High-integration electronic device micro-channel radiator

Abstract

The invention provides a high-integration electronic device micro-channel radiator. The high-integration electronic device micro-channel radiator comprises a bionic fish scale type micro-channel structure, a gas-liquid separation membrane, a micro-channel radiator protection shell, an insertion type liquid baffle, a lead screw control plug pin and a supporting plug pin. The bionic fish scale type micro-channel structure is attached to the upper side of the chip by adopting a semi-coated structure; the gas-liquid separation membrane is arranged at the top of the micro-channel structure and is in sealed connection with the micro-channel heat dissipation device protection shell; the plug-in liquid baffle is arranged at the front section of the micro-channel, and the axial position of the plug-in liquid baffle is adjusted through the lead screw control plug and the supporting plug. Primary separation is achieved through a stepped bionic structure, secondary separation is achieved by combining a hydrophobic membrane and negative pressure, and bubble blockage is thoroughly prevented. The micro barb array destroys the continuity of a gas film, and the gas leading-out efficiency is remarkably improved. The adjustable baffle supports high / low thermal load mode switching, and the robustness of the system is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heat sinks, and in particular relates to a micro-channel heat sink for high-integration electronic devices. BACKGROUND

[0002] With the rapid development of microelectronic technology, the integration of electronic devices is continuously improved, and the heat flux density is rapidly rising. Research shows that the reliability of electronic devices will decrease by 50% for every 10℃ increase in operating temperature, and more than 55% of electronic device failures are caused by overheating. Traditional air cooling has been difficult to meet the heat dissipation needs of high-power-density chips (such as CPUs, GPUs, and AI accelerators), and micro-channel heat sinks in liquid cooling technology have become a research hotspot due to their small size, strong heat transfer, and low power consumption.

[0003] However, existing micro-channel heat sinks generally have the following problems under high heat flux density conditions:

[0004] Severe bubble blockage: The cooling medium is prone to form bubble flow, plug flow, or even choked flow when phase change occurs in the micro-scale channel, leading to local dryout and burnout;

[0005] Weak gas-liquid separation capability: Lack of effective gas-liquid separation mechanism, gas and liquid mixed flow, reducing heat transfer efficiency;

[0006] Poor system stability: Unable to dynamically adjust the outlet state to adapt to the transient thermal load changes of the chip;

[0007] Poor exhaust: Gas accumulation causes back pressure to rise, affecting circulation stability.

[0008] Chinese patent CN114069035A proposes a corrugated micro-channel structure that can enhance disturbance but does not solve the gas-liquid separation problem; CN112529945A discloses a structure with a gas-liquid separation chamber, but its separation efficiency is limited and the structure is complex. Therefore, there is an urgent need to develop a new type of micro-channel heat sink that can achieve efficient gas-liquid separation and has self-adaptive capability. SUMMARY

[0009] The purpose of the present application is to provide a micro-channel heat sink for high-integration electronic devices, which solves the problems of heat transfer deterioration caused by bubble blockage, low gas-liquid separation efficiency, and poor system adaptability in the prior art, and realizes efficient, stable, and low-energy-consumption cooling of high-integration electronic devices under high heat flux density.

[0010] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0011] A high-integration electronic device micro-channel radiator mainly comprises: a bionic fish scale type micro-channel structure, a gas-liquid separation membrane, a micro-channel radiator protection shell, an inserted liquid baffle, a screw control latch and a support latch. The micro-channel structure is semi-covered and attached to the upper side of the chip, and is periodically arranged by a plurality of bionic fish scale structure units to form a stepped drop flow path; the gas-liquid separation membrane is conformally covered on the top of the micro-channel and realizes selective gas permeation under the driving of negative pressure; the opening degree of the liquid baffle can be adjusted by the screw control latch to realize the switching of the gas phase or gas-liquid two-phase discharge mode.

[0012] Preferably, the bionic fish scale structure unit comprises two-side symmetrical circular arc structures and a middle sector structure, and the opening direction of the sector structure is countercurrently arranged to promote bubble separation.

[0013] Preferably, there is a vertical drop d3 between adjacent structure units, and there is a drop d2 between the circular arc and the sector plane in the same unit, and the surface inclination angle θ is combined to strengthen the primary gas-liquid separation.

