rectangular longitudinal direction perpendicular to the up and down direction may be simply referred to as the "longitudinal direction", and the rectangular short direction may be simply referred to as the "short direction".

[0010] (Semiconductor Module 100) As shown in Figure 3, the semiconductor module 100 is a card-type power module having an insulating substrate 101, a semiconductor element 102, a lead frame 103, and a sealing resin portion 104 that covers at least the insulating substrate 101 and the semiconductor element 102. The insulating substrate 101 is an insulating heat dissipation circuit board in which copper plates are bonded and integrated on both sides of a ceramic plate, which is an insulating material. Examples of bonding between the ceramic plate and the copper plate include direct copper bonding and active metal brazing.

[0011] The semiconductor element 102 can be exemplified as a power semiconductor element such as a transistor, thyristor, or diode used for power control. The insulating substrate 101 and the semiconductor element 102, and the semiconductor element 102 and the lead frame 103 can be exemplified as being joined by solder or sintered metal (e.g., silver, copper). The sealing resin portion 104 is molded using a thermosetting resin with a curing temperature of, for example, 200°C or higher. The thermosetting resin can be exemplified as an insulating resin such as epoxy resin or silicone resin.

[0012] (Cooling device 2) The cooling device 2 comprises a plurality of heat sinks 5 (the same number as the semiconductor modules 100; three in Figure 2), a flat plate-shaped first member 10 having an opening 11 that accommodates a part of the heat sinks 5, and a flat plate-shaped second member 20 that closes the opening 11 of the first member 10. The cooling device 2 also comprises a third member 30 together with the first member 10 and the second member 20 that accommodates the heat sinks 5 and forms a space S through which cooling water, as an example of a refrigerant, flows.

[0013] (Heat sink 5) The heat sink 5 has a flat plate-shaped portion 51 and a plurality of fins 52 that protrude from the flat plate-shaped portion 51 in a direction perpendicular to the plate surface. The flat plate-shaped portion 51 has a fin side surface 511, which is the side on which the fins 52 are formed, and a flat surface 512, which is the side on which the fins 52 are not formed. The fins 52 can be exemplified as being flat plates parallel to the longitudinal direction. The fins 52 may also be flat and wavy, having portions that are inclined in the longitudinal direction. The fins 52 may also be columnar, with the direction of protrusion from the flat plate-shaped portion 51 being in the columnar direction. The shape obtained by cutting the fins 52 at a plane perpendicular to the protrusion direction (hereinafter sometimes referred to as the "cross-sectional shape") can be exemplified as a quadrilateral such as a square, rectangle, or rhombus. The cross-sectional shape may also be a circle or an ellipse.

[0014] The heat sink 5 can be exemplified as being formed by forging. Alternatively, the heat sink 5 can be exemplified as being formed by machining an object formed by, for example, extrusion molding. Furthermore, the heat sink 5 is formed from at least one of copper or aluminum.

[0015] (First Member 10) The first member 10 is both a flat plate and a rectangular parallelepiped. The first member 10 has an opening 11 in its center into which the flat plate portion 51 of the heat sink 5 is fitted. The first member 10 also has fastening holes 12 at each of its four corners for passing the shaft portion of a fastening member (e.g., a bolt) used to attach the semiconductor device 1 to another object. The first member 10 also has an inlet 13 at one end in the longitudinal direction for allowing cooling water to flow into the space S. The first member 10 also has an outlet 14 at the other end in the longitudinal direction for allowing cooling water to flow out of the space S. The opening 11, fastening holes 12, inlet 13 and outlet 14 are through holes that penetrate the first member 10 in the vertical direction.

[0016] Furthermore, the first member 10 has a recess 16 formed around the opening 11, recessed from the lower surface 15. The recess 16 is the part into which the flat plate-shaped second member 20 is fitted, and it can be exemplified that the depth of the recess 16 (in other words, its size in the vertical direction) is greater than or equal to the thickness of the second member 20. It can be exemplified that the size of the recess 16 in the direction parallel to the lower surface 15 is three times or more the depth of the recess 16.

