Composite micro-channel radiator for large-scale terahertz phased array

Abstract

The invention relates to a phased array antenna, in particular to a composite micro-channel radiator for a large-scale terahertz phased array, which comprises a plurality of radiating units, and a plurality of micro-channels with consistent flow directions are arranged in each radiating unit; the radiator further comprises a first-stage flow channel communicated with the multiple heat dissipation units, and the first-stage flow channel and the multiple heat dissipation units are located on the same plane. Inlets of the micro-channels in the heat dissipation units are all communicated with the first-stage channel, and outlets of the micro-channels in the heat dissipation units are all converged in the first-stage channel. After a cooling medium enters the radiator, the cooling medium firstly passes through the first-stage main flow channel and then is uniformly distributed into the four radiating units, so that redistribution of part of the cooling medium is realized, the problem of non-uniform flow in the micro-flow channel is effectively improved, and the temperature uniformity of a system is improved. Meanwhile, the first-stage flow channel comprises an inlet and an outlet, and the heat dissipation unit comprises a micro-flow channel, a flow distribution pipe and a collecting pipe which are integrally arranged on the same plane, so that the occupied longitudinal space is greatly reduced, and the packaging requirements of miniaturization and light weight of the terahertz phased array are perfectly met.

Description

Technical Field

[0001] This invention belongs to the field of terahertz phased array antenna technology, and particularly relates to a composite microchannel heat sink for large-scale terahertz phased arrays. Background Technology

[0002] Terahertz phased arrays combine the frequency advantage of terahertz waves with the flexible control capabilities of phased arrays, offering significant advantages in communication, radar, and imaging. However, due to the high frequency of terahertz waves, current components capable of generating and processing them are limited in number and have low energy conversion efficiency, making breakthroughs unlikely in the short term. To accelerate the engineering applications of terahertz, a feasible approach is to use phased arrays to address the insufficient transmission power of individual terahertz antennas. As the number of antennas increases, the large amount of heat released by the antenna system causes high and uneven temperatures in the phased array system, severely impacting the performance of large-scale phased array systems. Therefore, achieving effective thermal management of large-scale terahertz phased array systems is of great significance, and the miniaturization and integration of terahertz phased arrays present significant challenges.

[0003] Furthermore, terahertz array chips are typically manufactured using silicon-based or gallium arsenide and other semiconductor materials. Within the size-constrained chip package structure, heat is difficult to dissipate and conduct rapidly, further leading to localized overheating (hot spots). Since the performance of terahertz phased array systems is highly dependent on the device operating temperature, an uneven temperature field can significantly affect beam scanning accuracy and system reliability.

[0004] With the development of liquid cooling technology, it has evolved from air cooling technology and liquid-cooled microchannel cooling technology to the latest embedded microchannel cooling technology. This technology improves heat dissipation efficiency by directly integrating cooling channels into the material of heating elements (such as chips), reducing the resistance encountered by heat during the transfer process.

[0005] However, traditional microchannel heat sink structures (such as...) Figure 1 The DC microchannel shown Figure 2 The wave microchannel shown Figure 3 The honeycomb-shaped microchannels shown mainly include: microchannel inlet 1, microchannel outlet 2, radiator cold plate 3, flow channel 4, and ribs 5. Microchannel inlet 1 and microchannel outlet 2 are located at opposite ends of the radiator cold plate 3, with through holes measuring 1×1mm. The radiator cold plate 3 has dimensions of 40mm×40mm×0.5mm. The width of flow channel 4 and ribs 5 is 0.2mm, and the height of the ribs is 0.3mm. During operation, coolant enters the radiator cold plate 3 through microchannel inlet 1, then carries away heat through flow channel 4, and is discharged from microchannel outlet 2.

[0006] For example, the invention patent application with publication number CN109037882A discloses an airborne phased array antenna phase change heat storage liquid cooling heat dissipation box, which uses a combination of liquid cooling heat dissipation and phase change heat storage to achieve heat dissipation. Specifically: the bottom of the box body (1) is a heat dissipation base (3), the upper layer of the heat dissipation base (3) is a liquid cooling layer (4), and the lower layer is a phase change material layer (5); the liquid cooling layer is provided with an S-shaped liquid cooling channel (6), a liquid cooling inlet and a liquid cooling outlet; the phase change material layer is provided with multiple honeycomb-shaped partition cavities enclosed between the liquid cooling layer partition and the bottom plate of the box body; the liquid cooling channel uses the flow of liquid cooling liquid to transfer heat out; the phase change material layer uses the metal partitions that are interconnected between each partition cavity to quickly conduct the heat generated by the phased array antenna to the phase change material stored in the phase change material layer.

