Water-cooling heat dissipation structure and power module

Abstract

A water-cooling heat dissipation structure comprises a cooling shell and a heat dissipation substrate, a cooling flow channel is arranged in the cooling shell, a plurality of heat dissipation pin fins are arranged on the heat dissipation substrate and extend to the cooling flow channel, a flow guide part is arranged in the cooling flow channel, and the flow guide part and the heat dissipation substrate are oppositely arranged on the two sides of the cooling shell and provided with insertion holes. A power module comprises a power chip, a packaging structure and a water-cooling heat dissipation structure. Flow deflection and flow guiding are conducted on the cooling flow channel through the flow guiding piece, the flowing sectional area is suddenly reduced, the continuously-flowing cooling working medium is forced to be accelerated, and the heat exchange performance of the heat dissipation pin fins can be improved by increasing the flow speed; due to the suddenly-raised flow section, the low-temperature cooling working medium in the bottom area of the heat dissipation pin fins is forced to be raised to be mixed with the high-temperature cooling working medium near the heat dissipation substrate, the highest temperature of the cooling working medium near the heat dissipation substrate is greatly reduced, and the negative influence caused by the great temperature rise of the cooling working medium near the heat dissipation substrate in the flowing direction is eliminated; therefore, the heat dissipation of the local area of the heat dissipation substrate is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic devices, and in particular to a water-cooling heat dissipation structure and a power module with the water-cooling heat dissipation structure. Background Art

[0002] As the electric drive system develops towards high integration and high power, the power requirements of power modules are getting higher and higher, while the volume and weight requirements are becoming increasingly lightweight and miniaturized, which makes the heat dissipation requirements of power modules higher and higher. The traditional pure water cooling method is no longer sufficient to meet the heat dissipation needs of power modules. In addition, since the temperature of the coolant gradually rises after absorbing heat, the cooling effect is reduced, resulting in the temperature difference of the power chip junction temperature upstream and downstream of the water cooling structure reaching up to 15°C or more, which seriously affects the output capacity of the module.

[0003] Patent document CN 113670099 A discloses a power battery liquid cooling plate structure, which relates to the field of thermal management technology of power batteries for new energy vehicles, including a plate substrate, the interior of the plate substrate is hollowed out to form a flow cavity, and a plurality of fins arranged at unequal intervals are arranged in the flow cavity, and the plurality of fins are arranged in multiple rows in the flow cavity, and the plurality of fins separate the flow cavity into a plurality of flow channels that are interconnected and have different cross-sections. This technical solution can enhance heat dissipation in a local area of ​​the power battery liquid cooling plate through a fin density design, but the fin density is limited by the processing technology, and the effect of enhanced heat dissipation is also greatly limited. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a water-cooling heat dissipation structure which is simple in structure, low in cost, conducive to improving heat exchange efficiency and does not affect the upstream packaging process and original structure of the power device.

[0005] The present invention further provides a power module including the water-cooling heat dissipation structure.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A water-cooled heat dissipation structure comprises a cooling shell and a heat dissipation substrate arranged on the cooling shell, a cooling channel is arranged inside the cooling shell, a plurality of heat dissipation pin fins are arranged on the heat dissipation substrate and extend into the cooling channel, a guide is arranged in the cooling channel, the guide is arranged on two sides of the cooling shell opposite to the heat dissipation substrate, and a socket is provided on the guide for inserting the heat dissipation pin fins.

[0008] As a further improvement of the above technical solution: the heat dissipation substrate is arranged on the upper part of the cooling shell, the guide member is connected to the lower part of the cooling shell, and there is a gap between the heat dissipation substrate and the guide member.

[0009] As a further improvement of the above technical solution: the insertion hole is a through hole, and the lower end of the heat dissipation pin fin inserted into the insertion hole abuts against the lower part of the cooling shell.

[0010] As a further improvement of the above technical solution: the upper part of the guide member is a slope structure and the height of the slope gradually increases along the flow direction of the cooling water.

[0011] As a further improvement of the above technical solution: the guide members are provided in plurality and distributed along the flow direction of the cooling water.

