Radiator

Abstract

The utility model provides a radiator which comprises a cold plate, the cold plate is provided with a first face making contact with a device to be cooled and a second face opposite to the first face, a fluid inlet is formed in the middle of the second face, fluid outlets with the same number are formed in the two sides of the fluid inlet respectively, a cavity is formed in the cold plate, and the fluid outlets are communicated with the cavity. The cavity is respectively communicated with the fluid inlet and the fluid outlet, and a micro-channel fin area is arranged in the cavity. According to the radiator, the fluid inlet is formed in the middle of the second face of the cold plate, the fluid outlets with the same number are formed in the two sides of the fluid inlet correspondingly, the coldest fluid entering from the fluid inlet cools the hottest heat source position, namely the middle heat source position preferentially, and therefore the junction temperature of an electronic device can be reduced; the problem of overheating concentration of an electronic device can be solved, so that the temperature uniformity is improved.

Description

Technical Field

[0001] The present application relates to the technical field of heat dissipation equipment, and in particular to a heat sink. Background Art

[0002] As a type of liquid cooling technology, cold plate liquid cooling technology has the advantages of high heat dissipation efficiency, good stability and reliability, compactness and lightness, energy saving, etc. At the same time, electronic devices will not have direct contact with the coolant. At present, the technical maturity of cold plate liquid cooling technology is relatively high. Especially after combining it with microchannel enhanced heat exchange technology, the heat dissipation performance is further improved. Therefore, it is used in military radars, high-density data centers, high-performance computers, power batteries, high-power LEDs and other heat dissipation fields. It is an effective application solution to solve high-power and high-heat flow heat dissipation, improve energy efficiency, reduce refrigeration operation costs, and improve stability and reliability.

[0003] In the process of implementing the present invention, the inventors found that there are at least the following technical problems in the prior art:

[0004] At present, as the heat flux density of electronic devices gradually increases, and some electronic devices have the problem of heat concentration in the center of the device, when the existing cold plate liquid cooling device dissipates heat for electronic devices with the above problems, because the heat dissipation device and the electronic device are installed in a covering manner and the working fluid inlet of the heat dissipation device is set near its edge, it is impossible to effectively dissipate heat at the place where heat is concentrated, and the heat dissipation effect is poor, which will affect the stability and service life of the entire device. Summary of the invention

[0005] In view of this, the present application proposes a heat sink that can solve the problem of overheating concentration of electronic devices and improve the heat dissipation effect of electronic devices.

[0006] To achieve the above objectives, the present application provides a heat sink, comprising a cold plate, wherein the cold plate has a first surface in contact with a device to be cooled and a second surface arranged opposite to the first surface, the second surface is provided with a fluid inlet, wherein a plurality of fluid outlets are symmetrically arranged on the second surface with the fluid inlet as the center, and a cavity is provided inside the cold plate, and the cavity is respectively connected to the fluid inlet and the fluid outlet.

[0007] In one embodiment, the cavity of the cold plate includes an inlet buffer cavity, a throttling structure, a microchannel fin area and an outlet buffer cavity in sequence from the fluid flow direction; the upper end of the inlet buffer cavity is connected to the fluid inlet, and the lower end is connected to the throttling structure, and a microchannel fin area is arranged in the cavity.

[0008] In one embodiment, the throttling structure is arranged below the inlet buffer cavity; the length of the throttling structure is consistent with the length of the inlet buffer cavity, and the width is smaller than the width of the inlet buffer cavity, or the width of the upper end of the throttling structure is consistent with the width of the inlet buffer cavity, and the width of the lower end is smaller than the width of the upper end.

[0009] In one embodiment, the upper end of the inlet buffer cavity is communicated with the fluid inlet, and the lower end is communicated with the upper end of the throttling structure; the width of the inlet buffer cavity covers the width of the microchannel fin area.

[0010] In one embodiment, the upper end of the outlet buffer cavity is connected to the fluid outlet, and one side of the outlet buffer cavity is connected to the microchannel fin area; the outlet buffer cavity is in a shape with equal width or a shape with contracted width along the fluid flow direction.