[0017] Furthermore, the first member 10 has positioning parts 17 that determine the longitudinal positions of the multiple heat sinks 5 fitted into the opening 11. Multiple positioning parts 17 are provided at each of the short-side ends of the rectangular opening 11, dividing the longitudinal length equally (three equal parts in Figure 2) to the same number as the heat sinks 5 (four in Figure 2). The positioning parts 17 are provided so as to protrude into the opening 11 from the periphery surface 18 which is provided around the opening 11 and is parallel to the vertical direction. The size of each positioning part 17 in the short-side direction (in other words, the amount of protrusion from the periphery surface 18) can be exemplified as being 1 / 10 or less of the size of the opening 11 in the short-side direction. The positioning parts 17 only need to be large enough to suppress the longitudinal movement of the heat sinks 5 fitted into the opening 11, and reducing the size of the positioning parts 17 in the short-side direction reduces the water flow resistance of the cooling water in the space S.

[0018] The material of the first member 10 can be an aluminum material such as A3003 or A6063. For example, the first member 10 can be formed by pressing a sheet material rolled using A3003 to create an opening 11, a fastening hole 12, an inlet 13, an outlet 14, a recess 16, and a positioning portion 17. By forming the opening 11, fastening hole 12, inlet 13, outlet 14, and positioning portion 17 on the first member 10, the positional accuracy of each part can be improved. In addition, since the first member 10 can be formed by progressive press working, the cost of the first member 10 can be reduced.

[0019] (Second Member 20) The second member 20 is rectangular in shape, with its longitudinal dimensions being larger than the longitudinal dimensions of the opening 11 of the first member 10, and its transverse dimensions being larger than the transverse dimensions of the opening 11 of the first member 10. The second member 20 is joined to the first member 10 by being fitted into the recess 16 of the first member 10, and closes the lower part of the opening 11 of the first member 10. It can be exemplified that the second member 20 is formed from a clad material formed by rolling an aluminum alloy core material and a brazing material. It can also be exemplified that the second member 20 is joined to the first member 10 by brazing. It can also be exemplified that the second member 20 is formed by press working.

[0020] (Third Member 30) The third member 30 is concave and has a flat bottom portion 31, a side portion 32 extending from the outer circumference of the bottom portion 31 in a direction perpendicular to the bottom portion 31, and a flange 33 projecting outward from the tip of the side portion 32 in a direction parallel to the bottom portion 31. A recess is formed by the bottom portion 31 and the side portion 32, and the flange 33 is formed around this recess. The third member 30 is formed such that the opening 11, the inlet 13 and the outlet 14 are located inside the side portion 32 and the flange 33, and the fastening hole 12 is located outside the side portion 32 and the flange 33.

[0021] The third member 30 can be exemplified as being formed from a clad material formed by rolling an aluminum alloy core material and a brazing material. Furthermore, the third member 30 can be exemplified as being joined to the first member 10 by brazing with the flange 33 in contact with the upper surface 19 of the first member 10. The third member 30 can also be exemplified as being formed by press working. In addition, the third member 30 and the second member 20 may have the same plate thickness and be made of the same material.

