A low-thermal-resistance low-pump-power microchannel heat sink with good stability

Abstract

A kind of low thermal resistance low pump power good stability manifold microchannel radiator, belong to the field of heat transfer enhancement.From top to bottom include cover plate (1), manifold splitter (2) and microchannel substrate (4);Cover plate (1) is machined with the through hole connected with external pipeline, fluid inlet (10) and fluid outlet (11) respectively;Manifold splitter (2) is machined with inlet reservoir (7), inlet manifold channel (8), outlet manifold channel (3) and outlet reservoir (9);Microchannel substrate includes a series of microchannel radiator units consisting of microchannel (5) and flow limiting channel (6).Flow limiting channel is arranged below manifold channel.Through arranging flow limiting channel below manifold channel, the wall temperature distribution perpendicular to microchannel direction is greatly improved;The manifold microchannel involved in the present application can effectively reduce the maximum wall temperature and improve the wall temperature distribution to meet the heat dissipation requirements of high-power devices.

Description

Technical Field

[0001] This invention belongs to the field of enhanced heat transfer and relates to a manifold microchannel heat sink for high-power devices. Background Technology

[0002] With the large-scale commercial application of wide-bandgap semiconductor materials (gallium nitride, silicon carbide), the size of electronic devices, represented by power converters (DC-DC), is constantly shrinking, and power density is skyrocketing. For example, gallium nitride high electron mobility transistors (HEMTs) can operate at higher frequencies, which is beneficial for reducing the size of power converters. However, the switching losses caused by high switching frequencies result in heat flux on the device surface exceeding 10 kilowatts. 2 W / cm 2 This temperature exceeds the limits of traditional cooling methods. If an appropriate cooling solution is not adopted, the temperature of electronic components will be too high, which will inevitably increase the failure rate of the components, resulting in reduced reliability and shortened service life.

[0003] In 1981, scholars first proposed the concept of "microchannel heat sinks." Compared with conventional channels, microchannels have advantages such as large specific surface area, light weight, and the ability to be integrated onto electronic device substrates. Therefore, microchannel heat sink liquid cooling is considered an effective method for solving heat dissipation in electronic devices. After nearly half a century of research, it has been found that microchannel liquid phase cooling technology still has some problems, such as uneven flow distribution in parallel channels and reduced heat transfer efficiency along the flow direction, leading to uneven temperature distribution on the device surface and causing it to be subjected to excessive thermal stress for a long time. Manifold microchannels can shorten the microchannel length by using manifolds, reducing pump power and improving convective heat transfer efficiency; on the other hand, they can improve the problem of temperature unevenness by utilizing the advantage of phase change energy to dissipate extremely high heat flux under extremely small temperature differences. However, manifold microchannels still have many problems. For example, although U-shaped manifolds can ensure uniform flow distribution, the manufacturing process is complex and the sealing performance is poor, while Z-shaped manifolds, although simple in structure, have uneven flow distribution. Studies have shown that uneven flow distribution seriously affects the wall surface temperature distribution characteristics. Moreover, this uneven flow distribution is even more pronounced in multi-heat source systems such as DC-DC power converters and pump sources, where uneven temperature distribution and "hot spot" phenomena are caused. In addition, when a phase change occurs within the microchannel, uneven flow distribution can exacerbate boiling instability, leading to increased pump power consumption and a lower heat dissipation limit.

[0004] Therefore, optimizing the structure based on the Z-type manifold is crucial for reducing pump power, improving heat dissipation capacity, and enhancing temperature distribution characteristics, paving the way for the next step of applying manifold microchannel radiators to multi-heat source systems. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a highly efficient manifold microchannel heat dissipation solution that can reduce pump power, enhance heat exchange, and improve temperature distribution characteristics, such as...Figures 1-3 As shown, the feature is that it includes a cover plate (1), a manifold distribution plate (2) and a microchannel substrate (4) in sequence. The cover plate (1) covers the manifold distribution plate (2), and the manifold distribution plate (2) covers the microchannel substrate (4) directly above it. The cover plate (1) is processed with a fluid inlet (10) and a fluid outlet (11) connected to an external pipe.

