COOLING DEVICE

Abstract

A cooling device is provided for cooling a plurality of power modules, each comprising a substrate body and a semiconductor element arranged on a surface of the substrate body and lined up in a first direction. The cooling device includes a cooling member having a heat transfer surface and configured to contact a back surface of each of the substrate bodies, and a flow path forming member having an upper surface portion and a lower surface portion and forming a flow path through which a refrigerant flows in the first direction between the lower surface portion and the upper surface portion. In the flow path, the flow path cross-sectional area of ​​the flow path decreases from an upstream side to a downstream side in a flow direction of the refrigerant.Each flow-disturbing region configured to disturb the flow of the refrigerant is provided in a region between the power modules in the flow path forming member.

Description

TECHNICAL FIELD

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

[0002] Priority is claimed for Japanese Patent Application No. 2022-198364, filed on December 13, 2022, the contents of which are hereby incorporated by reference. STATE OF THE ART

[0003] For example, in a power module used in a power supply circuit, a large current flows through a semiconductor element in the power module. Therefore, a large amount of heat is generated due to conduction and switching losses occurring in the semiconductor element. If this heat is gradually generated, there is a possibility of thermal burnout or damage to an element. Therefore, various cooling devices have been proposed to cool the power module. Specific examples of cooling devices are those described in Patent Document 1.

[0004] In the device according to Patent Document 1, a cooling element having a heat radiation fin is mounted on a lower surface of a plurality of circuit boards. Furthermore, a flow path is formed on the lower surface of the circuit board, through which a refrigerant flows to contact the heat radiation fin. The flow path cross-sectional area of ​​the flow path gradually decreases from an upstream side to a downstream side in a flow direction of the refrigerant. Citation listPatent document

[0005] Patent Document 1: Unexamined Japanese Patent Application, First Publication No. 2010-153785 SUMMARY OF THE INVENTIONTechnical Problem

[0006] Here, since the semiconductor element used in the above-described power supply circuit or the like may reach a considerable temperature, it is conceivable that a temperature of a heat transfer surface exceeds a boiling point and a cooling medium boils. In this case, in the device disclosed in Patent Document 1, air bubbles form in a gap between the heat radiation fins. If the air bubbles continue to remain in the gap, the air bubbles are trapped between the heat radiation fin and the refrigerant. As a result, the power module is brought into an adiabatic state, a so-called dry state. This means that a cooling effect achieved by the refrigerant cannot be maintained.This causes the cooling of the semiconductor element to become unstable and results in the temperature of the element rising excessively, creating the possibility of thermal destruction.

[0007] The present disclosure has been made to solve the problems described above, and an object of the present disclosure is to provide a cooling device that can stably cool a semiconductor element. Solution to the problem

[0008] According to the present disclosure, to solve the above-described problem, a cooling device for cooling a plurality of power modules is provided, each comprising a substrate body and a semiconductor element arranged on a surface of the substrate body and arrayed in a first direction. The cooling device includes a cooling member having a heat transfer surface and provided in contact with a back surface of each of the substrate bodies, and a flow path forming member including an upper surface portion in which an opening portion surrounding the heat transfer surface is formed and a lower surface portion facing the upper surface portion at an interval, forming a flow path through which a refrigerant flows in the first direction between the lower surface portion and the upper surface portion.In the flow path, the flow path cross-sectional area decreases from an upstream side to a downstream side in a refrigerant flow direction. Each flow-disturbing region configured to disturb the flow of the refrigerant is provided in a region between the power modules in the flow path forming member.

[0009] According to the present disclosure, a cooling device for cooling a plurality of power modules is provided, each comprising a substrate body and a semiconductor element arranged on a surface of the substrate body and arrayed in a first direction. The cooling device includes a cooling member including a heat transfer surface and provided in contact with a back surface of each of the substrate bodies, and a flow path forming member including an upper surface portion in which an opening portion surrounding the heat transfer surface is formed and a lower surface portion facing the upper surface portion at an interval, and forming a flow path through which a refrigerant flows in the first direction between the lower surface portion and the upper surface portion.In the flow path, the flow path cross-sectional area decreases from an upstream side to a downstream side in a flow direction of the refrigerant. The cooling element includes a cooling element body configured to contact the substrate body and a plurality of protrusions protruding from the cooling element body toward the lower surface region. The protrusion length of the protrusion is equal to or less than the thickness of the upper surface region. Advantageous effects of the invention