[0007] The aforementioned traditional microchannel heat sinks are primarily designed for systems with simple heat source distributions. When dealing with the complex heat source distributions of phased array chips, they struggle to simultaneously achieve rapid heat removal from localized high-heat-fluidity areas and balanced temperature control across the entire chip surface. This can easily lead to localized overheating, affecting system stability and electro-thermal coupling performance. Furthermore, existing microchannel structures often involve significant flow pressure drops, increasing pumping power and hindering long-term system operation.

[0008] For example, patent application CN118317553A discloses a liquid cooling circulation system for heat dissipation of phased array radar. The system includes: a liquid cooling structure located inside the radar, an inlet pipe, an outlet pipe, a heat exchanger, and a liquid cooling source. The outlet of the liquid cooling source is connected to the inlet pipe, and the inlet is connected to the heat exchanger. The outlet of the heat exchanger is connected to the liquid cooling source, and the inlet is connected to the outlet pipe. The inlet pipe and the outlet pipe extend into the phased array radar. This invention achieves rapid circulating heat dissipation for phased array radar.

[0009] This design employs separate liquid cooling systems for the intermediate and peripheral transceiver components, one with a rapid cooling capacity and the other with a lengthy flow path. This not only complicates the structure but also makes it unsuitable for terahertz phased arrays. This is because the design is only suitable for addressing heat dissipation issues in low-band phased array antennas, not for solving the heat dissipation and thermal equalization problems of high-frequency terahertz phased array antennas. Large-scale terahertz phased array antennas are not only small in overall size, but also in the size of their heat sources (e.g., terahertz wavelengths are extremely short, and antenna element spacing is only on the micrometer scale; therefore, even minute thermal deformation or temperature inhomogeneity can lead to phase errors between elements, causing beam pointing deviations, gain reductions, and increased sidelobe levels, severely degrading system performance), and these heat sources are widely distributed. Therefore, this design has limited effectiveness in solving the thermal equalization problem of large-scale terahertz phased array antennas.

[0010] For example, patent application CN116544204A discloses a liquid cooling structure, including: a liquid distribution structure, a first microchannel structure, a contact cold plate, and a second microchannel structure; the contact cold plate covers the second microchannel structure, and the first microchannel structure covers the contact cold plate; the liquid distribution structure is disposed above the first microchannel structure; the liquid distribution structure is propeller-shaped; the first microchannel structure is a structure designed for optical chips; and the second microchannel structure is a structure designed for switching chips.

[0011] However, terahertz phased arrays consist of a large number of densely arranged T / R (transmit / receive) units (i.e., heat sources), with uniform heat source distribution and full coverage. The above-mentioned solution is designed for a limited number of different optical chips, i.e., heterogeneous heat sources. Furthermore, its "regional differentiated heat dissipation design" (the first microchannel is for optical chips, and the second microchannel is for switching chips) cannot be directly adapted to the uniform heat source layout of the phased array. This may lead to local overheating or heat dissipation redundancy. For example, it is difficult to support the flow requirements of large-scale arrays, and the coolant flow of the end unit may be severely reduced, resulting in local overheating. In addition, the extension of the flow channel leads to an increase in pressure drop, a decrease in the heat dissipation efficiency of the far-end unit, and damage to temperature uniformity.

[0012] In addition, Chinese patent application CN202410868472.2 discloses a microchannel liquid-cooled radiator, including a fluid inlet, a fluid outlet, and a cold plate body. The fluid inlet and fluid outlet are disposed on a first surface of the cold plate body, and a second surface of the cold plate body opposite to the first surface is used to contact a heat source. A cavity is formed inside the cold plate body for fluid to flow from the fluid inlet to the fluid outlet. The cavity includes a throttling structure, a microchannel region, and an outlet buffer cavity. The throttling structure is connected to the center of the microchannel region. The outlet buffer cavity is disposed around the microchannel region and connected to the fluid outlet.

[0013] The above-mentioned scheme uses a central jet cooling method, which is only suitable for scenarios with concentrated heat sources (e.g., CPUs). Terahertz phased arrays are composed of a large number of densely arranged T / R (transmit / receive) units (i.e. heat sources), with uniform heat source distribution and full coverage. For example, there may be a situation where the core area is too cold while the edge heat dissipation is insufficient, resulting in an excessive temperature difference across the entire phased array and failing to match the uniform thermal load of the phased array.

[0014] Furthermore, in order to achieve uniform heat dissipation, the existing technology described above divides the entire heat sink microchannel into several heat dissipation zones, and these zones are arranged in a centrally symmetrical manner. Then, through a layered stacking structure design, the heat dissipation medium enters each zone from the center of symmetry, thereby achieving uniform flow of the heat dissipation medium to achieve uniform heat dissipation.