[0022] The cooling device 2 configured as described above can be manufactured as follows. First, the second member 20 is fitted into the recess 16 of the first member 10, and a plurality of heat sinks 5 are fitted into the opening 11 of the first member 10. At this time, the flat surface 512 of the flat plate portion 51 of the heat sink 5 is positioned so that it contacts the second member 20, and at least a part of the flat plate portion 51 is housed within the opening 11. Furthermore, the heat sink 5 provided at one end in the longitudinal direction of the plurality of heat sinks 5 is positioned between the one end in the longitudinal direction of the peripheral surface 18 of the first member 10 and the positioning portion 17. Furthermore, the heat sink 5 provided at the other end in the longitudinal direction of the plurality of heat sinks 5 is positioned between the other end in the longitudinal direction of the peripheral surface 18 of the first member 10 and the positioning portion 17. Furthermore, the heat sinks 5 that are not provided at the longitudinal ends of the plurality of heat sinks 5 are positioned between the positioning portions 17. Next, the flange 33 of the third member 30 is placed on the upper surface 19 of the first member 10. Then, the first member 10 and the second member 20, the first member 10 and the third member 30, and the flat plate portion 51 of the heat sink 5 and the second member 20 are brazed together. In addition, the tip of the fin 52 of the heat sink 5 and the bottom portion 31 of the third member 30 are brazed together.

[0023] After manufacturing the cooling device 2, the semiconductor device 1 is manufactured by joining the copper plate of the insulating substrate 101 of the semiconductor module 100 to the third member 30 of the cooling device 2 using, for example, solder or sintered metal (for example, silver, copper). When soldering the copper plate of the insulating substrate 101 of the semiconductor module 100 to the third member 30, the third member 30 may be nickel-plated. Also, when silver-sintering the copper plate of the insulating substrate 101 of the semiconductor module 100 to the third member 30, the third member 30 may be silver-plated.

[0024] In the cooling device 2 for the semiconductor device 1 configured as described above, cooling water flows into the space S from the inlet 13 formed in the first member 10 and flows out from the outlet 14. In other words, the direction of flow of the cooling water is from the side where the inlet 13 is formed to the side where the outlet 14 is formed. The heat emitted from the semiconductor element 102 of the semiconductor module 100 is cooled by the cooling water flowing in the space S of the cooling device 2.

[0025] (Features of Cooling Device 2) The cooling device 2 comprises a heat sink 5 having a flat plate portion 51 and fins 52 protruding from the flat plate portion 51 in an upward and downward direction (an example of an intersecting direction) that intersects the plate surface, and a first member 10 having an opening 11 formed therein that accommodates at least a part of the flat plate portion 51 of the heat sink 5. The cooling device 2 also comprises a second member 20 which is flat and closes the opening 11 of the first member 10, and a third member 30 which, together with the first member 10 and the second member 20, accommodates the heat sink 5 and forms a space S through which cooling water (an example of a refrigerant) flows.

[0026] Here, we consider a cooling device according to a comparative example in which the opening of the third member 30 is covered with a cover, which is a flat plate-shaped member that differs in that an opening 11 is not formed in relation to the first member 10, and the heat sink 5 is housed between the third member 30 and the cover. In cooling device 2, since a part of the flat plate-shaped portion 51 of the heat sink 5 is housed in the opening 11 of the first member 10, the vertical size is smaller compared to the cooling device according to the comparative example in which the heat sink 5 is placed on top of the cover, even if the height of the fins 52 is the same. Therefore, with cooling device 2, miniaturization can be achieved even if the height of the fins 52 is the same, in other words, the heat dissipation performance is the same. Furthermore, with cooling device 2, since a part of the flat plate-shaped portion 51 of the heat sink 5 is housed in the opening 11 of the first member 10, the water flow resistance can be reduced compared to a configuration in which a part of the flat plate-shaped portion 51 is not housed in the opening 11.

[0027] Furthermore, the first member 10 has an inlet 13 for introducing cooling water into the space S and an outlet 14 for releasing cooling water from the space S. In other words, the inlet 13 and outlet 14 are not formed in the second member 20 and the third member 30. Since the vertical size of the cooling device 2 is determined by the heat sink 5, the second member 20, and the third member 30, increasing the thickness of the first member 10 does not affect the vertical size of the cooling device 2. Therefore, the thickness of the first member 10 can be increased without affecting the vertical size of the cooling device 2. By increasing the thickness of the first member 10, the rigidity around the inlet 13 and outlet 14 can be increased, thereby improving the sealing performance of the cooling water flowing through the inlet 13 and outlet 14. In other words, the sealing performance can be improved without affecting the vertical size of the cooling device 2. In addition, the inlet 13 and outlet 14 are located further outward in the longitudinal direction than the heat sink 5. Therefore, the magnitude of the direction perpendicular to the flow direction of the cooling water (for example, the short direction) in the cooling device 2 can be reduced.