[0010] According to the present disclosure, it is possible to provide a cooling device that can stably cool a semiconductor element. BRIEF DESCRIPTION OF THE DRAWINGS [ Fig. 1] A cross-sectional view showing the configuration of a cooling device according to a first embodiment of the present disclosure. [ Fig. 2] A cross-sectional view showing a first modification example of the cooling device according to the first embodiment of the present disclosure. [ Fig. 3] A cross-sectional view showing a second modification example of the cooling device according to the first embodiment of the present disclosure. [ Fig. 4] A cross-sectional view showing the configuration of a cooling device according to a second embodiment of the present disclosure. [ Fig. 5] A cross-sectional view showing the configuration of a cooling device according to a third embodiment of the present disclosure. [ Fig. 6] A cross-sectional view showing a modification example of the cooling device according to the third embodiment of the present disclosure. DESCRIPTION OF THE EMBODIMENTS<Erste Ausführungsform> (Configuration of the circuit system)

[0011] Hereinafter, a cooling device 1 according to a first embodiment of the present disclosure will be described with reference to Fig. 1. The cooling device 1 is a device for cooling a semiconductor element 21 used in a circuit system 90 that processes a large current, such as a power supply circuit.

[0012] As in Fig. 1, the circuit system 90 includes a plurality of power modules 2 and the cooling device 1.

[0013] The power module 2 includes a substrate body 20 and the semiconductor element 21. The substrate body 20 includes an insulator 20a and a pattern 20b (connecting material). The insulator 20a is in the form of a plate made of a material such as alumina, silicon nitride, or aluminum nitride, for example. Circuit patterns 20b and 20c made of copper foil are formed on both surfaces of the insulator 20a in the thickness direction. The semiconductor element 21 is electrically connected to the pattern 20b by a conductive connecting member 20d such as solder. The semiconductor element 21 is, for example, a MOSFET or a power transistor, and a current flows in the semiconductor element 21, so heat is generated due to internal resistance. In addition, the pattern 20b and the cooling element 10 (described later) are connected by the connecting member 20e in the same way.

[0014] A plurality of (e.g., three) semiconductor elements 21 are mounted on one surface of the substrate body 20. The number of semiconductor elements 21 is not limited to three, but may be two or fewer, four or more. The cooling device 1 is located on the back side of the substrate body 20 (i.e., on the side opposite a surface on which the semiconductor element 21 is mounted). (Cooling device configuration)

[0015] The cooling device 1 includes a cooling element 10 and a flow path forming member 11. The cooling element 10 includes a cooling element body 12 and a plurality of protrusions 13. The cooling element body 12 has the shape of a plate that comes into contact with a back surface of the substrate body 20. The protrusion 13 protrudes from the back surface of the cooling element body 12. The plurality of protrusions 13 are arranged at an interval from each other. Specific examples of a shape of the protrusion 13 are a fin and a pin. A surface on one side including the protrusion 13 in the cooling element 10 is defined as a heat transfer surface 14. The heat transfer surface 14 described here is a surface with asperities, including an outer surface such as a side surface or a tip surface of the protrusion 13. The cooling element 10 is integrally formed from a metal with a high heat transfer rate, such as aluminum or copper.The cooling element 10 may also be configured such that the cooling element body 12 and the projection 13 are connected to each other after being formed as separate elements.

[0016] The flow path forming member 11 forms a flow path 30 for flowing a refrigerant on the heat transfer surface 14 of the cooling element 10. The flow path forming member 11 includes an upper surface portion 41, a lower surface portion 42, and a flow-disturbing portion 43. The upper surface portion 41 has a plate shape extending along an extending surface of the power module 2. A plurality of power modules 2 are arranged at an interval from each other on the upper surface portion 41. Hereinafter, a direction in which the power modules 2 are arranged may be referred to as a "first direction." A plurality of opening portions 50 surrounding the heat transfer surface 14 are formed in the upper surface portion 41. That is, each heat transfer surface 14 is exposed in the flow path 30 through the opening portion 50.The protrusion length of the protrusion 13 is equal to or smaller than the thickness of the upper surface portion 41. That is, viewed in the first direction, the protrusion 13 is accommodated in the opening portion 50 and does not protrude into the flow path 30.