[0014] Preferably, the gas-liquid separation membrane is a biaxially stretched PTFE porous membrane, the micropores have a 'fibril-node' interlaced structure, have acid and alkali resistance and high temperature resistance characteristics, and are tightly attached to the surface of the micro-channel through a negative pressure assembly process.

[0015] Preferably, the gas-liquid separation membrane is provided with a micro barb array structure on the side facing the fluid to pierce the accumulated gas film and improve the gas exhaust efficiency.

[0016] Preferably, the protection shell is provided with an inverted triangular pyramid gas flow guide structure on the inner wall to guide the gas flow to the top exhaust port.

[0017] Preferably, the inserted liquid baffle can be adjusted according to the phase change ratio to realize self-adaptive control of working conditions.

[0018] The present application has the following advantages:

[0019] Dual gas-liquid separation mechanism: one separation is realized through the stepped bionic structure, and the second separation is realized by combining the hydrophobic membrane and negative pressure to completely prevent bubble blockage;

[0020] Active membrane breaking design: the micro barb array destroys the continuity of the gas film, and significantly improves the gas export efficiency;

[0021] Strong working condition self-adaptive ability: the adjustable baffle supports high / low heat load mode switching to improve the system robustness;

[0022] Compact structure and high integration: the semi-covered design adapts to the modern chip packaging space;

[0023] Low energy consumption and quiet operation: relying on natural density difference and negative pressure driving, no additional pump power is needed, and the noise is small;

[0024] High reliability: The inverted triangular flow guide structure prevents backflow, and the sealing assembly process ensures long-term stability. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0026] Figure 2 This is a schematic diagram of a chip mounted on a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0027] Figure 3 This is an isometric side view of the interior of a microchannel heat sink for a highly integrated electronic device before an explosion, as per this invention application.

[0028] Figure 4 This is an isometric side view of the interior of a microchannel heat sink for a highly integrated electronic device after an explosion, as per this invention application.

[0029] Figure 5 This is an isometric side view of a microchannel heat sink inside a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0030] Figure 6 This is a partial enlarged view of the microchannel heat sink inside a microchannel heat sink for a highly integrated electronic device, as described in this invention application.

[0031] Figure 7 This is a rear isometric side view of a microchannel heat sink inside a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0032] Figure 8 This is a side cross-sectional view of the heat sink inside a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0033] Figure 9 This is a schematic diagram of the internal structure of a biomimetic fish-scale-shaped microchannel for a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0034] Figure 10 This is a magnified view of a partial surface of the gas-liquid separation membrane inside a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0035] Figure 11 This is a schematic diagram of the internal gas guiding structure of a microchannel heat sink protective shell for a highly integrated electronic device, as per this invention application.

[0036] Figure 12 This is a structural view of a liquid baffle for circulating control in a microchannel heat sink for a highly integrated electronic device, as per this invention application.

[0037] Figure 13It is a high-integration electronic device micro-channel radiator micro-channel fin side inverted ladder form cross-section structure view for the application.

[0038] Figure 14 It is a high-integration electronic device micro-channel radiator working flow chart for the application.

[0039] Figure 15 It is a high-integration electronic device micro-channel radiator fish scale type high-low difference gas-liquid separation schematic diagram for the application.

[0040] A, required heat dissipation chip; B, high-integration electronic device micro-channel radiator; 1, bionic fish scale type micro-channel fin; 11, micro-channel fin front section water outlet; 12, bionic fish scale type micro-channel fin inner bionic fish scale structure; 121, bionic fish scale type micro-channel fin inner bionic fish scale structure two side arc structure; 122, bionic fish scale type micro-channel fin inner bionic fish scale structure fan-shaped fish scale structure; 123, bionic fish scale type micro-channel fin upward angle structure; 13, bionic fish scale type micro-channel side inverted ladder form structure; 131, bionic fish scale type micro-channel inverted ladder form structure upper side; 132, bionic fish scale type micro-channel inverted ladder form structure base surface; 14, micro-channel fin semi-enclosed type structure; 15, micro-channel lower side multiple water inlet structure; 16, micro-channel fin semi-enclosed structure outer wall surface; 17, circulating control liquid baffle mounting hole; 2, gas-liquid separation membrane; 21, gas-liquid separation membrane micro inverted spine array structure; 211, micro inverted spine arc base; 212, micro inverted spine front section sharp angle extension structure; 3, micro-channel radiator protection shell; 31, micro-channel radiator protection shell upper side exhaust port; 32, micro-channel radiator protection shell U-shaped semi-enclosed connection structure; 33, micro-channel radiator protection shell inner gas guiding structure; 331, micro-channel radiator protection shell inner gas guiding structure gas-liquid separation membrane butt joint surface; 332, micro-channel radiator protection shell inner gas guiding structure gas guiding surface; 4, circulating control liquid baffle structure; 41, lead screw thread hole; 42, latch support hole; 5, lead screw control latch; 6, support latch. DETAILED DESCRIPTION