[0006] The manifold diverter plate (2) is machined with an inlet reservoir (7), an inlet manifold channel (8), an outlet manifold channel (3), and an outlet reservoir (9). The manifold diverter plate (2) is vertically connected at corresponding locations of the inlet reservoir (7), the inlet manifold channel (8), the outlet manifold channel (3), and the outlet reservoir (9). The inlet reservoir (7) and the outlet reservoir (9) are separated by a bent baffle wall (12). On the side corresponding to the inlet reservoir (7), the bent baffle wall (12) is... Four parallel channels, namely four inlet manifold channels (8), are formed between them, and the inlet manifold channels (8) are connected to the inlet storage tank (7); four parallel channels, namely outlet manifold channels (3), are formed between the ribs (12) that bend and deflect the flow on the side of the outlet storage tank (9), and the outlet manifold channels (3) are connected to the outlet storage tank (9); the outlet manifold channels (3) and the inlet manifold channels (8) are arranged in parallel and intersecting order, and the outlet manifold channels (3) and the inlet manifold channels (8) are separated by ribs (12);

[0007] The fluid inlet (10) and outlet (11) on the cover plate (1) correspond to the inlet liquid storage tank (7) and outlet liquid storage tank (9) on the manifold distribution plate (2) and are connected to each other;

[0008] The microchannel substrate (4) includes microchannel regions (5) and current-limiting channel regions (6) arranged in parallel and intersecting order. At both ends of the microchannel regions (5) and current-limiting channel regions (6), there are planar structures without microchannels. The microchannel regions (5) are composed of multiple parallel microchannels, and the current-limiting channel regions (6) are composed of multiple parallel current-limiting channels. The intersecting direction of the microchannel regions (5) and current-limiting channel regions (6) is consistent with the length direction of the microchannels and the length direction of the current-limiting channels. The current-limiting channel region (6) is located in the inlet manifold channel (8). The length of each flow-limiting channel in the flow-limiting channel area (6) is equal to the width of the inlet manifold channel (8), and the length direction of the flow-limiting channel is perpendicular to the width of the manifold channel (8). The ribs (12) of the outlet manifold channel (3) and the outlet manifold channel (8) and the area below the outlet manifold channel (3) correspond to the microchannel area (5). The areas below the inlet reservoir (7) and the outlet reservoir (9) correspond to the planar structures at both ends of the microchannel area (5) and the flow-limiting channel area (6) on the microchannel substrate (4).

[0009] The width of the microchannels in the microchannel region (5) is greater than the width of the flow-limiting channel in the flow-limiting channel region (6), and the spacing of the microchannels in the microchannel region (5) is less than the spacing of the flow-limiting channel in the flow-limiting channel region (6).

[0010] Four inlet manifold channels (8), three of which are of equal width, and the other one on the side is narrower, being half the width of the three above; four outlet manifold channels, three of which are of equal width, and the other one on the side is narrower, being half the width of the three above; the narrower inlet manifold channel (8) and the narrower outlet manifold channel are respectively located on both sides of the manifold splitter plate (2).

[0011] The microchannel region of the microchannel substrate (4) is the same size as the power device that needs to be cooled.

[0012] To clarify the assembly method of the cover plate (1), the manifold distribution plate (2), and the microchannel substrate (4) and the relative positions of each structure, Figure 4-7 The following are presented: a front view of the microchannel heat sink, a sectional view of the cover plate (AA sectional view), a sectional view of the manifold splitter plate (BB sectional view), and a sectional view of the microchannel substrate (CC sectional view).