[0011] In one embodiment, the microchannel fin area is provided with multiple rows of fin groups at intervals in the direction of fluid flow; in each row of fin groups, a plurality of pin-fins are arranged at intervals, and tiny channels are formed between adjacent pin-fins; the pin-fins in each row of fin groups are staggered with the pin-fins in the next row of fin groups in the direction of fluid flow.

[0012] In one embodiment, the pin wing is in a shape of a larger lower portion and a smaller upper portion.

[0013] In one embodiment, the heights of the pin fins and the microchannels in the microchannel fin area gradually increase along the fluid flow direction.

[0014] In one embodiment, the top surfaces of all the pin fins are connected to the top surface a, the bottom surfaces of all the pin fins are connected to the bottom surface b, the bottom surface b is parallel to the bottom surface of the cold plate, and the top surface a is inclined to the bottom surface b.

[0015] In one embodiment, the diameter of the fluid outlet is larger than the diameter of the fluid inlet, and the heat sink is an integrally formed structure.

[0016] The heat sink provided by the present application has the following beneficial effects: when the heat sink is mounted on the electronic device to be cooled, since the fluid inlet of the heat sink of the present application is arranged in the middle of the second surface of the cold plate, and an equal number of fluid outlets are symmetrically arranged on both sides of the fluid inlet, at this time, the position of the fluid inlet corresponds to the center position of the electronic device, so the coldest fluid entering from the fluid inlet preferentially cools the center position of the electronic device with the highest temperature, thereby helping to reduce the temperature at the center position of the electronic device and solve the problem of overheating concentration of the electronic device; in addition, the fluid path design of middle inlet and two-side outlet can make the effective flow of the fluid relatively shorter than the design of single-side inlet and single-side outlet, which is more conducive to reducing the surface temperature difference of the radiator and improving temperature uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the three-dimensional structure of a radiator provided in one embodiment of the present application;

[0018] Figure 2 for Figure 1 A perspective structural diagram of a radiator in FIG.

[0019] Figure 3 The heat sink of one embodiment of the present application is Figure 2 Schematic diagram of the cross-sectional structure in the AA direction;

[0020] Figure 4 for Figure 3 A magnified view of part I;

[0021] Figure 5 For along Figure 2 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0022] Figure 6 for Figure 5 Enlarged view of part II;

[0023] Figure 7 For along Figure 2 Schematic diagram of the cross-sectional structure in the CC direction;

[0024] Figure 8 Another embodiment of the present invention is a heat sink. Figure 2 Schematic diagram of the cross-sectional structure in the AA direction.

[0025] The components in the figure are labeled as follows:

[0026] Radiator 100;

[0027] Fluid inlet 110; fluid outlet 120; cold plate 130;

[0028] Inlet buffer chamber 131 ; throttling structure 132 ; microchannel fin area 133 (including pin fins 1331 , tiny channels 1332 ; top surface a, bottom surface b); outlet buffer chamber 134 . DETAILED DESCRIPTION

[0029] Before describing the embodiments in detail, it should be understood that the present application is not limited to the detailed structure or component arrangement described below or in the drawings in the present application. The present application may be an embodiment implemented in other ways. Moreover, it should be understood that the words and terms used herein are only used for descriptive purposes and should not be interpreted restrictively. The words "including", "comprising", "having" and the like used herein are meant to include the items listed thereafter, their equivalents and other additional items. In particular, when describing "a certain element", the present application does not limit the number of the element to one, but may also include multiple elements.

[0030] In response to the problems existing in the prior art pointed out in the above background technology, the heat sink of the present application can cool electronic devices with high heat flux density, achieve efficient heat dissipation while meeting the requirements of temperature control, enhance flow stability while improving the temperature uniformity of the electronic devices, thereby ensuring the overall performance of the electronic devices.