[0015] However, for chip-level heat sources such as terahertz phased arrays, the phased arrays need to be ultra-thin and lightweight to maintain beam scanning performance. Therefore, the space and weight budget left for the heat dissipation system is very limited. As a result, the layered stacked structure design will occupy more space in terms of height, especially for the largest array, where the thickness increases significantly, which will affect subsequent packaging (which is not conducive to thinning and lightweight design) and use, such as affecting the beam pointing accuracy and packaging density of the phased array. Summary of the Invention

[0016] The purpose of this invention is to provide a composite microchannel heat sink for large-scale terahertz phased arrays, which partially solves or alleviates the above-mentioned shortcomings in the prior art, and can achieve a thin and lightweight structural design while ensuring uniform heat dissipation.

[0017] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: A first aspect of the present invention is to provide a composite microchannel heat sink for a large-scale terahertz phased array, comprising a plurality of heat dissipation units, each heat dissipation unit having a plurality of microchannels with consistent flow direction; further comprising a primary channel communicating with the plurality of heat dissipation units, the primary channel and the plurality of heat dissipation units being located on the same plane; the inlets of the microchannels in the heat dissipation units are all communicating with the primary channel, and the outlets are all converging into the primary channel; the primary channel has a primary channel inlet and a primary channel outlet respectively provided on the two sides of the heat source matrix opposite to each other in the large-scale terahertz phased array; The plurality of heat dissipation units include a proximal heat dissipation unit adjacent to the inlet of the primary flow channel and a distal heat dissipation unit adjacent to the outlet of the primary flow channel; the number of proximal heat dissipation units and distal heat dissipation units are equal; the microchannel flow direction of all proximal heat dissipation units is consistent, the microchannel flow direction of all distal heat dissipation units is consistent, and the angle between the microchannel flow directions of the proximal heat dissipation units and the distal heat dissipation units is n°; The primary flow channel is divided into several branches at its inlet: a near-end branch leading to the inlet of the near-end heat dissipation unit and a far-end branch leading to the far-end heat dissipation unit. The far-end branch is further divided into far-end secondary branches leading to the far-end heat dissipation units on both sides. The outlet of each near-end heat dissipation unit is connected to the near-end return branch of the primary flow channel, and the outlet of each far-end heat dissipation unit is connected to the far-end return branch of the primary flow channel. All near-end return branches and all far-end return branches converge to reach the outlet of the primary flow channel.

[0018] Furthermore, the included angle of the flow direction of the microchannel is 90°.

[0019] Furthermore, there are four heat dissipation units, arranged in pairs, with two being near-end heat dissipation units and two being far-end heat dissipation units.

[0020] Furthermore, the primary flow channel is divided into three paths at its inlet: a near-end branch leading to the inlets of the two near-end heat dissipation units, and a far-end branch leading to the far-end heat dissipation unit. The far-end branch is further divided into two far-end secondary branches leading to the two far-end heat dissipation units. The outlets of the two near-end heat dissipation units are respectively connected to the two near-end return branches of the primary flow channel, and the outlets of the two far-end heat dissipation units are respectively connected to the two far-end return branches of the primary flow channel. The two near-end return branches and the two far-end return branches converge and lead to the outlet of the primary flow channel.

[0021] Furthermore, the inlets of the near-end heat dissipation unit and the far-end heat dissipation unit are respectively provided with distribution pipes connected to the inlet of the microchannel; the outlets of the near-end heat dissipation unit and the far-end heat dissipation unit are respectively provided with manifolds connected to the outlet of the microchannel.

[0022] Furthermore, the microchannel is one of a direct-flow microchannel, a wave-shaped microchannel, or a honeycomb microchannel.

[0023] Furthermore, the width of the primary flow channel is 0.9 mm - 1.1 mm, and the width of the microflow channel is 0.18 mm - 0.22 mm.

[0024] Furthermore, the composite microchannel radiator includes a cold plate and a cover plate that snaps onto the cold plate; the primary flow channel and the microchannel are disposed on the cold plate.

[0025] Furthermore, the primary flow channel inlet and primary flow channel outlet are respectively located at both ends of the composite microchannel radiator.