[0017] The lower surface portion 42 faces the upper surface portion 41 with an interval therebetween. A space formed between the upper surface portion 41 and the lower surface portion 42 forms the flow path 30 through which the refrigerant flows. In the flow path 30, the refrigerant flows from one side to the other side in the first direction. A suitable refrigerant, for example, is a liquid such as ethylene glycol or pure water. In the following description, a side to which the refrigerant flows in the first direction may be referred to as an "upstream side," and a side opposite it may be referred to as a "downstream side."

[0018] A plurality of flow-disturbing regions 43 are formed in the lower surface region 42. In the present embodiment, a plurality of step-difference regions 60 are formed as the flow-disturbing regions 43. Each of the step-difference regions 60 includes a step-difference surface 61, which is a surface facing the upstream side. In this way, a surface of the lower surface region 42 gradually approaches a side of the upper surface region 41 from the upstream side to the downstream side. In the first direction, the step-difference region 60 is located between a pair of adjacent printed circuit boards 2. That is, a surface facing the heat transfer surface 14 in the lower surface region 42 extends in a plane parallel to the substrate body 20.Since the surface has this shape, the flow path cross-sectional area of ​​the flow path 30 gradually decreases from the upstream side to the downstream side. (Operational effect)

[0019] During operation of the cooling device 1, the refrigerant is first caused to flow in the flow path 30. When a current flows to the semiconductor element 21 in this state, the semiconductor element 21 generates heat due to its internal resistance. As heat generation increases, there is a possibility of thermal runaway of the semiconductor element 21 or damage to the semiconductor element 21. Therefore, the cooling device 1 cools the semiconductor element 21. Specifically, the refrigerant continuously flowing in the flow path 30 comes into contact with the heat transfer surface 14. In this way, the heat of the semiconductor element 21 is dissipated via the substrate body 20. That is, the semiconductor element 21 itself is cooled by the refrigerant.

[0020] Here, when a plurality of power modules 2 are arranged in the above-described first direction and the refrigerant flows in the first direction, the temperature of the refrigerant to be supplied increases the closer the refrigerant is to the power module 2 on the downstream side. Therefore, there is a possibility that a cooling effect on the semiconductor element 21 on the downstream side is limited. To reduce this possibility, the cooling device 1 according to the present embodiment adopts any of the configurations described above.

[0021] According to the configuration described above, the flow path cross-sectional area of ​​the flow path 30 decreases toward the downstream side. Thus, the flow velocity of the refrigerant increases toward the downstream side. As the flow velocity increases, the thickness of a boundary layer formed near a surface of the upper surface region 41 or the lower surface region 42 decreases. Therefore, the heat transfer rate of the refrigerant obviously increases. Thus, the heat transfer rate of the refrigerant toward the power module 2 on the downstream side increases, and the cooling effect can be improved. As a result, the power module 2 can operate more stably.

[0022] Furthermore, the flow direction of the refrigerant is changed because the refrigerant flowing in the flow path 30 collides with the step difference surface 61 serving as the flow disturbing region 43. Specifically, the refrigerant flows in a direction from a side of the lower surface region 42 to a side of the upper surface region 41 by colliding with the step difference surface 61. Moreover, a vortex is likely to form on the downstream side of the step difference region 60. In this way, the refrigerant in which a temperature gradient is formed when supplied to cool the power module 2 on the upstream side is swirled on the upstream side of the step difference region 60. As a result, the refrigerant on the downstream side flows toward the power module 2 in a state where the temperature gradient is canceled.Therefore, since a temperature rise on one side of the heat transfer surface 14 of the refrigerant flowing to the downstream side is suppressed, the cooling effect on the power module 2 on the downstream side can be further improved.

[0023] Furthermore, according to the above-described configuration, the flow path cross-sectional area 30 can be reduced toward the downstream side only by forming the step difference region 60. Thus, the flow velocity of the refrigerant increases toward the downstream side. Moreover, the refrigerant collides with the step difference surface 61 of the step difference region 60. Accordingly, a flow disturbance including a vortex is generated on the downstream side of the step difference region 60. As a result, the refrigerant is disturbed as described above, and the temperature gradient of the refrigerant is canceled. Accordingly, the cooling effect on the power module 2 on the downstream side can be slightly improved.