[0031] See also Figure 1 and Figure 2 , the heat sink 100 includes a fluid inlet 110, a fluid outlet 120 and a cold plate 130, and the cold plate 130 has a first surface in contact with the device to be cooled and a second surface arranged opposite to the first surface. In the illustrated embodiment, the fluid inlet 110 and the fluid outlet 120 are connected to the top surface of the cold plate 130 (the second surface, the cold plate cover side), and the bottom surface of the cold plate 130 (the first surface, the cold plate substrate side) is the contact surface with the electronic device with high heat flux density. In the heat sink 100, the fluid enters the cold plate 30 from the top of the cold plate 30 and then flows out from the fluid outlet 120 at the top of the cold plate 30. The fluid enters and exits from the top, which has a certain diversion effect. The heat sink 100 can adopt metal 3D printing integrated molding technology, and each part of the structure is integrally molded, without secondary processing such as welding, so that the structure is more solid and reliable. The surface roughness of the structure of the heat sink 100 produced by 3D printing is relatively large. For two-phase cold plate liquid cooling, the number of vaporization cores is increased, the heat dissipation and heat exchange capacity and the temperature uniformity effect are improved, and it is beneficial to the internal flow boiling stability.

[0032] More specifically, the fluid inlet 110 is arranged in the middle of the top surface of the cold plate 130 (the cold plate cover side). In order to enable the heat sink to be integrally formed by metal 3D printing, two fluid outlets 120 are designed, and the two fluid outlets 120 are symmetrically arranged on both sides of the fluid inlet 110. It should be pointed out that the arrangement of two fluid outlets 120 in the illustrated embodiment is a preferred embodiment. In principle, the number of fluid outlets 120 on the cold plate 130 can be set to a larger even number, and the arrangement of the same number of fluid outlets 120 on both sides of the fluid inlet (110) is within the scope of the present application.

[0033] The fluid inlet and fluid outlet of the heat sink 100 are designed in this way, and the reasons are mainly the following two aspects: due to the heat concentration of the heat source, the middle position of the heat source is prone to high temperature. The fluid path design of the middle inlet and the two-side outlet makes the coldest fluid preferentially cool the hottest heat source position, that is, the middle heat source, which is beneficial to reduce the junction temperature of the electronic device; in addition, compared with the design of single-side inlet and single-side outlet, the fluid path design of the middle inlet and the two-side outlet can make the effective flow of the fluid relatively shorter, which is more conducive to reducing the surface temperature difference of the heat sink and improving the temperature uniformity. In the illustrated embodiment, on the heat sink 100, the fluid inlet 110 and the fluid outlet 120 are cylindrical, and the diameter of the fluid outlet 120 is larger than the diameter of the fluid inlet 110. For two-phase cold plate liquid cooling, the diameter of the fluid inlet 110 is smaller than the diameter of the fluid outlet 120, which can make it easier for the refrigerant working medium to flow out from the outlet after absorbing heat and undergoing phase change from liquid to gas, thereby reducing the risk of gas reflux.

[0034] Please refer to Figure 3 and Figure 4 , which is a schematic diagram of a vertical flow channel cross section of the heat sink 100. A cavity is formed inside the cold plate 130 for the fluid to flow from the fluid inlet 110 to the fluid outlet 120. From the fluid flow direction (as shown by the arrow in the figure), the cold plate 130 includes an inlet buffer cavity 131, a throttling structure 132, a microchannel fin area 133 and an outlet buffer cavity 134 in sequence. The fluid entering the cold plate 130 from the fluid inlet 110 first flows from top to bottom into the fluid inlet buffer cavity 131, and the fluid passing through the inlet buffer cavity 131 flows from top to bottom through the throttling structure 132 and then flows to both sides into the microchannel fin area 133. The fluid flowing out of the microchannel fin area 133 flows outward through the outlet buffer cavity 134, and the fluid finally flows out from the fluid outlet 120 from bottom to top.