[0026] Beneficial effects: The primary flow channel of this invention, including the inlet and outlet, and the heat dissipation unit, including the microchannels, distribution pipes, and manifolds, are integrated into a single plane (i.e., a single-layer topology design, with both microchannels and primary flow channels being embedded). All flow channel structures are formed within the same substrate through a single or continuous etching process, eliminating the need for the vertical stacking of the primary flow channel layer and microchannel layer in traditional layered designs, thus improving the matching degree between the heat dissipation unit and the array heat source. Compared to layered designs that require at least two substrate thicknesses and the vertical length of interlayer connection structures such as vertical vias, the vertical height of this invention is determined only by the thickness of a single substrate, greatly reducing the vertical space occupied and perfectly meeting the thin packaging requirements of terahertz phased arrays.

[0027] The flow channel turning and branching are all completed in a plane, eliminating the need for complex three-dimensional turning structures such as layered turning pipes or three-dimensional manifolds, thus avoiding the increase in vertical height caused by such structures. The reduced vertical height allows the heat sink to be directly embedded and integrated into the bottom of the chip or in the phased array structure, matching the package thickness of silicon-based / gallium arsenide chips. This provides ample vertical space for the dense arrangement of large-scale array units such as 10×10 heat source arrays, improving system integration density.

[0028] In this invention, the heat dissipation unit is divided into two near-end and two far-end units. The primary flow channel inlet is symmetrically supplied in three directions. The cooling medium in both the near-end and far-end units undergoes the same number of 90° turns before entering the microchannel, resulting in consistent local resistance and eliminating flow deviations caused by differences in turning direction. Furthermore, after the fluid outflow from the far-end unit merges with the liquid outflow from the near-end unit in the primary channel, the liquid velocity is not only buffered initially, but the liquid after merging also needs to undergo another 90° turn before entering the outlet, thus achieving secondary buffering. This allows the flow velocity to gradually stabilize and avoids the problem of local low pressure. As a result, even with only one outlet, the flow rate and temperature can meet the requirements, eliminating the need for multiple outlets or more complex structural designs. This provides more encapsulation points and is more conducive to miniaturization and lightweight design.

[0029] Traditional single-path serpentine or parallel flow channels have an inherent drawback: the coolant continuously absorbs heat during flow, causing its temperature to gradually increase from the inlet to the outlet (i.e., a "temperature rise"). This results in the cooling capacity of the outlet region being much lower than that of the inlet region, creating a large temperature gradient on the chip surface. In this invention, the near-end return flow velocity is high, and at the confluence, it is cut off by the back pressure of the low-velocity fluid at the far end, reducing the velocity. The far-end flow velocity is low, and the cutoff effect is weak, ultimately achieving a convergence of flow velocities between the near and far units. This reduces the possibility of excessively high local fluid temperatures, significantly reducing or even eliminating the near-cold-far-hot temperature gradient between units. Furthermore, since the primary flow channel surrounds the two far-end heat dissipation units, it achieves confluence between the near and far units and reduces the flow resistance at the confluence point, weakening the negative impact of differences in flow resistance between branches on the overall flow distribution. This reduces the number of cooling dead zones caused by uneven flow resistance, further improving cooling uniformity.

[0030] The arrangement of the primary flow channel and the orientation of the heat dissipation units in this invention can reduce the flow path of the coolant from the inlet to the outlet to a certain extent, thereby reducing the temperature difference between the coolant flowing through the near end and the far end, and further reducing the temperature difference between the near end and the far end heat source array. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0032] Figure 1 This is a schematic diagram of the flow channel structure of a traditional DC microchannel (RM) heat sink; Figure 2 A schematic diagram of the flow channel structure of a traditional wave-type microchannel (WM) radiator; Figure 3 This is a schematic diagram of the flow channel structure of a traditional honeycomb microchannel (SM) heat sink; Figure 4 This is a schematic diagram of the flow channel structure of a composite microchannel heat sink in one embodiment of the present invention; Figure 5 This is a schematic diagram of the flow channel structure of the composite microchannel heat sink in another embodiment of the present invention; Figure 6 This is a schematic diagram of the flow channel structure of the composite microchannel heat sink in another embodiment of the present invention; Figure 7 This is an exploded view of the present invention; Figure 8 A temperature difference comparison diagram between the composite microchannel radiator provided by the present invention and a traditional microchannel radiator; Figure 9 A comparison chart of pumping power between the composite microchannel radiator provided by this invention and a traditional microchannel radiator.