[0012] As a further improvement of the above technical solution: the heights of the two ends of at least one of the guide members are greater than the height of the middle portion and there is the gap between the middle portion and the heat dissipation substrate.

[0013] As a further improvement of the above technical solution: along the flow direction of the cooling water, the height and / or width of the guide member gradually increases.

[0014] As a further improvement of the above technical solution: positioning members are provided at both ends of the flow guide member, the positioning members are arranged vertically to the flow guide member, a positioning portion is provided on the cooling shell, and both ends of the positioning member abut against the positioning portion.

[0015] As a further improvement of the above technical solution: the guide member and the positioning member are integrally formed by plastic injection molding; or, the guide member and the positioning member are integrally formed by aluminum stamping.

[0016] A power module comprises a power chip and a packaging structure, and also comprises the above-mentioned water-cooling heat dissipation structure, wherein the packaging structure is arranged on the heat dissipation substrate.

[0017] Compared with the prior art, the advantages of the present invention are as follows: the water-cooled heat dissipation structure disclosed in the present invention deflects and guides the cooling flow channel through an additional structural guide member without changing the density of the heat dissipation pin fins on the heat dissipation substrate. On the one hand, the suddenly reduced flow cross-sectional area between the guide member and the heat dissipation substrate forces the continuously flowing cooling medium to accelerate, and the increase in flow rate can improve the heat exchange performance of the heat dissipation pin fins; on the other hand, the suddenly raised flow cross-sectional area forces the low-temperature cooling medium in the bottom area of ​​the heat dissipation pin fins to be raised and mixed with the high-temperature cooling medium near the heat dissipation substrate, greatly reducing the maximum temperature of the cooling medium near the heat dissipation substrate, eliminating the negative impact of the large temperature rise of the cooling medium near the heat dissipation substrate along the flow direction, and improving the heat exchange efficiency, thereby strengthening the heat dissipation of the local area of ​​the heat dissipation substrate, and the guide member is provided with a plug hole for the heat dissipation pin fin to be inserted, which is conducive to avoiding affecting the upstream packaging process and original structure of the power device. The water-cooled heat dissipation structure disclosed in the present invention has a simple overall structure and low cost. Compared with the existing method, it has a higher upper limit of heat dissipation performance and better flow resistance performance.

[0018] The power module disclosed in the present invention includes the above-mentioned water-cooling heat dissipation structure and thus also has the above-mentioned advantages; the guide member can be arranged corresponding to each power chip, thereby enhancing the heat exchange efficiency between the coolant and the high-temperature chip area, especially the over-temperature chip area, reducing the junction temperature of the power chip, and effectively improving the reliability and service life of the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention in a partial perspective state.

[0021] Figure 3 It is a schematic cross-sectional structure diagram of the outlet side of the cooling shell of the present invention.

[0022] Figure 4 It is a schematic diagram of the three-dimensional structure of the guide member and the positioning member in the present invention.

[0023] The numbers in the figure represent: 1. cooling shell; 11. flow channel inlet; 12. flow channel outlet; 2. heat dissipation substrate; 21. heat dissipation pin fins; 3. flow guide; 31. socket; 4. positioning member; 5. power chip; 6. packaging structure. DETAILED DESCRIPTION

[0024] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] In this application, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Embodiment 1

[0029] Figures 1 to 4 An embodiment of the water-cooled heat dissipation structure of the present invention is shown. The water-cooled heat dissipation structure of this embodiment includes a cooling shell 1 and a heat dissipation substrate 2 arranged on the cooling shell 1. A cooling channel is arranged inside the cooling shell 1. A plurality of heat dissipation pin fins 21 are arranged on the heat dissipation substrate 2 and extend into the cooling channel. A guide member 3 is arranged in the cooling channel. The guide member 3 and the heat dissipation substrate 2 are arranged on both sides of the cooling shell 1 opposite to each other. The guide member 3 is provided with a socket 31 for inserting the heat dissipation pin fin 21. For details, see Figure 1 In this embodiment, the main body of the cooling shell 1 is a rectangular plate-shaped structure and is hollow inside to form a cooling channel. A channel inlet 11 is provided on the left side of the cooling shell 1, and a channel outlet 12 is provided on the opposite right side. The coolant enters the cooling channel from the channel inlet 11, then flows to the right and flows out from the channel outlet 12, that is, the flow direction of the coolant in this embodiment is from left to right; preferably, the shape of the heat dissipation pin fin 21 can be cylindrical, prismatic, elliptical or square, irregular columnar, etc., and the socket 31 is adapted to the heat dissipation pin fin 21 to form a tight fit.