[0035] The upper end of the inlet buffer chamber 131 is connected to the fluid inlet 110, and the lower end is connected to the upper end of the throttling structure 132. In the illustrated embodiment, the inlet buffer chamber 131 is a rectangular parallelepiped, and the width of the inlet buffer chamber 131 covers the width of the entire microchannel fin area 133. In other embodiments, the shape of the inlet buffer chamber 131 is not limited to a rectangular parallelepiped, and can also be other shapes such as a quadrangular prism, a pentagonal prism, etc.

[0036] The upper end of the throttling structure 132 is connected to the inlet buffer chamber 131, and the lower end is connected to the microchannel fin area 133. Figure 3 In the embodiment shown, the throttling structure 132 is a rectangular parallelepiped, and the length of the throttling structure 132 is consistent with the length of the inlet buffer cavity 131, but the width thereof is smaller than the width of the inlet buffer cavity 131. Figure 8As shown in , the throttling structure 132 may also be in the form of a quadrangular prism (trapezoid), the width of the upper end is consistent with the width of the inlet buffer chamber 131, and the width of the lower end is smaller than the width of the upper end. That is, the cross-sectional area of ​​the throttling structure 132 and the microchannel fin area 133 perpendicular to the fluid flow direction is smaller than the cross-sectional area of ​​the inlet buffer chamber 131 perpendicular to the fluid flow direction, so as to throttle the fluid passing through.

[0037] The throttling structure 132 is arranged between the inlet buffer cavity 131 and the microchannel fin area 133, which can bring at least the following effects: the fluid enters the inlet buffer cavity 131 from the fluid inlet 110. Since the size of the throttling structure 132 is smaller than the size of the inlet buffer cavity 131, the fluid is preferentially filled horizontally, quickly fills the inlet buffer cavity 131, and then flows into the microchannel fin area 133, thereby improving the uniformity of fluid distribution. In addition, the design that the size of the throttling structure 132 is smaller than the size of the inlet buffer cavity 131 forms a jet at the center position, increases the local flow velocity of the fluid, improves the heat transfer coefficient at the center position, and is conducive to strengthening heat exchange; at the same time, for two-phase cold plate liquid cooling, the design that the size of the throttling structure 132 is smaller than the size of the inlet buffer cavity 131 increases the resistance of the gas generated by vaporization to flow back through the throttling structure 132 under the action of gravity and buoyancy, which is conducive to suppressing flow instability.

[0038] The upper end of the outlet buffer chamber 134 is connected to the fluid outlet 120, and one side of the outlet buffer chamber 134 is connected to the microchannel fin area 133. Figure 3 In the embodiment shown, the outlet buffer cavity 134 is a rectangular parallelepiped with equal widths at the top and bottom. Figure 8 As shown in , the outlet buffer chamber 134 is in a shape whose width shrinks from bottom to top (in the direction of fluid flow), and the outlet buffer chamber 134 slowly shrinks and connects with the fluid outlet 120, so that the fluid can flow out better and reduce the flow resistance, which is also more conducive to improving the flow stability for two-phase cold plate liquid cooling.

[0039] Please refer to Figures 5 to 7 In the microchannel fin area 133, the fin array is arranged, and the fluid passes between the fins. More specifically, the fins in the microchannel fin area 133 are pin fins 1331 and are arranged in staggered rows, thereby forming microchannels 1332 that are staggered in the direction of fluid flow. The microchannel fin area 133 is provided with multiple rows of fin groups at intervals in the direction of fluid flow; in each row of fin groups, the pin fins 1331 are arranged at intervals, and microchannels 1332 are formed between adjacent pin fins 1331; the pin fins 1331 of each row of fin groups are staggered with the pin fins 1331 of the next row of fin groups in the direction of fluid flow, see Figure 7 .