[0028] Furthermore, the first member 10 has a fastening hole 12 (an example of a through hole) through which the shaft of a fastening member (e.g., a bolt) can pass. By increasing the thickness of the first member 10, the rigidity around the fastening hole 12 can be increased, so the fastening strength can be increased without affecting the vertical size of the cooling device 2. Also, since the fastening seat surface for fastening the cooling device 2 to another object and the sealing surfaces of the inlet 13 and outlet 14 are both the lower surface 15 of the first member 10, it is possible to prevent a step difference between the fastening seat surface and the sealing surface. As a result, the cooling device 2 can reliably ensure sealing strength. In addition, with the cooling device 2, the fastening strength can be increased by increasing the thickness of the first member 10, and since a separate member is not required to increase the fastening strength, the number of parts can be reduced and costs can be lowered.

[0029] Furthermore, the first member 10 has a positioning section 17 for determining the position of the heat sink 5. That is, the positioning section 17 is formed on the same member as the fastening hole 12, the inlet 13, and the outlet 14. Therefore, the position of the heat sink 5 relative to the fastening hole 12, the inlet 13, and the outlet 14 can be determined with high precision. Also, because the first member 10 has a positioning section 17, even if there are multiple heat sinks 5, these multiple heat sinks 5 can be easily positioned. Furthermore, by changing the shape of the opening 11 and the positioning section 17 in the first member 10, it is possible to accommodate changes in the shape and arrangement of the heat sink 5. In addition, the positioning section 17 is not provided in the entire area in the short direction within the opening 11, but only in a part of it (for example, 1 / 10 or less of the size in the short direction), so the resistance of cooling water flow in the space S is reduced. To reduce the resistance of water flow, it is desirable to form a chamfer at the upper end of the opening 11 and the positioning section 17 (in other words, the upper end of the surrounding surface 18).

[0030] The second member 20 is joined to the lower side of the first member 10 in the vertical direction (one example), and the third member 30 is joined to the upper side of the first member 10 in the vertical direction (the other example). Therefore, if the second member 20 and the third member 30 are formed from a clad material having a brazing layer, for example, the first member 10 can be joined to the second member 20 and the third member 30 without providing a brazing layer to the first member 10, thus allowing for flexibility in the thickness of the first member 10. In other words, if a clad material formed by rolling an aluminum alloy core and brazing material is used to form the first member 10, increasing the thickness of the first member 10 would result in a thicker brazing layer from the viewpoint of the cladding ratio. And if the thickness of the brazing layer is thicker, for example, the brazing material is more likely to fill the spaces between the fins 52 of the heat sink 5, which may lead to brazing defects. However, with the cooling device 2, there is no need to provide a brazing layer to the first member 10, so the thickness of the first member 10 can be given flexibility. As a result, the thickness of the first member 10 can be set to 20% or more of the vertical size of the cooling device 2. In addition, since brazing defects are less likely to occur between the fins 52 of the heat sink 5, it is possible to make the gap between the fins 52 1 mm or less.

[0031] The first member 10 has a recess 16 formed around the opening 11, which is recessed from the lower surface 15 of the first member 10 (an example of one side surface), and the second member 20 is fitted into the recess 16. Therefore, the difference in height between the lower surface 15 of the first member 10 and the lower surface of the second member 20 can be eliminated, making it possible to miniaturize the cooling device 2.