[0030] The water-cooled heat dissipation structure of this embodiment, without changing the density of the heat dissipation pin fins 21 on the heat dissipation substrate 2, deflects and guides the cooling flow channel through an additional structural guide member 3. On the one hand, the suddenly reduced flow cross-sectional area between the guide member 3 and the heat dissipation substrate 2 forces the continuously flowing cooling medium to accelerate, and the increase in flow rate can improve the heat exchange performance of the heat dissipation pin fins 21; on the other hand, the suddenly raised flow cross-section forces the low-temperature cooling medium in the terminal area of ​​the heat dissipation pin fins 21 to be raised and mixed with the high-temperature cooling medium near the heat dissipation substrate 2, which greatly reduces the maximum temperature of the cooling medium near the heat dissipation substrate 2, eliminates the negative impact caused by the significant temperature increase of the cooling medium near the heat dissipation substrate 2 along the flow direction, and improves the heat exchange efficiency, thereby enhancing the heat dissipation of the local area of ​​the heat dissipation substrate 2, and the guide member 3 is provided with a socket 31 for the heat dissipation pin fins 21 to be inserted, which is beneficial to avoid affecting the upstream packaging process and original structure of the power device. The water-cooled heat dissipation structure of this embodiment has a simple overall structure and low cost. Compared with the existing method, it has a higher upper limit of heat dissipation performance and better flow resistance performance (the better the enhanced heat dissipation effect of the guide member 3, the greater the flow resistance of the cooling channel will be. The heat dissipation performance and flow resistance can be balanced according to needs through CFD simulation during the design stage).

[0031] Furthermore, in the present embodiment, the heat dissipation substrate 2 is arranged on the upper part of the cooling shell 1, and the guide member 3 is connected to the lower part of the cooling shell 1. There is a gap between the heat dissipation substrate 2 and the guide member 3, specifically, there is a gap between the lower surface of the heat dissipation substrate 2 and the upper surface of the guide member 3, and the coolant can flow through the gap. The suddenly reduced flow cross-sectional area forces the continuously flowing cooling medium to accelerate, and the increase in flow rate can improve the heat exchange performance of the heat dissipation pin fins 21; the suddenly raised flow cross-section forces the low-temperature cooling medium in the bottom area of ​​the heat dissipation pin fins 21 to be raised and mixed with the high-temperature cooling medium near the heat dissipation substrate 2, thereby greatly reducing the maximum temperature of the cooling medium near the heat dissipation substrate 2, and eliminating the negative impact of the substantial temperature increase of the cooling medium near the heat dissipation substrate 2 along the flow direction, thereby enhancing the heat exchange effect with the heat dissipation pin fins 21, with a simple structure and a reasonable layout.

[0032] Furthermore, in this embodiment, the insertion hole 31 is a through hole, and the lower end of the heat dissipation pin fin 21 inserted into the insertion hole 31 abuts against the lower part of the cooling housing 1. The insertion hole 31 is a through hole, which facilitates the normal assembly and positioning of the lower end of the heat dissipation pin fin 21 with the lower part of the cooling housing 1, avoiding affecting the upstream packaging process and original structure of the power device. Preferably, the heat dissipation pin fin 21 is tightly matched with the insertion hole 31, so that the guide member 3 and the heat dissipation substrate 2 are tightly assembled.