[0033] Summary of reference numerals in the attached diagram: 1-Primary flow channel inlet, 2-Primary flow channel outlet, 3-Cold plate, 4-Micro channel, 5-Rib, 6-Primary flow channel, 7-Cover plate, 8-Heat source, 101-Proximal branch, 102-Distal branch, 103-Distal secondary branch, 104-Proximal return branch, 105-Distal return branch, 106-Distribution pipe, 107-Manifold. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0036] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0039] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0040] like Figure 7 As shown, this embodiment provides a composite microchannel heat sink for large-scale terahertz phased arrays, including several heat dissipation units, each heat dissipation unit having multiple microchannels 4 with consistent flow direction; it also includes a primary channel 6 surrounding and communicating with several heat dissipation units, the primary channel 6 and several heat dissipation units being located on the same plane; the inlets of the microchannels 4 in the heat dissipation units are all connected to the primary channel 6, and the outlets are all converged in the primary channel 6.

[0041] In this embodiment, the primary flow channel 6 includes a primary flow channel inlet 1, a primary flow channel outlet 2, and the microflow channels 4 of the main distribution section and the heat dissipation unit, all machined on the same substrate plane. The two are directly connected through in-plane flow channel branches, eliminating the need for cross-layer connections. The primary flow channel inlet 1 and the primary flow channel outlet 2 correspond to opposite sides of the matrix array formed by the large-scale heat sources 8 in the large-scale terahertz phased array. Preferably, the primary flow channel inlet 1 and the primary flow channel outlet 2 are symmetrically arranged or located on the central axis of the cold plate.

[0042] Compared to the layered design in the prior art, the present invention does not require separate primary flow channel layers of 6 layers and secondary microflow channel layers of 4 layers. The entire flow path can be achieved through a single plane etching process, eliminating the need for interlayer material thickness such as additional substrate, cover plate layers of 7 layers, and vertical connection structures such as through holes and transition pipes.

[0043] Both the primary flow channel 6 and the microflow channel 4 are processed by etching. The same planar design can form the three-dimensional morphology of the primary flow channel 6 and the microflow channel 4 on the same substrate by single or continuous etching, avoiding the thickness accumulation caused by layer bonding. The vertical height can be precisely controlled within the thickness of a single substrate, such as 0.5 mm.

[0044] The reduction in vertical height directly reduces the space occupied by the heat sink in the chip packaging structure, reserving more vertical space for the high-density array arrangement of large-scale terahertz phased arrays, which can support the integration of more array units or reduce the overall package volume.

[0045] Since the primary flow channel inlet 1 of the primary flow channel 6 is not at the center point of multiple heat dissipation units, the distance from the heat dissipation medium to each heat dissipation unit is not equal.

[0046] The short distance between the near-end heat dissipation unit (close to the primary flow channel inlet 1) and the primary flow channel inlet 1 results in low flow path resistance and faster inflow of cooling medium, which may lead to excessive flow rate of medium per unit time. The long distance between the far-end heat dissipation unit (close to the primary flow channel outlet 2) and the inlet results in high flow path resistance, slow inflow of medium, and relatively insufficient flow rate.

[0047] The heat dissipation efficiency of terahertz phased array chips is directly related to the flow rate of the cooling medium; that is, the greater the flow rate, the more heat is transferred per unit time. Near-end cells may experience "overcooling" due to excessive flow, while far-end cells may experience "undercooling" due to insufficient flow, resulting in a significant temperature gradient on the chip surface—lower near-end temperature and higher far-end temperature—leading to localized overheating and affecting beam scanning accuracy and system reliability.

[0048] If all heat dissipation units adopt the same flow direction, such as the flow direction being consistent and parallel to the primary flow channel 6, the flow resistance is determined only by the distance, which cannot offset the flow deviation caused by the non-center of the inlet, further amplifying the problem of uneven heat dissipation.

[0049] To solve the problem of uneven heat dissipation, such as Figure 4-Figure 6 As shown, in this embodiment, the plurality of heat dissipation units include a proximal heat dissipation unit adjacent to the primary flow channel inlet 1 and a distal heat dissipation unit adjacent to the primary flow channel outlet 2; the number of proximal heat dissipation units and distal heat dissipation units is equal; the microchannels 4 of all proximal heat dissipation units have the same flow direction (e.g., Figure 5 As shown, all are parallel to the distal branch 102 extending from the primary flow channel inlet 1 to the primary flow channel outlet 2; or, as Figure 6 As shown, the microchannels 4 of all remote heat dissipation units have the same flow direction (e.g., Figure 5 As shown, the flow diffuses outward from the distal branch 102 to the distal heat dissipation units on both sides, and the flow direction angle between the microchannel 4 of the proximal heat dissipation unit and the microchannel 4 of the distal heat dissipation unit is n°. By adjusting the direction of the microchannel 4 of the proximal and distal heat dissipation units, the heat dissipation effect of the distal and proximal heat dissipation units is made to be nearly identical.