[0040] The fins in the existing heat sinks are mostly straight fins, and each fin is independent of each other in the flow channel, that is, the liquid does not mix with each other after entering the fin channel. Since the heat sink structure is relatively simple, the heat dissipation capacity is relatively low, which is not conducive to the control of the junction temperature; in addition, the independent straight fin structure causes the fluid temperature to gradually increase along the flow channel direction. If the uniformity of fluid distribution in each channel is not considered, it is seriously detrimental to the temperature uniformity of the electronic device. In the heat sink 100, the microchannel fin area 133 adopts staggered pin fins 1331, which can bring the following effects: compared with the straight channel, the pin fin design not only makes the flow channels interconnected, but also improves the flow stability, especially for two-phase cold plate liquid cooling, avoiding the flow instability caused by pressure imbalance in the channel, and the staggered pin fins strengthen the fluid turbulence, thereby enhancing the heat exchange, which is beneficial to improve the heat dissipation performance of the heat sink.

[0041] like Figure 5 and Figure 6 As shown in , the pin fin 1331 is designed to be in a truncated cone shape. In the cross section perpendicular to the fluid flow direction, the truncated cone-shaped pin fin 1331 is in a trapezoidal structure, wherein the long side of the trapezoid is on the cold plate substrate side, i.e., the side close to the heat source, and the short side of the trapezoid is on the cold plate cover side, i.e., the side close to the fluid inlet and outlet, and is in a shape of a large lower part and a small upper part. As a result, the micro-channel 1332 formed by the gap between the pin fins 1331 also has a trapezoidal shape in cross section, but correspondingly, the short side of the trapezoid of the cross section of the micro-channel 1332 is on the radiator substrate side, i.e., the side close to the heat source, and the long side of the trapezoid is on the radiator cover side, i.e., the side close to the inlet and outlet.

[0042] The microchannel fin area 133 is designed in such a way that the thickness of the pin fin 1331 gradually decreases and the width of the microchannel 1332 gradually increases from bottom to top along the vertical fluid flow direction, so that the flow velocity at the bottom is fast and the flow velocity at the top is slow, which is beneficial to strengthen the heat exchange at the contact position with the substrate and reduce the radiator temperature. In particular, for two-phase cold plate liquid cooling, under the influence of gravity and buoyancy, the ease of bubble growth and separation in the radial direction gradually increases, and it is easier to move upward, promoting vapor-liquid separation, which is beneficial to boiling heat exchange, reducing local drying phenomenon, and improving flow stability.

[0043] See also Figure 3 and Figure 4 , the heights of the pin fins 1331 and the microchannels 1332 in the microchannel fin area 133 gradually increase along the fluid flow direction. Figure 4As shown, the top surface a of the microchannel fin area 133 is inclined to the bottom surface b, and the distance between the top surface a and the bottom surface b gradually increases in the direction of fluid flow. The top surfaces of all pin fins 1331 are in the same plane - the top surface a, and the bottom surfaces are in the same plane - the bottom surface b, and the bottom surface b is parallel to the bottom surface of the cold plate 130; but in the direction perpendicular to the fluid flow, the top surface of the pin fin 1331 is inclined, and the top surface of the pin fin 1331 is connected to the cold plate cover. From the middle position of the radiator to both sides, that is, from the inlet to the outlet, the height of each pin fin 1331 and the microchannel 1332 increases toward the top at a certain slope, and the top surface a forms an upwardly inclined slope.

[0044] The design of the microchannel fin area 133 can bring the following effects: along the direction of fluid flow, the cross-section of the circumferential channel gradually increases, the flow velocity in the middle of the microchannel fin area 133 is the largest, and the flow velocity is slower as it approaches the outlet, thereby enhancing the heat exchange in the middle, which is beneficial to reducing the junction temperature of the radiator and improving temperature uniformity. In particular, the cross-section of the circumferential channel gradually increases, and for two-phase cold plate liquid cooling, the ease with which bubbles grow radially gradually increases, and bubbles easily move toward the outlet side after detaching; in addition, affected by gravity and buoyancy, bubbles grow and detach and move upward under the influence of buoyancy, and the inclined design at the top is beneficial to the movement of bubbles toward the outlet. Therefore, the inclined design in the vertical direction further weakens the piston effect, which is beneficial to eliminating bubble blockage and liquid reflux.