[0033] As a preferred embodiment, the upper portion of the flow guide 3 is an inclined surface structure and the height of the inclined surface gradually increases along the flow direction of the cooling water, that is, the height of the upper surface of the flow guide 3 gradually increases from left to right, so that the flow cross-sectional area gradually decreases, and the low-temperature cooling medium and the high-temperature cooling medium are mixed more fully, which helps the flow guide 3 to better play the role of enhancing the heat dissipation effect. Of course, in other embodiments, the upper surface of the flow guide 3 can also be a plane structure, a step structure, a curved surface or an irregular shaped surface.

[0034] Furthermore, in this embodiment, three flow guides 3 are provided and distributed along the flow direction of the cooling water. Multiple flow guides 3 can respectively enhance the heat dissipation of different regions of the heat dissipation substrate 2 to different degrees, eliminate the adverse effects of the coolant temperature difference between the outlet and inlet sides of the conventional cooling channel, and ensure that the temperature of each region of the heat dissipation substrate 2 is basically the same. Of course, in other embodiments, the number of flow guides 3 can also be appropriately adjusted, and the specific layout number and position can be flexibly designed according to the position and number of the over-temperature heat source, which will not be repeated.

[0035] Among them, along the flow direction of the cooling water, the height, inclination of the upper surface, and / or width of the guide 3 gradually increase. During the flow of the coolant, due to the continuous convection heat exchange with the heat dissipation pin fins 21, the temperature gradually rises from the inlet to the outlet, and the junction temperature of the power chip 5 on the outlet side is the highest. By gradually increasing the height (vertical dimension of the guide 3), the inclination of the upper surface, and / or the width (the dimension of the guide 3 in the left and right directions), the heat exchange efficiency is gradually increased (the heat exchange efficiency of the power chip 5 on the outlet side in this embodiment is about 150% of the heat exchange efficiency of the power chip 5 on the inlet side), thereby achieving the purpose of temperature equalization. According to CFD simulation evaluation, under the same chip loss and heat dissipation boundary conditions, after adopting the water-cooled heat dissipation structure of the present invention, the maximum junction temperature of the power chip 5 on the inlet side drops by about 3°C, and the maximum junction temperature of the power chip 5 on the outlet side drops by about 18°C, and the temperature difference between the two does not exceed 1°C, and the temperature equalization effect is obvious and excellent.

[0036] Furthermore, in this embodiment, the heights of the two ends of the two downstream flow guides 3 are greater than the height of the middle part, and there is a gap between the middle part and the heat dissipation substrate 2. The flow section suddenly concentrates toward the middle part, so that the continuously flowing cooling medium is forced to concentrate in the middle area corresponding to the high-temperature chip (or other heat source), and the low-temperature cooling medium in the edge area of ​​the heat dissipation substrate 2 is transferred to the middle high-temperature chip area, further reducing the average temperature of the cooling medium in the middle, and fully utilizing the heat dissipation performance of the full-flow cooling medium, so as to achieve the purpose of locally strengthening the heat dissipation of the heat dissipation substrate 2.

[0037] Furthermore, in this embodiment, positioning members 4 are provided at both ends of the flow guide 3, and the positioning members 4 are arranged vertically with the flow guide 3. A positioning portion is provided on the cooling shell 1, and both ends of the positioning member 4 abut against the positioning portion. The positioning members 4 can connect the distributed flow guides 3 into a whole, so as to achieve one-time positioning and assembly, which has a simple and reliable structure, ensures mechanical strength, and does not affect the upstream packaging process and original structure of the power device; the assembly and positioning of the flow guide 3 in the cooling shell 1 is completed with the help of the positioning portion on the cooling shell 1, which is easy to operate, has good assembly stability and is easy to disassemble. Preferably, the positioning member 4 adopts a thin rib structure.

[0038] Preferably, the guide member 3 and the positioning member 4 can be integrally formed by plastic injection molding; or, the guide member 3 and the positioning member 4 can also be integrally formed by aluminum stamping, which has a simple and reliable structure, high mechanical strength, easy processing and manufacturing, and low cost.

[0039] Embodiment 2

[0040] Figures 1 to 4 An embodiment of a power module of the present invention is shown. The power module of this embodiment includes a power chip 5 and a packaging structure 6 , and also includes the above-mentioned water-cooling heat dissipation structure. The packaging structure 6 is arranged on a heat dissipation substrate 2 .