[0032] In the cooling device 2, the semiconductor module 100 is joined to the third member 30, and the third member 30 is joined to the first member 10. The size of the third member 30 in the short direction is smaller than the size of the first member 10 in the short direction. Therefore, a space is created between the lead frame 103 of the semiconductor module 100 and the first member 10. In other words, a larger space is created below the lead frame 103 of the semiconductor module 100 that can be used to insulate the lead frame 103. Furthermore, since a current sensor or the like can be placed below the lead frame 103 and outside the third member 30, the semiconductor device 1 can be made more compact.

[0033] In the embodiments described above, the heat sink 5, which has a flat plate portion 51, is exemplified as having a shape that at least a portion of it is housed in the opening 11 formed in the first member 10. However, the heat sink 5 may have a shape that does not have a flat plate portion 51. For example, the heat sink 5 may be a corrugated fin made of a metal plate bent into the shape of a wave propagating in the short direction. In the case of a corrugated fin, the gaps between the waves when viewed in the vertical direction may be parallel to the longitudinal direction, or they may be bent into the shape of a wave propagating in the longitudinal direction, or a portion in the longitudinal direction may be offset from other portions. Furthermore, the heat sink 5 may have multiple plate-shaped fin members arranged in a row in the short direction, with the plate shape being parallel to the longitudinal direction or in the shape of a wave propagating in the longitudinal direction, and these multiple separate fin members may be integrated by, for example, crimping. When the heat sink 5 does not have a flat plate portion 51, it is preferable that at least a portion of the fins be housed in the opening 11 formed in the first member 10 in the cooling device 2.

[0034] Furthermore, in the embodiments described above, the cooling device 2 has multiple (three in Figure 2) heat sinks 5 to correspond to each of the multiple (three in Figure 2) semiconductor modules 100, but the number of heat sinks 5 is not limited. For example, one heat sink 5 may be provided to correspond to all of the multiple (three in Figure 2) semiconductor modules 100.

[0035] <Second Embodiment> Figure 4 is a diagram showing an example of the external appearance of the cooling device 22 according to the second embodiment. Figure 4(a) is an example of a view of the cooling device 22 from diagonally above, and Figure 4(b) is an example of a view of the cooling device 22 from diagonally below. Figure 5 is an example of a diagram showing the components constituting the semiconductor device 21 according to the second embodiment disassembled. Figure 6 is a diagram showing an example of a cross-section of the semiconductor device 21 according to the second embodiment. Figure 6 is a cross-sectional view of the section VI-VI in Figure 4. The semiconductor device 21 according to the second embodiment differs from the semiconductor device 1 according to the first embodiment in that the cooling device 22 is equivalent to the cooling device 2. The differences from the first embodiment will be described below. The same reference numerals are used for the same parts in the first and second embodiments, and their detailed descriptions will be omitted.

[0036] In the cooling device 22 according to the second embodiment, the arrangement of the first member 210, which corresponds to the first member 10, and the third member 230, which corresponds to the third member 30, is different from that of the cooling device 2 according to the first embodiment. That is, in the cooling device 22, the first member 210 and the second member 20 are arranged below the semiconductor module 100, and the third member 230 is arranged below the first member 210.

[0037] The first member 210 according to the second embodiment differs from the first member 10 according to the first embodiment in that it does not have an inlet 13 and an outlet 14. In addition, the first member 210 according to the second embodiment has a recess 16 on its upper part. That is, the recess 16 is formed to be recessed from the upper surface of the first member 210.

[0038] The third member 230 according to the second embodiment has an inlet 234 corresponding to the inlet 13 and an outlet 235 corresponding to the outlet 14 formed on the third member 30 according to the first embodiment. The inlet 234 and the outlet 235 are each formed on both ends in the longitudinal direction.

