Multi-layer gradient array jet flow micro-channel structure based on liquid metal

Abstract

The invention relates to a jet flow microchannel multilayer array gradient structure based on liquid metal. The temperature uniformity of heat dissipation of a jet flow radiator is mainly improved by using a multilayer gradient array structure. The structure comprises a fluid inlet and outlet, a fluid cavity, jet flow holes, cylindrical pin fins, rectangular fins and a ceramic substrate. The jet hole layer is provided with a dense jet hole gradient array, and the hole diameters of jet holes are gradually reduced from inside to outside. The jet hole layer adopts a gradient sunken design, so that the flow velocity of the jet holes in the edge zone of the radiator impacting the bottom can be improved, and the local heat exchange capability and temperature uniformity of the radiator can be improved. Liquid metal with good heat transfer performance is used as the fluid, and a ceramic material with high corrosion resistance is selected as the base plate. The cylindrical pin fin structure of the bottom flow layer also adopts gradient array arrangement, and the diameters of the pin fins are sequentially increased from inside to outside. The fins in the bottom layer flow area are also arranged in a gradient array mode, and the side lengths of the rectangular fins are larger and larger from inside to outside. By means of the design, liquid metal can form local vortexes when impacting the bottom, the impact strength and the heat transfer efficiency can be improved, meanwhile, the gradient array arrangement of the pin fins and the fins in the bottom heat exchange area can effectively improve the heat exchange efficiency of the edge zone of the radiator, and the overall heat dissipation temperature uniformity of the radiator can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of jet microchannel heat dissipation scheme, it is a kind of jet hole opening gradient array based on liquid metal and bottom with cylindrical gradient matrix needle fin and rectangular gradient array fin of jet microchannel heat dissipation scheme, can be used for the cooling of high heat generating equipment such as microwave chip, high-power device and laser. TECHNICAL BACKGROUND

[0002] With the rapid development of semiconductor technology, electronic equipment is increasingly towards the direction of high integration, high power density, high reliability and miniaturization. Chip size is continuously reduced, and power density is sharply increased, which poses a severe test on its thermal management capability. The heat flux of traditional integrated circuits is about 100 W / cm², and with the continuous improvement of chip performance and further miniaturization, the average heat flux is expected to climb to 500 W / cm², and the local hotspot heat flux may exceed 1000 W / cm². Excessive temperature on the chip surface can significantly affect its working efficiency and service life, and in severe cases, it can even cause thermal failure, leading to the device unable to operate normally. Therefore, how to achieve efficient heat dissipation of core devices has become a key issue to be tackled. Developing advanced cooling technology to effectively solve the chip surface heat transfer problem and ensuring its safe and efficient operation has very important practical significance.

[0003] In addition, high heat flux chips are often accompanied by significant temperature distribution problems, and local overheating can form "hot spots", which seriously affect the stability and reliability of the chip. To improve this phenomenon, the new heat dissipation structure needs to consider the improvement of overall heat dissipation efficiency and temperature uniformity. By designing a reasonable layout and needle fin and rib array in the jet impact area, the flow of cooling medium can be promoted, and heat can be quickly spread and redistributed on the chip surface. At the same time, optimizing the size distribution of jet holes can make the cooling medium more evenly cover the heat source area, and improve the local hotspot problem. The heat sink structure enhances the uniformity of vortex and heat exchange in the bottom area, not only improves the overall heat transfer capacity, but also helps to reduce the maximum temperature and average temperature on the chip surface, thereby providing a stable and uniform thermal environment for high-power electronic equipment, further ensuring the service life of electronic components.

[0004] Among numerous emerging cooling solutions, jet microchannel impingement cooling technology has attracted significant attention and is considered one of the most promising directions for improving heat transfer in high-performance electronic chips. This technology integrates the heat dissipation principles of microchannels and jets. The working fluid directly impacts the bottom of the microchannel through a nozzle, forming an extremely thin boundary layer on the heated surface, generating a strong convective heat transfer effect, thus significantly enhancing heat transfer. Therefore, jet microchannel cooling technology is particularly suitable for the heat dissipation needs of high heat flux and high-power chips. Meanwhile, room-temperature liquid metal convection cooling technology has also proven to be an effective means of addressing the challenges of high heat flux density heat dissipation. To this end, this paper proposes a jet microchannel heat sink structure using a liquid metal working fluid, a cavity at the top, a jet gradient array arrangement, and cylindrical needle fins and rectangular ribs at the bottom. This design aims to enhance the heat transfer performance of the jet impingement, while improving the poor fluidity of liquid metal, effectively reducing the flow pressure drop, and improving the temperature uniformity of the heat dissipation surface. Summary of the Invention

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] Technical solution: A jet microchannel radiator based on liquid metal, comprising a coolant inlet (1-1) and a coolant outlet (1-2, 1-3); the jet generating layer is a hollow cavity structure (2-1); the jet hole layer (2-2) is distributed with multiple jet holes to form a jet hole gradient array, where fluid is distributed and impacts the bottom of the microchannel; the bottom layer is located at the bottom of the radiator, and its fins (2-4) are not directly connected to the upper jet hole layer, forming a top groove area (2-5); at the same time, a large number of gradient array cylindrical needle fins (2-3) are provided at the bottom of the radiator.