[0013] Combination Figures 1-8 The technical solution of the present invention is further explained below:

[0014] After the cover plate (1), manifold distribution plate (2) and microchannel substrate (4) are bonded together, they are connected to the liquid supply system to form a sealed system. The flow path of the fluid in the microchannel radiator is as follows: fluid inlet (10), inlet reservoir (7), inlet manifold channel (8), flow restriction channel (6), microchannel (5), outlet manifold channel (3), outlet reservoir (9) and fluid outlet (11). The fluid enters the manifold distribution plate (2) through the fluid inlet (10) on the cover plate (1); the manifold distribution plate includes the inlet reservoir (7), inlet manifold channel (8), outlet manifold channel (3) and outlet reservoir (9), wherein the inlet manifold channel (8) and the outlet manifold channel (3) are separated by ribs. The fluid entering the radiator from the fluid inlet (10) enters the four inlet manifold channels (8) through the inlet reservoir (7). Due to obstruction by the manifold ribs, the fluid in the inlet manifold channel (8) flows downward into the flow-limiting channel (6) driven by the micropump outside the fluid inlet (10). Subsequently, the fluid is obstructed by the substrate of the microchannel substrate (4), and the fluid turns 90°, flowing in the microchannel (5) in a direction perpendicular to the inlet manifold channel (8). Next, in the microchannel directly below the outlet manifold channel (3), the fluid is obstructed by the wall (including the rib wall) or the fluid itself, and turns 90° again, flowing vertically upward out of the microchannel (5) and into the outlet manifold channel (3). Finally, because the four outlet manifold channels (3) are connected to the outlet reservoir (7), the fluid flowing into the outlet manifold channels (3) collects in the outlet reservoir (7) and flows out of the microchannel radiator from the fluid outlet (11). During the fluid flow process, heat is absorbed using sensible heat and latent heat to dissipate heat from the electronic device.

[0015] The present invention has the following advantages and effects:

[0016] 1. Vertical fluid inlet and outlet of the microchannel radiator. As a heat dissipation unit, the microchannel radiator can be integrated into the cold plate of a multi-heat source system such as a DC-DC converter module and a pump source.

[0017] 2. Based on the inlet and outlet liquid storage tanks, the fluid is evenly distributed into the microchannels using manifold channels and flow-limiting channels, thereby significantly improving the temperature distribution of the radiator's heated surface. This is of great significance for reducing thermal stress and minimizing thermal fatigue.

[0018] 3. Based on achieving uniform flow distribution, and leveraging the characteristic of phase change to dissipate extremely high heat flux under minimal temperature differences, organic working fluids are used as cooling media, such as HFE-7100, which can dissipate 300 W / cm³ at extremely low flow rates. 2 The heat flux density can be increased by more than double, which has significant application prospects in the field of thermal management of electronic devices.

[0019] 4. As mentioned above, under the same heat dissipation power, single-phase and two-phase heat exchange can be achieved by using different working fluids. And using... Figures 2-3 The flow pattern shown illustrates how a flow-limiting channel positioned below the inlet manifold can suppress boiling instability caused by excessive supercooling, thereby increasing the heat transfer coefficient and critical heat flux density, i.e., maximum heat dissipation power. When using deionized water as the working fluid in a single-phase cooling scheme, the fluid inlet and outlet are reversed, meaning the flow-limiting channel is positioned below the outlet manifold. Figure 8 As shown, under the condition of ensuring uniform flow distribution, the fluid exhibits a "jet" impact effect near the outlet, which increases the heat transfer coefficient, reduces the wall temperature near the outlet, and makes the temperature distribution of the heated surface more uniform.

[0020] 5. Studies have shown that the manifold distributor plate has a relatively small impact on heat transfer performance. Therefore, to reduce costs, the manifold distributor plate and cover plate can be made of materials such as glass, which have a much lower thermal conductivity than silicon wafers but are inexpensive and easy to process. Furthermore, glass-silicon bonding technology is mature and provides good sealing. With the development of additive manufacturing technologies such as 3D printing, the manifold distributor plate and cover plate can be manufactured as a single unit, further reducing costs. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of a manifold microchannel heat sink for high-power devices according to the present invention.

[0022] Figure 2 This is an exploded view of the manifold microchannel heat sink of the present invention, showing a flow-limiting channel arranged below the inlet manifold channel.

[0023] Figure 3 This is a schematic diagram of the assembly of the manifold distribution plate and the microchannel substrate of the manifold microchannel heat sink of the present invention.