[0024] Furthermore, according to the above-described configuration, the protrusion length of the protrusion 13 of the cooling member 10 is equal to or smaller than the thickness of the upper surface portion 41. Thus, even if air bubbles are generated in a gap between the protrusions 13 due to boiling of the refrigerant, a flow of the refrigerant is likely to reach the inside of the gap after rising above the protrusions 13. Therefore, the air bubbles present in the gap can be easily carried away by the flow of the refrigerant. This can further reduce the possibility of drying out due to the air bubbles present between the heat transfer surface 14 and the refrigerant. In this way, the cooling effect on the semiconductor element 21 can be further improved.

[0025] So far, the first embodiment of the present disclosure has been described. Various changes or modifications may be made to the above-described configuration without departing from the concept of the present disclosure.

[0026] For example, as in Fig. 2 as a first embodiment, a further flow-disturbing region 43 (upstream flow-disturbing region 44) may be provided on the further upstream side of the power module 2 on an uppermost flow side in the lower surface region 42. In the example of Fig. 2, another step difference region 60 is further formed as the upstream flow-disturbing region 44. According to this configuration, when air bubbles are generated due to the boiling of the refrigerant on the surface (heat-transfer surface 14) of the cooling element 10 corresponding to the power module 2 on the uppermost flow side, the refrigerant passing through the upstream flow-disturbing region 44 flows toward the heat-transfer surface 14. In this way, the refrigerant can flow between the protrusions 13, and the air bubbles can be carried away by the flow of the refrigerant. As a result, the cooling effect can be continuously maintained by preventing the heat-transfer surface 14 from drying out.

[0027] As in Fig. 3 as a second modification example, it is also possible to adopt a configuration in which the step difference surface 61 is inclined. More specifically, the step difference surface 61 is inclined from a side of the lower surface portion 42 to a side of the upper surface portion 41 from the upstream side to the downstream side. According to this configuration, the step difference surface 61 can reduce a pressure loss of the refrigerant when the refrigerant passes through the step difference surface 61, in addition to an operating effect achieved by the above-described flow disturbance. In this way, the flow of the refrigerant is further balanced, and the cooling effect on each power module 2 can be further improved. <Zweite Ausführungsform>

[0028] Hereinafter, a second embodiment of the present disclosure will be described with reference to Fig. 4. The same reference numerals are assigned to the same configurations as in the first embodiment described above, and a detailed description thereof is omitted. As in Fig. As shown in FIG. 4, in the present embodiment, each upper surface-side protrusion portion 45 is provided as flow-disturbing portions 43 between the power modules 2 in the upper surface region 41. The upper surface-side protrusion portion 45 protrudes in a direction from the upper surface region 41 to one side of the lower surface region 42. Moreover, the upper surface-side protrusion portion 45 is provided at a position overlapping the step difference portion 60 of the lower surface region 42 in the first direction. The upper surface-side protrusion portion 45 may be provided on a slightly upstream side or downstream side of the step difference portion 60. (Operational effect)

[0029] According to the configuration described above, the flow of the refrigerant climbing over the upper surface-side protrusion portion 45 is disrupted by the upper surface-side protrusion portion 45. Thus, the refrigerant is swirled, and the refrigerant flows to the downstream side in a state where the temperature gradient from a side of the upper surface portion 41 to a side of the lower surface portion 42 is eliminated. Since a temperature rise on a side of the heat transfer surface 14 of the refrigerant flowing to the downstream side is suppressed, the cooling effect on the power module 2 on the downstream side can be further improved.

[0030] So far, the second embodiment of the present disclosure has been described. Various changes or modifications may be made to the above-described configuration without departing from the concept of the present disclosure. <Dritte Ausführungsform>

[0031] Next, a third embodiment of the present disclosure will be described with reference to Fig. 5. The same reference numerals are assigned to the same configurations as in each of the above-described embodiments, and a detailed description thereof is omitted. As in Fig. 5, in the present embodiment, a surface of the lower surface portion 142 is continuously inclined to approach the upper surface portion 41 from the upstream side to the downstream side. That is, the step difference portion 60 is not formed in the lower surface portion 142 itself. In this way, the flow path cross-sectional area 30 gradually decreases toward the downstream side. Moreover, a lower surface-side protrusion portion 46 serving as the flow disturbing portion 43 is provided on a surface of the bottom surface portion 142. The lower surface-side protrusion portion 46 protrudes from the surface of the lower surface portion 142 toward one side of the upper surface portion 41. The lower surface-side protrusion portion 46 is located between the pair of power modules 2 that are adjacent to each other in the first direction. (Operational effect)