[0007] Furthermore, the bottom rectangular gradient array ribs are not connected to the upper jet hole layer, forming a top groove area, and the height of the top groove area is one-fifth of the height of the microchannel ribs.

[0008] Furthermore, the bottom of the microchannel is provided with multiple cylindrical needle fins, which are located directly below the jet air, and the cross-sectional area of ​​each outer ring of the cylindrical needle fin is one-quarter larger than that of the inner ring.

[0009] Furthermore, the cross-sectional area of ​​each outer ring of the rectangular rib in the structure is one-third larger than that of the inner ring.

[0010] Furthermore, the material of the liquid metal-based jet heat sink is a corrosion-resistant ceramic substrate.

[0011] When working, the cooling liquid flows into the jet flow generating layer through the cooling liquid inlet, is distributed through the jet flow generating layer, enters the jet flow hole gradient array, forms a jet fluid impact on the cylindrical needle fin directly below, and is fully mixed at the bottom after impacting the needle fin to enhance heat transfer; the cooling liquid forms a local vortex after impacting the rectangular fin beside, and the top has a groove area so that the fluid can flow and mix, and the pressure drop is reduced, and the outlets at both ends of the radiator flow out respectively.

[0012] Beneficial effects: 1. Multiple cylindrical needle fins are placed at the bottom of the microchannel and directly below the jet flow hole. When the jet flow impacts, a local vortex can be formed by impacting the fin beside, which helps to enhance the impact effect of the jet flow.

[0013] 2. The fins and needle fins are arranged in an array gradient, which increases from inside to outside. This design can significantly improve the heat exchange capacity of the boundary area and effectively improve the temperature uniformity of the heat dissipation area.

[0014] 3. In the upper chamber, the jet flow holes are arranged in a gradient array, and the hole diameter of the jet flow holes becomes smaller and smaller from inside to outside. The jet flow hole layer is a sunken design, and the area of the edge of the radiator is the lowest. This design can effectively make the flow of the jet flow holes at the edge of the radiator more concentrated and faster. It can effectively improve the situation that the temperature at the edge of the bottom of the radiator is higher than that inside, and can effectively improve the temperature uniformity at the bottom of the radiator. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the overall schematic diagram of the jet flow microchannel radiator of the present application;

[0016] Figure 2 is the cross-sectional view of the jet flow microchannel radiator of the present application;

[0017] Figure 3 is the jet flow hole gradient array distribution diagram

[0018] Figure 4 is the needle fin and fin gradient array distribution diagram

[0019] Figure 5 is the jet flow hole layer sunken design cross-sectional view; DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. The description here refers to specific examples only to explain the present application and does not limit the present application.

[0021] Reference Figure 1 and Figure 2A liquid metal based jet micro-channel radiator, comprising a cooling liquid inlet (1-1) and a cooling liquid outlet (1-2) (1-3); the jet generating layer (2-1) is a hollow cavity structure; the jet hole layer (2-2) is provided with a plurality of jet holes, and details are shown in Figure 3 , a jet hole array is formed, fluid distribution is performed, and impact is made to the bottom of the micro-channel; the bottom layer (2-5) is located at the bottom of the radiator, the fins (2-4) are not directly connected to the jet hole layer above, a top groove area (2-5) is formed, and a plurality of cylindrical fins (2-3) are arranged at the bottom of the micro-channel. The micro-channel fins are not connected to the jet hole layer above, a top groove area is formed, and the height of the top groove area is one fifth of the height of the micro-channel fins. A plurality of cylindrical fins are arranged at the bottom of the micro-channel, and the cylindrical fins are arranged in an array gradient, and details are shown in Figure 4 , the cylindrical fins are located directly below the jet holes above.

[0022] The gradient array jet hole distribution is shown in Figure 3 , the jet holes have the same spacing in the same horizontal plane and the same vertical plane. The diameter of the jet holes decreases from the middle to the edge zone to ensure temperature uniformity, and the jet holes (3-8) are arranged in a gradient array, and the area of each circle of jet holes is one fourth smaller than that of the previous circle.