[0039] The cooling device 22 configured as described above can be manufactured as follows. First, the second member 20 is fitted into the recess 16 of the first member 210, and a plurality of heat sinks 5 are fitted into the opening 11 of the first member 210. At this time, the heat sinks 5 are arranged so that at least a portion of the fins 52 are housed in the opening 11, so that the tips of the fins 52 of the heat sinks 5 contact the second member 20. In addition, the heat sink 5 provided at one end in the longitudinal direction of the plurality of heat sinks 5 is positioned between the one end in the longitudinal direction of the peripheral surface 18 of the first member 210 and the positioning portion 17. In addition, the heat sink 5 provided at the other end in the longitudinal direction of the plurality of heat sinks 5 is positioned between the other end in the longitudinal direction of the peripheral surface 18 of the first member 210 and the positioning portion 17. In addition, the heat sinks 5 that are not provided at the longitudinal ends of the plurality of heat sinks 5 are positioned between the positioning portions 17. Furthermore, when fitting multiple heat sinks 5 into the opening 11 of the first member 210, the multiple heat sinks 5 may be placed on the second member 20, similar to the manufacturing method of the cooling device 2 described above. After that, the flange 33 of the third member 230 is placed on the upper surface 19 of the first member 210. Then, the first member 210 and the second member 20, the first member 210 and the third member 230, and the tips of the fins 52 of the heat sink 5 and the second member 20 are brazed together. Also, the flat plate portion 51 of the heat sink 5 and the bottom portion 31 of the third member 230 are brazed together.

[0040] The cooling device 22 may also be manufactured as follows. First, multiple heat sinks 5 are placed on the bottom 31 of the third member 230 so that the flat surface 512 of the flat plate portion 51 of the heat sink 5 contacts the bottom 31 of the third member 230. Then, the first member 210 is placed on the flange 33 of the third member 230. At this time, the heat sink 5 provided at one end in the longitudinal direction of the multiple heat sinks 5 is positioned between the one end in the longitudinal direction of the peripheral surface 18 of the first member 210 and the positioning portion 17. Also, the heat sink 5 provided at the other end in the longitudinal direction of the multiple heat sinks 5 is positioned between the other end in the longitudinal direction of the peripheral surface 18 of the first member 210 and the positioning portion 17. Also, the heat sinks 5 that are not provided at the longitudinal ends of the multiple heat sinks 5 are positioned between the positioning portions 17. After that, the second member 20 is fitted into the recess 16 of the first member 210. Subsequently, the first member 210 and the second member 20, the first member 210 and the third member 230, and the flat plate portion 51 of the heat sink 5 and the third member 230 are brazed together. In addition, the tip of the fin 52 of the heat sink 5 and the second member 20 are brazed together.

[0041] After manufacturing the cooling device 22, the semiconductor device 21 is manufactured by joining the copper plate of the insulating substrate 101 of the semiconductor module 100 to the second member 20 of the cooling device 22 using, for example, solder or sintered metal (for example, silver, copper). When soldering the copper plate of the insulating substrate 101 of the semiconductor module 100 to the second member 20, the second member 20 may be nickel-plated. Alternatively, when silver-sintering the copper plate of the insulating substrate 101 of the semiconductor module 100 to the second member 20, the second member 20 may be silver-plated.

[0042] (Characteristics of cooling device 22) The cooling device 22 includes: a heat sink 5 having a flat plate portion 51 and fins 52 protruding from the flat plate portion 51 in a vertical direction intersecting the plate surface; and a first member 210 formed with an opening 11 that accommodates at least a part of the fins 52. The cooling device 22 further includes: a second member 20 that is of a flat plate shape and closes the opening 11 of the first member 210; and a third member 230 that together with the first member 210 and the second member 20 forms a space S that accommodates the heat sink 5 and allows cooling water to flow therethrough.

[0043] In the cooling device 22, a part of the fins 52 of the heat sink 5 is accommodated in the opening 11 of the first member 210, so compared with the cooling device according to the comparative example, even when the height of the fins 52 is the same, the size in the vertical direction is reduced. Therefore, according to the cooling device 22, size reduction can be achieved even when the heat dissipation performance is the same.