[0050] More specifically, in this embodiment, the included angle of the flow direction of the microchannel 4 is 90°; wherein the inlet direction of the microchannel 4 of the near-end heat dissipation unit is an acute angle with the flow direction of the composite microchannel 4 heat sink, and the inlet direction of the microchannel 4 of the far-end heat dissipation unit is an obtuse angle with the flow direction of the composite microchannel 4 heat sink; the flow direction of the composite microchannel 4 heat sink is the direction of the line connecting the inlet 1 and the outlet of the primary flow channel.

[0051] According to traditional logic, near-end heat dissipation units, being close to the inlet, naturally have low frictional resistance and short flow paths, making them prone to excess flow; while far-end units, being far from the inlet, have high frictional resistance and long flow paths, making them prone to insufficient flow. Theoretically, to balance flow, near-end resistance should be increased and far-end resistance decreased, such as by turning the near-end flow channel to increase local resistance and making the far-end flow channel parallel to reduce local resistance. However, this implementation uses a counterintuitive approach, employing an acute angle (including 0°, i.e., parallel) for the near-end inlet and an obtuse angle (including 90°, i.e., perpendicular) for the far-end inlet. This is because this embodiment has four heat dissipation units, arranged in pairs, with two near-end units and two far-end units. To facilitate the supply of cooling medium, the primary flow channel 6 is divided into three paths at the inlet: a near-end branch 101 leading to the inlets of the two near-end heat dissipation units and a far-end branch 102 leading to the far-end heat dissipation units; the far-end branch 102 is further divided into two far-end secondary branches 103, each leading to one of the two far-end heat dissipation units. Furthermore, the proximal branch 101 is perpendicularly connected to the distal branch 102; the proximal branch 101 is connected to the proximal heat dissipation unit after a vertical turn at point A; the distal branch 102 and the distal secondary branch 103 are connected by a vertical turn at point B.

[0052] The two proximal branches 101 and distal branches 102 are perpendicularly connected, and then connect to the proximal and distal heat dissipation units respectively after vertical turns. After this setup, the heat dissipation medium in both the proximal and distal heat dissipation units enters the microchannel 4 inlet directly after a 90° turn. The problem of low proximal resistance and high distal resistance in traditional logic is eliminated in this embodiment by forcibly equalizing the number of channel turns. Before entering the microchannel 4, the cooling medium in both the proximal and distal units must undergo a 90° turn, ensuring that the number of turns and angles of the core components of local resistance are completely consistent, differing only in the path length before entering the heat dissipation unit.

[0053] The reason for making the flow velocity of the heat dissipation medium in the near-end heat dissipation unit and the far-end heat dissipation unit more consistent lies in the recirculation design. In this embodiment, the outlets of the two near-end heat dissipation units are respectively connected to the two near-end recirculation branches 104 of the primary flow channel 6, and the outlets of the two far-end heat dissipation units are respectively connected to the two far-end recirculation branches 105 of the primary flow channel 6; the two near-end recirculation branches 104 and the two far-end recirculation branches 105 converge and reach the outlet of the primary flow channel 6. The fluid in the near-end recirculation branch 104 needs to converge with the heat dissipation medium in the far-end recirculation branch 105. During the convergence process, the heat dissipation medium in the far-end recirculation branch 105 will have a certain interception effect on the heat dissipation medium in the near-end recirculation branch 104, thereby reducing the flow velocity of the heat dissipation medium in the near-end heat dissipation unit. The reduced flow velocity just makes up for the difference in path length before entering the heat dissipation unit, making the flow velocity of the heat dissipation medium in the near-end heat dissipation unit and the far-end heat dissipation unit more consistent, greatly improving the heat dissipation uniformity of the two.

[0054] In order to ensure that the flow conditions of each microchannel 4 in the heat dissipation unit are consistent, in this embodiment, the inlet of the near-end heat dissipation unit and the far-end heat dissipation unit are provided with a distribution pipe 106 that is connected to the inlet of the microchannel 4 respectively; the outlet of the near-end heat dissipation unit and the far-end heat dissipation unit are provided with a manifold 107 that is connected to the outlet of the microchannel 4 respectively.

[0055] Furthermore, this embodiment does not limit the specific form of the microchannel 4; it can be as follows: Figure 4 The DC type shown can be as follows: Figure 5 The wave pattern shown can also be as follows: Figure 6 The honeycomb pattern shown.