[0041] The specific embodiments of the application are described below in conjunction with the accompanying drawings. It should be understood that these embodiments are only used to explain the application, and not to limit the protection scope thereof. Any equivalent replacement or improvement made according to the technical solutions of the application shall be included in the protection scope of the application.

[0042] In one embodiment of the application, as shown in Figures 1 to 15As shown, the present invention provides a microchannel heat sink for highly integrated electronic devices, mainly comprising six core components: a biomimetic fish-scale-shaped microchannel heat sink 1, a gas-liquid separation membrane 2, a protective shell for the microchannel heat sink 3, an adjustable liquid baffle 4, a lead screw control pin 5, and a support pin 6. The biomimetic fish-scale-shaped microchannel heat sink adopts a semi-enclosed structure and is attached to the chip surface, achieving direct cooling through convection heat transfer; the gas-liquid separation membrane is attached to the outside of the microchannel, constructing a gas-liquid separation interface; the microchannel protective shell supports the overall structure; the liquid baffle can be height-adjusted via a lead screw structure; the lead screw control pin and the support pin together constitute a lifting control system.

[0043] The components in the above embodiments of this application work together to form a closed, stable, and controllable two-phase flow boiling cooling system, which is suitable for the high-efficiency heat dissipation requirements of high-power-density electronic devices.

[0044] In one embodiment of this application, a heat dissipation working principle is provided. Specifically, the heat generated during chip operation is transferred to the inner wall of the microchannel heat sink through thermal conduction and then longitudinally conducted to the outer wall. A low-temperature cooling medium flows into the microchannel from the substrate end inlet at a predetermined speed, flowing from top to bottom along the substrate surface. During forced convection heat transfer, it absorbs heat, thereby cooling the chip. When the cooling medium flows through the high-temperature region and heats up to its boiling point, a phase change occurs, generating bubbles. Under the action of the flow field, the bubbles are guided by the two side arc structures and the central fan-shaped structure within the biomimetic fish-scale-shaped microchannel. The gas-liquid separation membrane is a PTFE microporous hydrophobic membrane. Under the action of the negative pressure zone formed between the microchannel protective shell and the hydrophobic membrane, the bubbles migrate towards the inner surface of the membrane due to adsorption force. When the bubbles contact the membrane surface, they are pierced and ruptured by the micro-barb array structure on its surface, releasing internal gas and seeping out through the hydrophobic membrane, thus achieving gas-liquid separation. The separated gas enters the gas collection chamber inside the protective shell, is concentrated by the gas guiding structure, and is discharged from the top rectangular exhaust port. In addition, the opening of the liquid baffle can be adjusted according to the degree of vaporization of the cooling medium when it reaches the bottom layer: if it is completely vaporized, the outlet is closed; if there is still liquid phase residue, the opening is adjusted according to the remaining amount, which effectively controls the liquid flow rate per unit time and prevents the formation of blockage flow.

[0045] The embodiments described above in this application significantly improve gas-liquid separation efficiency through a three-in-one mechanism of structural guidance, negative pressure drive, and barbed membrane rupture, avoiding heat transfer deterioration caused by bubble accumulation in traditional microchannels.

[0046] In one embodiment of this application, a design source for a biomimetic fish-scale microchannel structure is provided. Specifically, this invention draws inspiration from the fluid diversion, convergence, and collision mechanisms in Tesla valves to design a biomimetic fish-scale microchannel structure with enhanced heat transfer capabilities on the basis of the same heat transfer area. This structure enhances perturbation through geometric induction, promotes boundary layer renewal and nucleate boiling, and is suitable for high heat flux density scenarios.