[0044] Furthermore, in the cooling device 22, the third member 230 is formed with an inflow port 234 for allowing cooling water to flow into the space S, and an outflow port 235 for allowing the liquid to flow out from the space S. The inflow port 234 and the outflow port 235 are provided outside the heat sink 5 in the longitudinal direction. Therefore, the size of the cooling device 22 in a direction orthogonal to the flow direction of the cooling water (for example, the lateral direction) can be reduced.

[0045] Furthermore, in the cooling device 22, the second member 20 is joined to the upper side in the vertical direction of the first member 210 (an example of one side), and the third member 230 is joined to the lower side in the vertical direction of the first member 210 (an example of the other side). Therefore, when the second member 20 and the third member 230 are formed of, for example, a clad material having a brazing filler metal layer, they can be joined to the second member 20 and the third member 230 without providing a brazing filler metal layer on the first member 210. As a result, a degree of freedom can be provided for the thickness of the first member 210.

[0046] Figure 7 shows an example of a modified third member 230. As shown in Figure 7, a reinforcing member 240 may be provided around the inlet 234 at the bottom 31 of the third member 230 to increase the strength and rigidity of the area around the inlet 234. By providing the reinforcing member 240, the thickness of the area around the inlet 234 can be increased, thereby increasing the rigidity of the area around the inlet 234, and thus improving the sealing performance of the cooling water flowing through the inlet 234. The reinforcing member 240 is preferably provided over the entire area outside the part of the bottom 31 of the third member 230 where the flat plate portion 51 of the heat sink 5 is joined.

[0047] The reinforcing member 240 is provided in a recess (in other words, in space S) formed by the bottom portion 31 and the side portion 32. This makes it possible to improve sealing performance without affecting the vertical size of the cooling device 22. Furthermore, it can be exemplified that the reinforcing member 240 is brazed to the third member 230 using brazing material from the cladding material which is the material of the third member 230. In other words, instead of increasing the thickness of the third member 230 to increase the thickness of the portion around the inlet 234, a reinforcing member 240, which is a separate part from the third member 230, is used. This prevents the thickness of the brazing material layer from becoming too thick due to increasing the thickness of the third member 230, which could result in problems such as brazing defects between the fins 52 of the heat sink 5. Although not shown in the figures, the reinforcing member 240 may also be provided around the outlet 235 to increase the strength and rigidity of the portion around the outlet 235.

[0048] 1, 21... Semiconductor device, 2, 22... Cooling device, 5... Heat sink, 10, 210... First member, 11... Opening, 12... Fastening hole (example of a through hole), 13, 234... Inlet, 14, 235... Outlet, 16... Recess, 17... Positioning part, 20... Second member, 30, 230... Third member, 51... Flat plate-shaped part, 52... Fin, 100... Semiconductor module, 102... Semiconductor element, S... Space

Claims

1. A cooling device comprising: a heat sink having fins; a first member which is flat and has an opening formed therein for accommodating at least a portion of the fins; a second member which is flat and closes the opening of the first member; and a third member which, together with the first member and the second member, accommodates the heat sink and forms a space through which a refrigerant flows.

2. The cooling device according to claim 1, wherein the first member has an inlet for introducing a refrigerant into the space and an outlet for discharging liquid from the space.

3. The cooling device according to claim 1, wherein the third member has an inlet for introducing refrigerant into the space and an outlet for discharging liquid from the space.

4. The cooling device according to claim 1, wherein the first member has a through hole through which the shaft portion of the fastening member can pass.

5. The cooling device according to claim 1, wherein the first member has a positioning portion for determining the position of the heat sink.

6. The cooling device according to claim 1, wherein the second member is joined to one side of the first member, and the third member is joined to the other side of the first member.

7. The cooling device according to claim 1, wherein the first member has a recess formed around the opening, recessed from one side of the first member, and the second member is fitted into the recess.

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