[0023] The needle fin gradient array and the fin gradient array are arranged as shown in Figure 4 , the needle fins are located directly below the jet holes above. The cross-sectional area of the cylindrical needle fins is one fourth larger than that of the inner circle for each outer circle. Similarly, the needle fins have the same spacing in the horizontal and vertical directions. The cross-sectional area of the rectangular fins is one third larger than that of the inner circle for each outer circle. The rectangular fins also have the same spacing in the horizontal and vertical directions.

[0024] Figure 5 The sinking design distribution of the jet layer is shown in

[0025] The liquid metal based jet micro-channel radiator is made of an aluminum nitride ceramic substrate.

[0026] The heat source chip is placed at the bottom of the radiator, so that the temperature above the heat source chip can be conducted to the radiator.

[0027] In operation, the cooling medium, liquid metal, enters the jet flow generation layer (2-1) inside the heat sink through the cooling liquid inlet (1-1). The jet flow generation layer is a precisely designed flow distribution cavity, and its core function is to integrate and equalize the incoming flow to ensure the stability of the subsequent jet flow. Then, the distributed cooling liquid enters the jet flow hole array with gradient characteristics, and the hole diameter of the array changes regularly along the flow direction, aiming to optimize the flow distribution and impact coverage.

[0028] The cooling liquid is ejected from the jet flow hole at a high speed, forming a concentrated jet flow that vertically impacts the cylindrical pin fin array at the bottom of the microchannel. This direct impact can effectively destroy the thermal boundary layer on the pin fin surface, resulting in a strong local convective heat transfer effect, which is a key link to improve heat transfer efficiency.

[0029] After the impact occurs, the fluid spreads around the pin fin surface and meets and mixes with the fluid spread by the adjacent jet flow in the bottom chamber. This sufficient forced mixing can effectively homogenize the fluid temperature, improve the overall heat transfer capacity, and weaken the temperature unevenness caused by jet flow separation.

[0030] Part of the fluid will further impact the rectangular upright ribs arranged beside the pin fin array after impacting the pin fin. This lateral impact will induce local vortices in the rib corner and gap area. These vortices enhance fluid disturbance, further strengthen the heat transfer near the wall, and can carry away the heat that may accumulate in the corner.

[0031] Finally, the cooling liquid that has completed heat exchange has a significantly higher temperature, and they are collected and flow out from the cooling liquid outlets at both ends (1-2) and (1-3) of the heat sink, entering the external circulation system for cooling, thus forming a complete and efficient active heat dissipation cycle.

[0032] The present application uses room temperature liquid metal as the cooling medium of the jet microchannel heat sink, combines the advantages of high thermal conductivity of liquid metal, and strengthens the cooling effect of high heat flux chips. The gradient array of jet flow holes and the gradient array structure with circular pin fins and rectangular ribs at the bottom can effectively improve the temperature distribution unevenness of the jet heat sink and improve the temperature uniformity of the heat sink.

[0033] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-layer gradient array jet structure based on liquid metal, comprising a coolant inlet (1-1) and coolant outlets (1-2)(1-3); the jet hole layer (2-2) is a sunken gradient structure with multiple jet holes of varying sizes distributed to form a jet hole gradient array, through which fluid impacts the bottom layer; the bottom layer (2-5) is located at the bottom of the radiator, and this layer is provided with an array of fins (2-4) and an array of cylindrical needle fins (2-3). During operation, liquid metal is introduced through the coolant inlet (1-1), integrated and diverted through the chamber layer (2-1), and enters the jet hole gradient array layer (2-1) to form a jet-like fluid that enters the bottom flow layer (2-5), collides with the needle fins and fins, and then flows out from the outlets (1-2)(1-3) at both ends of the radiator.

2. The multilayer gradient array jet structure based on liquid metal according to claim 1, characterized in that: The jet hole layer is an array-sunken design, with each layer being one-third higher than the bottom layer.

3. The multilayer gradient array jet structure based on liquid metal according to claim 2, characterized in that: The jet orifices are arranged in a gradient array, with the area of ​​each ring of jet orifices being one-quarter smaller than that of the previous ring.

4. The multilayer gradient array jet structure based on liquid metal according to claim 3, characterized in that: The bottom layer of needle fins and ribs is arranged in a gradient array, with the needle fins located directly below the upper jet holes. The cross-sectional area of ​​each outer ring of the cylindrical needle fin is one-quarter larger than that of the inner ring. The cross-sectional area of ​​each outer ring of the rectangular rib is one-third larger than that of the inner ring.

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