[0024] Figure 4 This is a front view of the manifold microchannel heat sink of the present invention.

[0025] Figure 5 This is a cross-sectional view AA of the manifold microchannel heat sink cover plate of the present invention.

[0026] Figure 6 This is a cross-sectional view of the manifold distribution plate BB of the microchannel heat sink of the present invention.

[0027] Figure 7 This is a CC cross-sectional view of the microchannel substrate of the manifold microchannel heat sink of the present invention.

[0028] Figure 8 This is an exploded view of the manifold microchannel radiator of the present invention, showing a flow-limiting channel arranged below the outlet manifold channel.

[0029] Cover plate (1), manifold diverter plate (2), outlet manifold channel (3), microchannel substrate (4), microchannel (5), flow restriction channel (6), inlet reservoir (7), inlet manifold channel (8), and outlet reservoir (9); fluid inlet (10), fluid outlet (11), and rib wall (12). Detailed Implementation

[0030] This invention proposes a manifold microchannel radiator, the core idea of ​​which is: (1) The manifold channel and the flow-limiting channel work together to avoid creating a complex hierarchical manifold structure to improve the flow distribution characteristics. From a cost perspective, simplifying the manifold structure is beneficial to reducing manufacturing costs. From an efficiency perspective, simplifying the manifold structure is beneficial to reducing the pump power required for the microchannel, while improving the fluid distribution characteristics and increasing the heat exchange efficiency of the radiator. (2) The flow-limiting channel is essentially to reduce the width of the microchannel so that the flow resistance of the fluid in the microchannel is greater than that in the manifold channel. In addition to improving the flow distribution characteristics, in single-phase heat dissipation applications, arranging it below the outlet manifold channel can enhance the heat exchange efficiency and further improve the wall temperature distribution characteristics. In two-phase heat dissipation applications, arranging it below the inlet manifold channel can suppress boiling instability. In summary, the new manifold microchannel radiator can improve the disadvantage of uneven fluid distribution in conventional manifold microchannel radiators in a small size, and can also enhance single-phase and two-phase heat exchange. From a practical point of view, fewer components are beneficial to enhancing sealing and reducing the risk of working fluid leakage.

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] like Figures 1-3 The diagram shows a novel manifold microchannel heat sink. The overall structure, from top to bottom, includes a 7740 heat-resistant glass cover plate (1), a silicon manifold distribution plate (2), and a silicon microchannel substrate (4). Deionized water is used as the working fluid. The 7740 heat-resistant glass cover plate (1) and the silicon manifold distribution plate (2) have the same dimensions. The silicon microchannel substrate (4) has the same planar dimensions as the cover plate (1) and the silicon manifold distribution plate (2), but its height depends on the thickness of the silicon wafer. The silicon wafer thickness for processing the silicon microchannels using etching technology is approximately 0.3–0.4 mm. A cross-sectional area of ​​approximately 0.5 mm² is processed on the 7740 heat-resistant glass cover plate (1). 2 The rectangular or circular through holes serve as the fluid inlet (10) and fluid outlet (11), respectively. If the manifold microchannel radiator involved in the invention is designed for cooling a single heat source, a circular through hole is generally used as the fluid inlet to facilitate the connection of the radiator to the external liquid supply pipeline; however, if the manifold microchannel radiator is used as a unit of the cold plate to cool a multi-heat source system, using a rectangular through hole as the fluid inlet helps to reduce the impact of assembly errors.