[0056] In this embodiment, the composite microchannel 4 heat sink includes a cold plate 3 and a cover plate 7 that is fastened to the cold plate 3, and the two are bonded together with thermally conductive adhesive; the primary flow channel 6 and the microchannel 4 are disposed on the cold plate 3. The dimensions of the cold plate 3 and the cover plate 7 are both 40mm × 40mm × 0.5mm, the width of the primary flow channel 6 is 0.9-1.1mm, and the width of the microchannel 4 is 0.18-0.22mm. The heat source 8, i.e., the terahertz phased array, has a size of 1mm × 1mm × 0.13mm and is centrally distributed on the cover plate 7 in a 10×10 array; the heat sink cover plate 7 and the microchannel 4 cold plate 3 are tightly connected by silicon-silicon bonding, and a cooling cavity for coolant flow is formed in the middle.

[0057] During operation, the heat source 8 is connected to the power supply for heating. Then, the coolant enters the primary main channel from the primary channel inlet 1, and then flows into the secondary micro channel 4 for heat dissipation. Finally, it is concentrated in the primary main channel and the heat is carried out through the micro channel 4 outlet, completing the entire heat dissipation process.

[0058] like Figures 8-9 The figures shown are a comparison of temperature difference and pumping power between the novel composite microchannel 4-radiator and the traditional microchannel 4-radiator, respectively. The temperature difference at the heat source surface (…) ) and pumping power ( ) is represented as: (1) (2) In the formula: This indicates the highest surface temperature of the heat source; Indicates the lowest surface temperature of the heat source; Indicates the fluid inlet velocity; This represents the cross-sectional area of ​​the fluid inlet (i.e., the cross-sectional area of ​​the inlet 1 of the primary flow channel). This indicates the fluid pressure drop.

[0059] Figure 8 The temperature difference of the heat source varies with the Reynolds number. Re The curve of change of ) Re It is an important dimensionless parameter characterizing the fluid flow state, and its mathematical expression is: (3) In the formula: Indicates the average fluid density; Hydraulic diameter representing the inlet cross-section (i.e., the cross-sectional area of ​​inlet 1 of the first-stage flow channel); This indicates the dynamic viscosity of the fluid.

[0060] The graph shows that the temperature difference of the heat source of all radiators varies with... Re The temperature decreases with increasing Reynolds number, and the trend is quite significant. Furthermore, the new composite microchannel 4-radiator exhibits better temperature uniformity than the traditional microchannel 4-radiator at the same Reynolds number. For example... Figure 8 As shown, in Re At a temperature of 1500°C, the surface temperature differences of the heat source in traditional microfluidic channel 4 (RM, WM, and SM) heat sinks were 7.03 K, 6.65 K, and 7.39 K, respectively, while those in novel composite microfluidic channel 4 (NC-RM, NC-WM, and NC-SM) heat sinks were 6.32 K, 6.09 K, and 6.83 K, respectively. The novel composite microfluidic channel 4 heat sinks showed improved temperature uniformity of 11.2%, 9.2%, and 8.2% compared to their corresponding traditional counterparts. These results not only contribute to improving the overall performance and reliability of terahertz phased array antennas but also reduce thermal stress in the antenna structure, thereby extending antenna lifespan. Furthermore, the novel composite microfluidic channel 4 heat sink is not only suitable for thermal management of terahertz phased array antennas but also has potential in a wider range of microfluidic applications. Its significantly reduced flow resistance makes it promising for applications in microfluidic chips, fuel cell cooling, and other fields. To extend these research results to other applications, the channel geometry can be parameterized to accommodate different fluid properties.

[0061] from Figure 9 It can be seen that there is a significant difference in pumping power between the traditional microchannel 4-radiator and the new composite microchannel 4-radiator. However, the difference is not very obvious at low Reynolds numbers, but as the Reynolds number increases, especially... Re After 500, the differences become increasingly apparent. Re At 1500, the pumping power of traditional microchannel 4 (RM, WM, and SM) radiators is 59.72mW, 61.16mW, and 55.7mW, respectively. The composite microchannel 4 ( ) provided by this invention Figure 4 NC-RM, Figure 5 NC-WM and Figure 6 The pumping power of the NC-SM radiator in this invention is 37.32mW, 37.32mW, and 35.84mW, respectively. The composite microchannel 4 radiator in this invention reduces the pumping power by 37.5%, 39%, and 35.7% compared to the corresponding conventional microchannel 4 radiators, respectively. This indicates that the composite microchannel 4 radiator of this invention has a lower pumping power at high Reynolds numbers than the conventional microchannel 4 radiator, which also means that they require less energy under the same flow conditions. Furthermore, it achieves the same maximum heat source temperature as the conventional microchannel 4 radiator at a lower pumping power, which is significant for reducing energy consumption costs.