[0032] According to the above-described configuration, the lower surface portion 142 is inclined toward one side of the upper surface portion 41 because the lower surface portion 142 faces the downstream side. In this way, the pressure loss generated in the refrigerant can be minimized, for example, compared with a case where a step difference or the like is provided in the lower surface portion 142. This balances the flow of the refrigerant, and fresh refrigerant is always supplied to the downstream side. Therefore, a further improved cooling effect can be achieved.

[0033] Furthermore, according to the above-described configuration, since the lower surface-side protrusion portion 46 is provided, the flow of the refrigerant rising above the lower surface-side protrusion portion 46 is disturbed. Thus, the refrigerant is swirled, and the refrigerant flows to the downstream side in a state where the temperature gradient from the upper surface portion 41 side to the lower surface portion 142 side is eliminated. Since a temperature rise on the heat transfer surface 14 side of the refrigerant flowing to the downstream side is suppressed, the cooling effect on the power module 2 on the downstream side can be further improved.

[0034] So far, the third embodiment of the present disclosure has been described. Various changes or modifications may be made to the above-described configuration without departing from the concept of the present disclosure.

[0035] As in Fig. 6 as a modification example, for example, the upper surface-side protrusion portion 45 described in the second embodiment may be provided in the upper surface portion 41. In this case, the positions of the upper surface-side protrusion portion 45 and the lower surface-side protrusion portion 46 in the first direction may coincide with each other or be slightly shifted to the upstream side or the downstream side. With this configuration, the same operational effects as described above can be achieved. <anhang>

[0036] The cooling device 1 described in the individual embodiments is understood to mean, for example, the following. (1) According to a first aspect, the cooling device 1 is provided for cooling the plurality of power modules 2, each comprising the substrate body 20 and the semiconductor element 21 arranged on the surface of the substrate body 20 and lined up in the first direction. The cooling device 1 includes the cooling member 10, which includes the heat transfer surface 14 and is provided in contact with the back surface of each of the substrate bodies 20, and a flow path forming member 11, which includes the upper surface portion 41 in which the opening portion 50 surrounding the heat transfer surface 14 is formed, and the lower surface portion 42 facing the upper surface portion 41 with an interval therebetween, and forms the flow path 30 through which the refrigerant flows in the first direction between the lower surface portion 42 and the upper surface portion 41.In the flow path 30, the flow path cross-sectional area decreases from the upstream side to the downstream side in the refrigerant flow direction. Each flow-disturbing region 43 configured to disturb the flow of the refrigerant is provided in the region between the power modules 2 in the flow path forming member 11.

[0037] According to the configuration described above, the flow path cross-sectional area 30 decreases toward the downstream side. Thus, the flow velocity of the refrigerant increases toward the downstream side. As a result, as the refrigerant on the downstream side is closer to the power module 2, the heat transfer rate of the refrigerant increases, and the cooling effect can be improved. In addition, the refrigerant flowing in the flow path 30 encounters the flow disturbance region 43. This changes the flow direction of the refrigerant. In this way, the refrigerant in which the temperature gradient is formed when supplied to cool the power module 2 on the upstream side is swirled. As a result, the refrigerant flows to the power module 2 on the downstream side in a state where the temperature gradient is canceled.In this way, the cooling effect on the power module 2 on the downstream side can be further improved.

[0038] (2) As the cooling device 1 according to a second aspect, in the cooling device 1 according to (1), the flow disturbing portion 43 includes the upstream portion 60 having the step difference surface 61 facing the upstream side.

[0039] According to the above-described configuration, the flow path cross-sectional area of ​​the flow path 30 can be reduced toward the downstream side by forming the step difference region 60. Thus, the flow velocity of the refrigerant increases toward the downstream side. Furthermore, the refrigerant collides with the step difference surface 61 of the step difference region 60. Accordingly, a flow disturbance including a vortex is generated on the downstream side of the step difference region 60. This swirls the refrigerant, and the cooling effect on the power module 2 on the downstream side can be easily improved.