[0034] The silicon manifold distribution plate (2) includes an inlet reservoir, an inlet manifold channel, an outlet reservoir, and an outlet manifold channel. Since the leftmost inlet manifold channel (8) supplies liquid to only one manifold microchannel unit, its width is only half the width of the other three inlet manifold channels, based on the principle of constant cross-sectional flow velocity. Similarly, the overall width of the inlet reservoir (7) is approximately 1–2 mm, but the width of the reservoir corresponding to the leftmost inlet manifold channel (8) is halved. Similar to the distribution system, the rightmost outlet manifold channel (3) collects the heated working fluid from only one manifold microchannel unit; therefore, its width is only half the width of the other three outlet manifold channels (3), and the corresponding outlet reservoir width is also halved. The microchannel heat dissipation area of ​​the silicon microchannel substrate is consistent with the size of the device requiring heat dissipation. The microchannel heat dissipation area comprises a series of microchannel heat exchange units consisting of microchannels (5) and current-limiting channels (6). The width of the microchannel is generally 0.15 to 0.35 times the thickness of the silicon wafer, and the width of the current-limiting channel is 0.33 to 0.5 times the width of the microchannel. The length of the current-limiting channel is equal to the width of the manifold channel. The height of the microchannel and the current-limiting channel depends on the thickness of the silicon wafer and is generally 0.67 to 0.75 times.

[0035] Based on the above structural parameters, and using deionized water as the working fluid, the flow path of the working fluid is further described: Deionized water flows from the inlet (10) into the inlet storage tank (7) through the external pipeline, increasing the flow area and decreasing the flow velocity; subsequently, the deionized water flows evenly into the inlet manifold channel (8). Due to the presence of the flow-limiting channel (6), the flow resistance in the microchannel increases, eliminating the inertial effect and causing the flow rate of deionized water in the microchannel near the radiator outlet (11) to be much greater than that in the microchannel near the inlet (10); during the process of the deionized water flowing through the microchannel (5), it continuously absorbs heat from the wall surface, ensuring that the waste heat generated by the "self-heating" effect during the device operation is promptly discharged from the device; after the temperature is raised, the fluid flows vertically into the outlet manifold channel (3) and mixes in the outlet storage tank (9), and finally flows out of the radiator through the fluid outlet (11).

[0036] Deionized water is evenly distributed into the microchannels via a manifold structure, reducing the flow velocity and flow length within the channels to one-seventh of their original values. The pressure drop within the microchannels is directly proportional to both the flow velocity and flow length. Therefore, the pressure drop within the novel manifold microchannel heat sink is significantly reduced, which is of great significance for reducing pump power consumption and further minimizing the size of the device's heat dissipation system.

[0037] Numerical simulations revealed that when the overall flow rate of the radiator is 1.5–2 g / s and the heat flux density is 300 W / cm³, 2At that time, the maximum wall temperature of a conventional manifold microchannel reached as high as 67°C, and the average temperature was also above 47°C. However, after placing the flow-limiting channel below the inlet manifold channel, the maximum temperature decreased by about 25%, the average temperature decreased by about 12%, and the maximum temperature difference of the heating surface decreased by 50%. This is mainly because the flow-limiting channel inside the microchannel improves the drawback of uneven flow distribution. Specifically, the flow difference between the first and last microchannels is reduced from 10... -2 g / s decreased to 10 -3 On the order of g / s.

[0038] Furthermore, such as Figure 8 As shown, the flow-limiting channel (6) is arranged below the outlet manifold channel (3) with the same dimensions, and the flow distribution characteristics are basically the same as in the above case. However, when the flow-limiting channel (6) is arranged below the outlet manifold channel (3), the hydraulic diameter of the channel suddenly shrinks and the flow velocity increases during the flow of deionized water. Under the condition that the overall pressure drop in the microchannel remains unchanged, the heat transfer coefficient increases and the wall temperature drops rapidly. The numerical simulation results show that compared with the flow-limiting channel (6) being arranged below the inlet manifold channel (8), the maximum temperature difference of the heating surface is reduced by 50%.

[0039] Furthermore, under the optimized structure of this invention, the narrower the flow-limiting channel, the better the heat transfer performance, but the pressure drop is slightly higher compared to the unlimited flow channel (6). For example, for a heat dissipation unit, when the width of the flow-limiting channel is reduced to one-third of the microchannel, the pressure drop increases by 50%. To address the above situation, a slightly wider flow-limiting channel is arranged in the microchannel near the inlet, and a slightly narrower flow-limiting channel is arranged in the microchannel near the outlet, forming a non-uniform width flow-limiting microchannel. On the one hand, increasing the width of the flow-limiting channel near the inlet can increase the flow rate in the channel, further improving the problem of uneven flow distribution; on the other hand, by increasing the width of the flow-limiting channel near the inlet, the flow velocity in the flow-limiting channel is reduced, thereby reducing local friction loss and helping to reduce pump power consumption. Numerical simulation results show that, with the deionized water flow rate and inlet temperature remaining constant, using a non-uniform width flow-limiting channel, compared to Figure 8 Compared to the previous structure, the maximum temperature difference of the heating surface is reduced by 25%, and the pressure drop is reduced by 7%.