[0062] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0063] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A composite microchannel heat sink for large-scale terahertz phased arrays, characterized in that... include: Several heat dissipation units, each heat dissipation unit is provided with multiple microchannels with the same flow direction (4). A primary flow channel (6) is connected to several heat dissipation units, and the primary flow channel (6) and several heat dissipation units are located on the same plane; the micro-channel inlets in the heat dissipation units are all connected to the primary flow channel (6), and the outlets are all converged in the primary flow channel (6); the primary flow channel (6) is provided with a primary flow channel inlet (1) and a primary flow channel outlet (2) on the two sides of the heat source matrix in the large-scale terahertz phased array respectively. The plurality of heat dissipation units include a proximal heat dissipation unit adjacent to the primary flow channel inlet (1) and a distal heat dissipation unit adjacent to the primary flow channel outlet (2); the number of proximal heat dissipation units and distal heat dissipation units are equal; the microchannels (4) of all proximal heat dissipation units have the same flow direction, the microchannels (4) of all distal heat dissipation units have the same flow direction, and the microchannel flow direction angle between the microchannels (4) of the proximal heat dissipation units and the microchannels (4) of the distal heat dissipation units is n°. The primary flow channel (6) is divided into several branches at the primary flow channel inlet (1), namely a near-end branch (101) leading to the inlet of the near-end heat dissipation unit and a far-end branch (102) leading to the far-end heat dissipation unit; the far-end branch (102) is further divided into far-end secondary branches (103) leading to the far-end heat dissipation units on both sides respectively; the outlet of each near-end heat dissipation unit is connected to the near-end return branch (104) of the primary flow channel (6), and the outlet of each far-end heat dissipation unit is connected to the far-end return branch (105) of the primary flow channel (6); all near-end return branches (104) and all far-end return branches (105) converge and lead to the primary flow channel outlet (2) of the primary flow channel (6).

2. The composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The proximal branch (101) is perpendicularly connected to the distal branch (102); the proximal branch (101) is connected to the proximal heat dissipation unit after a vertical turn; the distal branch (102) is perpendicularly connected to the distal secondary branch (103).

3. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The included angle of the microchannel flow direction is 90°; wherein the inlet direction of the microchannel of the near-end heat dissipation unit is an acute angle with the flow direction of the composite microchannel heat sink, and the inlet direction of the microchannel of the far-end heat dissipation unit is an obtuse angle with the flow direction of the composite microchannel heat sink; the flow direction of the composite microchannel heat sink is the line direction connecting the primary channel inlet (1) and the primary channel outlet (2).

4. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: There are four heat dissipation units, which are arranged in pairs, with two being near-end heat dissipation units and two being far-end heat dissipation units.

5. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 4, characterized in that: The primary flow channel (6) is divided into three paths at the primary flow channel inlet (1): two near-end branches (101) leading to the inlets of the two near-end heat dissipation units, and a far-end branch (102) leading to the far-end heat dissipation unit; the far-end branch (102) is further divided into two far-end secondary branches (103) leading to the two far-end heat dissipation units respectively; the outlets of the two near-end heat dissipation units are respectively connected to two near-end return branches (104) of the primary flow channel (6), and the outlets of the two far-end heat dissipation units are respectively connected to two far-end return branches (105) of the primary flow channel (6); the two near-end return branches (104) and the two far-end return branches (105) converge and lead to the primary flow channel outlet (2). The proximal branch (101) is perpendicularly connected to the distal branch (102); the proximal branch (101) is connected to the proximal heat dissipation unit after a vertical turn; the distal branch (102) is perpendicularly connected to the distal secondary branch (103).

6. A composite microchannel heat sink for large-scale terahertz phased arrays according to any one of claims 1 to 5, characterized in that: The inlet of the near-end heat dissipation unit and the far-end heat dissipation unit are provided with a distribution pipe (106) that is connected to the inlet of the microchannel respectively; the outlet of the near-end heat dissipation unit and the far-end heat dissipation unit are provided with a manifold (107) that is connected to the outlet of the microchannel respectively.

7. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The microchannel (4) is one of a direct-flow microchannel, a wave-shaped microchannel, or a honeycomb microchannel.

8. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The width of the primary flow channel (6) is 0.9 mm - 1.1 mm, and the width of the microflow channel (4) is 0.18 mm - 0.22 mm.

9. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The primary flow channel (6) has a primary flow channel inlet (1) and a primary flow channel outlet (2) located at both ends of the composite microchannel radiator.

10. A composite microchannel heat sink for large-scale terahertz phased arrays according to claim 1, characterized in that: The composite microchannel radiator includes a cold plate (3) and a cover plate (7) that snaps onto the cold plate (3); the primary channel (6) and the microchannel (4) are disposed on the cold plate (3).

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