[0041] The power module of this embodiment includes the above-mentioned water-cooling heat dissipation structure and thus also has the above-mentioned advantages; the flow guide 3 can be arranged corresponding to each power chip 5, thereby enhancing the heat exchange efficiency between the coolant and the high-temperature chip area, especially the over-temperature chip area, reducing the junction temperature of the power chip 5, and effectively improving the reliability and service life of the power module.

[0042] For a commonly used specification six-unit IGBT module with a limited output current working condition, the junction temperature of the chip on the water outlet side of the prior art has reached 150°C (the example module's limited application temperature), and the junction temperature of the chip on the water inlet side is only 137.2°C. By adopting the technical solution of the present invention, the maximum junction temperature of the chip on the water inlet side is reduced by about 3°C, the maximum junction temperature of the chip on the water outlet side is reduced by about 15°C, and the overall maximum junction temperature of the IGBT chip is reduced by 15°C. The maximum output current of the IGBT is thereby increased by about 20% (500A→600A), and the maximum junction temperature difference between phases is reduced from 12.8°C to 0.8°C, eliminating the shortcoming of the temperature difference of the IGBT chip. While improving the module's maximum output capacity, the service life of the module is also increased by more than 2 times under the same working conditions (usually, for every 10°C increase in the maximum junction temperature, the device service life is reduced by about half).

[0043] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A water-cooled heat dissipation structure, comprising a cooling shell (1) and a heat dissipation substrate (2) arranged on the cooling shell (1), wherein a cooling channel is arranged inside the cooling shell (1), and a plurality of heat dissipation pin fins (21) are arranged on the heat dissipation substrate (2) and extend into the cooling channel, characterized in that: A flow guide (3) is provided in the cooling flow channel. The flow guide (3) and the heat dissipation substrate (2) are arranged on two sides of the cooling shell (1) opposite to each other. The flow guide (3) is provided with a plug hole (31) for inserting the heat dissipation pin fin (21).

2. The water cooling heat dissipation structure according to claim 1, characterized in that: The heat dissipation substrate (2) is arranged on the upper part of the cooling shell (1), the flow guide (3) is connected to the lower part of the cooling shell (1), and there is a gap between the heat dissipation substrate (2) and the flow guide (3).

3. The water cooling heat dissipation structure according to claim 2, characterized in that: The insertion hole (31) is a through hole, and the lower end of the heat dissipation pin fin (21) inserted into the insertion hole (31) abuts against the lower part of the cooling shell (1).

4. The water cooling heat dissipation structure according to claim 2, characterized in that: The upper part of the flow guide (3) is a slope structure, and the height of the slope gradually increases along the flow direction of the cooling water.

5. The water cooling and heat dissipation structure according to any one of claims 2 to 4, characterized in that: The flow guide members (3) are provided in plurality and distributed along the flow direction of the cooling water.

6. The water cooling heat dissipation structure according to claim 5, characterized in that: The heights of the two ends of at least one of the guide members (3) are greater than the height of the middle portion, and there is the gap between the middle portion and the heat dissipation substrate (2).

7. The water cooling heat dissipation structure according to claim 5, characterized in that: Along the flow direction of the cooling water, the height and / or width of the flow guide (3) gradually increases.

8. The water cooling and heat dissipation structure according to any one of claims 1 to 4, characterized in that: Positioning members (4) are provided at both ends of the flow guide member (3), the positioning members (4) are arranged vertically to the flow guide member (3), a positioning portion is provided on the cooling shell (1), and both ends of the positioning member (4) abut against the positioning portion.

9. The water cooling and heat dissipation structure according to claim 8, characterized in that: The flow guide (3) and the positioning member (4) are integrally formed by plastic injection molding; or, the flow guide (3) and the positioning member (4) are integrally formed by aluminum stamping molding.

10. A power module, comprising a power chip (5) and a packaging structure (6), characterized in that: It also comprises the water-cooled heat dissipation structure according to any one of claims 1 to 9, wherein the packaging structure (6) is arranged on the heat dissipation substrate (2).

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