[0040] (3) As the cooling device 1 according to a third aspect, in the cooling device 1 according to (1) or (2), the flow disturbing portion 43 includes the upper surface side protrusion portion 45 protruding from the upper surface portion 41 toward the lower surface portion 42.

[0041] According to the configuration described above, the flow of the refrigerant climbing over the upper surface-side protrusion portion 45 is disrupted by the upper surface-side protrusion portion 45. Thus, the refrigerant is swirled, and the refrigerant flows to the downstream side in a state where the temperature gradient is eliminated. This can further enhance the cooling effect on the power module 2 on the downstream side.

[0042] (4) As the cooling device 1 according to a fourth aspect, in the cooling device 1 according to any one of the aspects (1) to (3), the flow disturbing portion 43 includes the lower surface side protrusion portion 46 protruding from the lower surface portion 42 toward the upper surface portion 41.

[0043] According to the configuration described above, the flow of the refrigerant climbing over the lower surface-side protrusion portion 46 is disrupted due to the presence of the lower surface-side protrusion portion 46. Thus, the refrigerant is swirled, and the refrigerant flows to the downstream side in a state where the temperature gradient is eliminated. This further enhances the cooling effect on the power module 2 on the downstream side.

[0044] (5) As a cooling device 1 according to a fifth aspect, in the cooling device 1 according to any one of the aspects (1) to (4), the lower surface portion 142 is inclined toward a side of the upper surface portion 41 from the upstream side to the downstream side.

[0045] According to the configuration described above, the lower surface portion 142 is inclined toward one side of the upper surface portion 41 because the lower surface portion 142 faces the downstream side. In this way, compared with, for example, a case where a step difference or the like is provided in the lower surface portion 142, a pressure loss generated in the refrigerant can be suppressed. As a result, the flow of the refrigerant is balanced, and a further improved cooling effect can be achieved.

[0046] (6) As the cooling device 1 according to a sixth aspect, the cooling device 1 according to any one of (1) to (5) further comprises the upstream flow disturbing portion 44 provided on the further upstream side of the power module 2 on the uppermost flow side in the lower surface portion 42.

[0047] According to the above-described configuration, the upstream region 44 is provided to disrupt the flow. When air bubbles are generated due to the boiling of the refrigerant on the surface (heat transfer surface 14) of the cooling element 10 corresponding to the power module 2 on the uppermost stream side, the refrigerant flowing through the upstream region 44 flows toward the heat transfer surface 14. Accordingly, the air bubbles can be flowed away. As a result, the cooling effect can be continuously maintained by preventing the occurrence of dryness of the heat transfer surface 14.

[0048] (7) As a cooling device 1 according to a seventh aspect, in the cooling device 1 according to any one of aspects (1) to (6), the cooling element 10 includes the cooling element body 12 configured to contact the substrate body 20, and the plurality of protrusions 13 protruding from the cooling element body 12 toward the lower surface portion 42. The protrusion length of the protrusions 13 is equal to or smaller than the thickness of the upper surface portion 41.

[0049] According to the above-described configuration, the protrusion length of the protrusion 13 of the cooling element 10 is equal to or less than the thickness of the upper surface portion 41. Thus, even if air bubbles are generated in the gap between the protrusions 13 due to boiling of the refrigerant, the refrigerant flow easily reaches the inside of the gap. Therefore, the air bubbles can be easily carried away by the refrigerant flow. This further reduces the possibility of dryout.

[0050] (8) According to an eighth aspect, the cooling device 1 is provided for cooling the plurality of power modules 2, each comprising the substrate body 20 and the semiconductor element 21 arranged on the surface of the substrate body 20 and lined up in the first direction. The cooling device 1 includes the cooling member 10 including the heat transfer surface 14 and provided in contact with the back surface of each of the substrate bodies 20, and a flow path forming member 11 including the upper surface portion 41 in which the opening portion 50 surrounding the heat transfer surface 14 is formed, and the lower surface portion 42 facing the upper surface portion 41 with an interval therebetween, and forming the flow path 30 through which the refrigerant flows in the first direction between the lower surface portion 42 and the upper surface portion 41.In the flow path 30, the cross-sectional area of ​​the flow path decreases from the upstream side to the downstream side in the flow direction of the refrigerant. The cooling element 10 includes the cooling element body 12 configured to contact the substrate body 20, and the plurality of protrusions 13 protruding from the cooling element body 12 toward the lower surface region 42. The protrusion length of the protrusions 13 is equal to or less than the thickness of the upper surface region 41.