[0045] During operation, heat is transferred to the inner surface of the radiator 100 through heat conduction. The operation process of the working medium in the radiator 100 is as follows: under the action of an external driving force, the low-temperature liquid working medium enters the inlet buffer chamber 131 from top to bottom from the fluid inlet 110, is buffered by the inlet buffer chamber 131, and then is throttled by the throttling structure 132 and diverted to both sides to flow into the microchannel fin area 133; the working medium flows in the microchannel fin area 133.

[0046] During the flow in the microchannel fin area 133, the phase change process of the working medium is as follows:

[0047] Alternatively, during the process, the temperature of the working medium that absorbs heat increases, and the high-temperature liquid working medium, driven by the pressure difference, flows out from the fluid outlet 120 from bottom to top through the outlet buffer chamber 134 to complete the heat exchange (single-phase cold plate liquid cooling);

[0048] Alternatively, the working fluid that absorbs heat boils and generates a large number of bubbles to form a two-phase flow. Driven by the pressure difference, the vapor-liquid mixed working fluid flows from the bottom to the top through the outlet buffer chamber 134 and out of the fluid outlet 120 to complete the heat exchange (two-phase cold plate liquid cooling).

[0049] In summary, the present application provides a radiator with high heat flux density electronic devices arranged on the bottom surface. The radiator is versatile and can cool high heat flux density electronic devices. It can be used for single-phase cold plate liquid cooling and two-phase cold plate liquid cooling. At the same time, the radiator is manufactured using metal 3D printing one-piece molding technology, which not only reduces the use of splicing technologies such as welding and improves reliability, but also provides a large number of vaporization cores for two-phase cold plate liquid cooling, improves heat exchange capacity and temperature equalization effect, and is beneficial to internal flow boiling stability. Compared with the prior art, the radiator of the present application has at least the following advantages:

[0050] (1) The design of the working fluid entering from the middle of the cold plate and exiting from both sides is conducive to reducing the junction temperature at the center of the electronic device on the cold plate substrate side, reducing the temperature difference on the surface of the heat sink, and solving the problem of overheating concentration of the electronic device to achieve improved temperature uniformity.

[0051] (2) A throttling structure is provided below the inlet buffer cavity at the center of the cold plate, so that a jet is formed at the center, the local flow velocity of the fluid is increased, and the heat transfer coefficient at the center is improved, which is beneficial to enhancing heat exchange; at the same time, for two-phase cold plate liquid cooling, the resistance of the vapor generated by vaporization to flow back through the throttling structure under the action of gravity and buoyancy is increased, which is beneficial to suppressing flow instability.

[0052] (3) The fins in the microchannel fin area are designed as pin fins, which are arranged in a staggered manner, which is beneficial to enhancing fluid turbulence and heat transfer.

[0053] (4) The pin fins in the microchannel fin area are designed to be small at the top and large at the bottom, so that the microchannel ladder is small at the bottom and large at the top, resulting in a fast flow rate at the bottom and a slow flow rate at the top, which is beneficial to strengthening the heat exchange at the contact position with the substrate and reducing the radiator temperature. For two-phase cold plate liquid cooling, under the influence of gravity and buoyancy, the ease of bubble growth and detachment in the radial direction gradually increases, and it is easier to move upward, promoting vapor-liquid separation, which is beneficial to boiling heat exchange, reducing local drying phenomenon, and improving flow stability.