[0040] Example 2

[0041] Boiling and flowing within microchannels can dissipate extremely high heat flux under very small temperature differences. When the temperature of the organic working fluid entering the microchannel is much lower than its saturation temperature, both the sensible and latent heat of the working fluid can be used to absorb waste heat from the device, ensuring its long-term safe and stable operation. For example... Figures 2-3 As shown, in Scheme 1, the flow-limiting channel (6) is arranged below the inlet manifold channel (8) to ensure uniform fluid distribution. Based on this, Scheme 2 of the present invention is proposed:

[0042] Using low-boiling-point refrigerants such as HFE-7100 as the working fluid, the flow path is completely consistent with that of Implementation Scheme 1. It should be emphasized that the flow-limiting channel (6) is located directly below the inlet manifold (8), and the length of the flow-limiting channel (6) is equal to the width of the inlet manifold channel (8). The flow-limiting channel is located at the inlet, which on the one hand ensures the uniformity of flow distribution, suppresses the boiling instability between channels caused by uneven flow distribution between microchannels, and avoids the problem of the inner wall of the low-flow microchannel drying out, thereby reducing the critical heat flux density; on the other hand, studies have shown that appropriately reducing the temperature of the working fluid entering the microchannel radiator, although beneficial to enhancing heat transfer, will cause serious boiling instability. The flow-limiting channel located at the inlet reduces the compressible space upstream of the microchannel, suppresses boiling instability, and avoids large fluctuations in pressure drop and heating surface temperature.

[0043] Numerical simulation results show that when a current-limiting channel (6) is arranged at the microchannel inlet and its width is only one-third of the microchannel width, the average temperature of the heating surface decreases by approximately 4.3%. The maximum temperature difference of the heating surface is much lower than 5℃. This will effectively reduce the thermal stress of the device and extend its service life.

[0044] In summary, the above are merely some embodiments and parameters of the present invention, intended only to more clearly explain the content of the present invention, and are not intended to limit the scope of protection of the present invention. Any modifications and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A manifold microchannel radiator with low thermal resistance, low pump power, and good stability, characterized in that, It includes a cover plate (1), a manifold distribution plate (2) and a microchannel substrate (4) in sequence. The cover plate (1) covers the manifold distribution plate (2), and the manifold distribution plate (2) covers the microchannel substrate (4) directly above it. The cover plate (1) is machined with a fluid inlet (10) and a fluid outlet (11) for connection with an external pipeline. The manifold diverter plate (2) is machined with an inlet reservoir (7), an inlet manifold channel (8), an outlet manifold channel (3), and an outlet reservoir (9). The manifold diverter plate (2) is connected vertically at corresponding locations of the inlet reservoir (7), the inlet manifold channel (8), the outlet manifold channel (3), and the outlet reservoir (9). The inlet reservoir (7) and the outlet reservoir (9) are separated by a bent baffle wall (12). On the side corresponding to the inlet reservoir (7), the bent baffle wall (12) is... Four parallel channels are formed between them, namely four inlet manifold channels (8), which are connected to the inlet storage tank (7); four parallel channels are formed between the ribs (12) that bend and deflect the flow on the side of the outlet storage tank (9), namely four outlet manifold channels (3), which are connected to the outlet storage tank (9); the outlet manifold channels (3) and the inlet manifold channels (8) are arranged in parallel and intersecting order, and the outlet manifold channels (3) and the inlet manifold channels (8) are separated by ribs (12); The fluid inlet (10) and outlet (11) on the cover plate (1) correspond to the inlet liquid storage tank (7) and outlet liquid storage tank (9) on the manifold distribution plate (2) and are connected to each other; The microchannel substrate (4) includes microchannel regions (5) and current-limiting channel regions (6) arranged in parallel and intersecting order. At both ends of the microchannel regions (5) and current-limiting channel regions (6), there are planar structures without microchannels. The microchannel regions (5) are composed of multiple parallel microchannels, and the current-limiting channel regions (6) are composed of multiple parallel current-limiting channels. The intersecting direction of the microchannel regions (5) and current-limiting channel regions (6) is consistent with the length direction of the microchannels and the length direction of the current-limiting channels. The current-limiting channel regions (6) are located in the inlet manifold channel (8). The length of each flow-limiting channel in the flow-limiting channel area (6) is equal to the width of the inlet manifold channel (8), and the length direction of the flow-limiting channel is perpendicular to the width of the inlet manifold channel (8). The ribs (12) of the outlet manifold channel (3) and the outlet manifold channel (8) and the area below the outlet manifold channel (3) correspond to the microchannel area (5). The areas below the inlet reservoir (7) and the outlet reservoir (9) correspond to the planar structures at both ends of the microchannel area (5) and the flow-limiting channel area (6) on the microchannel substrate (4).