[0051] According to the above-described configuration, the flow path cross-sectional area of ​​the flow path 30 decreases toward the downstream side. Thus, the flow velocity of the refrigerant increases toward the downstream side. As a result, the heat transfer rate of the refrigerant increases as the refrigerant on the downstream side is closer to the power module 2, and the cooling effect can be improved. Moreover, the protrusion length of the protrusion 13 of the cooling member 10 is equal to or smaller than the thickness of the upper surface portion 41. Thus, even if air bubbles are generated in the gap between the protrusions 13 due to boiling of the refrigerant, the flow of the refrigerant easily reaches the inside of the gap. Therefore, the air bubbles can be easily carried away by the flow of the refrigerant. This further reduces the possibility of dryout. INDUSTRIAL APPLICABILITY

[0052] According to the present disclosure, it is possible to provide a cooling device that can permanently cool a semiconductor element. REFERENCE SYMBOL LIST 1 cooling device 2 power module 10 Cooling element 11 Flow path forming element 12 cooling element bodies 13 lead 14 Heat transfer surface 20 substrate bodies 20a insulator 20b Pattern 20c sample 20d connecting element 20e connecting element 21 semiconductor element 30 Flow path 41 Upper surface area 42 Lower surface area 43 flow-disturbing area 44 upstream flow-disturbing area 45 Upper surface-side projection area 46 Lower surface-side projection area 50 opening area 60 step difference range 61 Step difference surface 90 circuit system 142 Lower surface area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-198364

[0002] JP 2010-153785

[0005] < / anhang>

Claims

[1] A cooling device for cooling a plurality of power modules, each of which comprises a substrate body and a semiconductor element arranged on a surface of the substrate body and arrayed in a first direction, the cooling device comprising: a cooling element comprising a heat transfer surface in contact with the back surface of each of the substrate bodies; and a flow path forming member comprising an upper surface region in which an opening region surrounding the heat transfer surface is formed, and a lower surface region facing the upper surface region at an interval, and forming a flow path through which a refrigerant flows in the first direction between the lower surface region and the upper surface region, wherein in the flow path, a flow path cross-sectional area decreases from an upstream side to a downstream side in a flow direction of the refrigerant, and each flow-disturbing region configured to disturb the flow of the refrigerant is provided in a region between the power modules in the flow path forming member. [2] The cooling device according to claim 1, wherein the flow disturbing portion comprises a step difference portion comprising a step difference surface facing the upstream side. [3] The cooling device according to claim 1 or 2, wherein the flow disturbing portion comprises an upper surface-side protrusion portion protruding from the upper surface portion toward the lower surface portion. [4] The cooling device according to claim 1, wherein the flow disturbing portion comprises a lower surface side protrusion portion protruding from the lower surface portion toward the upper surface portion. [5] The cooling device according to claim 1, wherein the lower surface portion is inclined toward a side of the upper surface portion from the upstream side to the downstream side. [6] The cooling device according to claim 1, further comprising: an upstream flow-disturbing region provided on a further upstream side of the power module and located on the uppermost flow side in the lower surface area. [7] The cooling device according to claim 1, wherein the cooling element comprises a cooling element body configured to come into contact with the substrate body, and a plurality of projections projecting from the cooling element body toward the lower surface region, and a projection length of the projection is equal to or less than the thickness of the upper surface region. [8] A cooling device for cooling a plurality of power modules each comprising a substrate body and a semiconductor element arranged on a surface of the substrate body and lined up in a first direction, the cooling device comprising: a cooling element having a heat transfer surface in contact with the back of each of the substrate bodies; and a flow path forming member comprising an upper surface region in which an opening region surrounding the heat transfer surface is formed, and a lower surface region facing the upper surface region at a distance, and forming a flow path through which a refrigerant flows in the first direction between the lower surface region and the upper surface region, wherein in the flow path, a flow path cross-sectional area decreases from an upstream side to a downstream side in a flow direction of the refrigerant, the cooling element includes a cooling element body configured to come into contact with the substrate body, and a plurality of projections projecting from the cooling element body toward the lower surface region, and a projection length of the projection is equal to or less than the thickness of the upper surface region.

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