[0054] (5) Along the direction of fluid flow, the top of the pin fin is tilted. From the middle position of the cold plate to the two sides, that is, from the fluid inlet to the fluid outlet, the height of each pin fin and the micro-channel increases toward the top at a certain slope, forming an inclined slope, so that the microchannel fin area has the largest flow rate in the middle position of the cold plate, and the flow rate is slower as it approaches the fluid outlet, thereby enhancing the heat exchange in the middle position, which is beneficial to reducing the junction temperature of the radiator and improving temperature uniformity. In particular, the cross-section of the circumferential micro-channel gradually increases. For two-phase cold plate liquid cooling, the ease of bubble growth in the radial direction gradually increases, and the bubble is easy to move to the outlet side after detaching; in addition, affected by gravity and buoyancy, the bubble grows and detaches and moves upward under the influence of buoyancy. The tilted design of the top is conducive to the movement of the bubble to the outlet. Therefore, the tilted design in the vertical direction further weakens the piston effect, which is beneficial to eliminate bubble blockage and liquid reflux.

[0055] The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The specific embodiments disclosed should be considered illustrative rather than restrictive. Therefore, the scope of this application is determined by the appended claims rather than by the preceding description. Any changes within the literal meaning and equivalent scope of the claims should fall within the scope of these claims.

Claims

1. A radiator, characterized in that: The invention comprises a cold plate (130), wherein the cold plate (130) has a first surface in contact with a device to be cooled and a second surface arranged opposite to the first surface, wherein the second surface is provided with a fluid inlet (110), wherein a plurality of fluid outlets (120) are symmetrically arranged on the second surface with the fluid inlet (110) as the center, and a cavity is arranged inside the cold plate (130), wherein the cavity is respectively connected to the fluid inlet (110) and the fluid outlet (120).

2. The heat sink according to claim 1, characterized in that: The cavity of the cold plate (130) includes, in sequence from the fluid flow direction, an inlet buffer cavity (131), a throttling structure (132), a microchannel fin area (133) and an outlet buffer cavity (134); the upper end of the inlet buffer cavity (131) is connected to the fluid inlet (110), and the lower end is connected to the throttling structure (132).

3. The heat sink according to claim 2, characterized in that: The throttling structure (132) is arranged below the inlet buffer chamber (131); the length of the throttling structure (132) is consistent with the length of the inlet buffer chamber (131), and the width is smaller than the width of the inlet buffer chamber (131); or, the width of the upper end of the throttling structure (132) is consistent with the width of the inlet buffer chamber (131), and the width of the lower end is smaller than the width of the upper end.

4. The heat sink according to claim 2, characterized in that: The upper end of the inlet buffer chamber (131) is in communication with the fluid inlet (110), and the lower end is in communication with the upper end of the throttling structure (132); the width of the inlet buffer chamber (131) covers the width of the microchannel fin area (133).

5. The heat sink according to claim 2, characterized in that: The upper end of the outlet buffer cavity (134) is in communication with the fluid outlet (120), and one side of the outlet buffer cavity (134) is in communication with the microchannel fin area (133); the outlet buffer cavity (134) is in a shape with equal width or a shape with contracted width along the fluid flow direction.

6. The heat sink according to claim 2, characterized in that: The microchannel fin area (133) is provided with multiple rows of fin groups at intervals in the direction of fluid flow; in each row of fin groups, a plurality of pin fins (1331) are arranged at intervals, and tiny channels (1332) are formed between adjacent pin fins (1331); the pin fins (1331) in each row of fin groups are staggered with the pin fins (1331) in the next row of fin groups in the direction of fluid flow.

7. The heat sink according to claim 6, characterized in that: The pin wing (1331) is in a shape of a larger lower portion and a smaller upper portion.

8. The heat sink according to claim 6, characterized in that: The heights of the pin fins (1331) and the tiny channels (1332) in the microchannel fin area (133) gradually increase along the fluid flow direction.

9. The heat sink according to claim 6, characterized in that: The top surfaces of all the pin fins (1331) are connected to the top surface a, the bottom surfaces of all the pin fins (1331) are connected to the bottom surface b, the bottom surface b is parallel to the bottom surface of the cold plate (130), and the top surface a is inclined to the bottom surface b.

10. The radiator according to any one of claims 1 to 9, characterized in that: The caliber of the fluid outlet (120) is greater than the caliber of the fluid inlet (110), and the heat sink is an integrally formed structure.

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