2. A manifold microchannel radiator with low thermal resistance, low pump power, and good stability according to claim 1, characterized in that, The width of the microchannels in the microchannel region (5) is greater than the width of the flow-limiting channel in the flow-limiting channel region (6), and the spacing of the microchannels in the microchannel region (5) is less than the spacing of the flow-limiting channel in the flow-limiting channel region (6).

3. A manifold microchannel radiator with low thermal resistance, low pump power, and good stability according to claim 1, characterized in that, Four inlet manifold channels (8), three of which are of equal width, and the other one on the side is narrower, being half the width of the three above; four outlet manifold channels, three of which are of equal width, and the other one on the side is narrower, being half the width of the three above; the narrower inlet manifold channel (8) and the narrower outlet manifold channel are respectively located on both sides of the manifold splitter plate (2).

4. A manifold microchannel radiator with low thermal resistance, low pump power, and good stability according to claim 1, characterized in that, The microchannel region of the microchannel substrate (4) is the same size as the power device that needs to be cooled.

5. The operating method of a manifold microchannel radiator with low thermal resistance, low pump power, and good stability according to any one of claims 1-4, characterized in that, After the cover plate (1), the manifold distribution plate (2) and the microchannel substrate (4) are bonded together, they are connected to the liquid supply system to form a sealed system; the flow path of the fluid in the microchannel radiator is as follows: fluid inlet (10), inlet reservoir (7), inlet manifold channel (8), flow restriction channel area (6), microchannel area (5), outlet manifold channel (3), outlet reservoir (9) and fluid outlet (11); the fluid enters the manifold distribution plate (2) through the fluid inlet (10) on the cover plate (1); the manifold distribution plate includes the inlet reservoir (7), inlet manifold channel (8), outlet manifold channel (3) and outlet reservoir (9), wherein the inlet manifold channel (8) and the outlet manifold channel (3) are separated by ribs; the fluid entering the radiator from the fluid inlet (10) enters the inlet reservoir (7) and enters the outlet manifold channel (9). Four inlet manifold channels (8); due to the obstruction of the manifold ribs, the fluid in the inlet manifold channel (8) flows downward into the flow-limiting channel area (6) driven by the micro pump outside the fluid inlet (10); subsequently, the fluid is obstructed by the base of the microchannel substrate (4), and the fluid turns 90° and flows in the microchannel area (5) in a direction perpendicular to the inlet manifold channel (8); then, in the microchannel directly below the outlet manifold channel (3), the fluid is obstructed by the wall surface of the ribs or the fluid, turns 90° again, flows vertically upward out of the microchannel area (5), and enters the outlet manifold channel (3); finally, because the four outlet manifold channels (3) are connected to the outlet reservoir (9), the fluid flowing into the outlet manifold channel (3) gathers in the outlet reservoir (9) and flows out of the microchannel radiator from the fluid outlet (11).

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