[0047] The embodiments described above in this application introduce an asymmetric flow channel design concept to improve the local heat transfer coefficient, while utilizing structural characteristics to achieve passive gas-liquid separation.

[0048] In one embodiment of this application, specific geometric parameters for a biomimetic fish scale unit are provided. Specifically, such as... Figure 9 As shown, the biomimetic fish scale-shaped microchannel structure is composed of two side arc structures 122 and a central fan-shaped structure 123.

[0049] The two circular arc structures 122 are geometrically tangent to the central axis of the single microchannel, with a radius R1 = 3.6 mm and a center offset from the central axis by 7 mm, arranged symmetrically about the central axis. The central fan-shaped structure 123 has a radius R2 = 2.4 mm, and its center is located on the central axis, horizontally offset by 2.67 mm from the center of the two circular arc structures. The fan-shaped opening points in the opposite direction of the cooling medium flow. During the research and development process, the effects of R1 and R2 on the Nusselt number (Nu) and friction factor (f) in the Re=400–900 range were studied through numerical simulation. Finally, it was determined that the combination of R1=3.6 mm and R2=2.4 mm has the best comprehensive thermodynamic performance.

[0050] The geometric parameters optimized by simulation in the above embodiments of this application can maximize heat transfer efficiency while ensuring low pressure drop, making them suitable for engineering mass production.

[0051] In one embodiment of this application, structural parameters for a single microchannel are provided. Specifically, the total length of a single biomimetic fish-scale-shaped microchannel is 40 mm, and its width is 4.6 mm. Each structural unit includes two symmetrical arc structures 122 and a central fan-shaped structure 123. The planes containing the two arc structures are at the same height and are aligned with the vertical normal direction; there is a vertical drop d2 = 0.268 mm between this plane and the plane containing the central fan-shaped structure.

[0052] There is a vertical drop d3 = 0.5375 mm between adjacent structural units; the height of each unit starts from the initial value of 4.3 mm and decreases in increments of 0.5375 mm, and after 8 decreases, it is level with the base surface.

[0053] The stepped drop structure of the above embodiments of this application causes the cooling working fluid to produce a "step-by-step drop" effect during flow, which enhances the turbulence intensity. At the same time, gravity is used to make the bubbles float to the surface, thus achieving gas-liquid separation.

[0054] In one embodiment of this application, such as Figure 8 As shown, the inclination angle θ between the surface of the biomimetic fish-scale microchannel structure and the horizontal plane is between 2° and 6°. This inclination angle further increases the effective height difference between the structural units, enhancing the separation tendency of the gas and liquid phases due to density differences.

[0055] The above embodiments of this application can significantly improve the bubble rising path by slight tilting, reduce the probability of gas phase backmixing, and improve separation efficiency.

[0056] In one embodiment of this application, an inverted trapezoidal cross-section structure is provided. For example... Figure 13 As shown, the biomimetic fish-scale microchannel features an inverted trapezoidal cross-sectional structure on its sides, with the cross-sectional area decreasing along the height direction from the base to the front, forming a tiered structure. The base height of the tier is 5.4 mm; the front height is 1.87 mm; and the overall structure has a linear inclination angle of 5°. This design helps to compress the upper gas phase space, forcing the gas to accumulate upwards.

[0057] The embodiments described above reduce gas phase flow resistance, improve gas-liquid separation efficiency, and reduce circulating pressure loss.

[0058] In one embodiment of this application, an optimized design for a semi-enclosed mounting structure is provided. A biomimetic fish-scale-shaped microchannel heat sink has a semi-enclosed structure on the side facing away from the fluid channel, which is precision-machined to form an integral structure with the main body. This structure defines a rectangular enclosed cavity with the following three-dimensional dimensions: Length: 400 mm ± 0.05 mm; Width: 400 mm ± 0.05 mm; Depth: 2 mm ± 0.05 mm. The four sidewalls of the enclosed cavity form contact-type thermally conductive connections with the corresponding sidewalls of the chip, ensuring good thermal coupling. This structure facilitates the stable mounting of the heat sink on the upper side of the chip and achieves all-around heat dissipation coverage.

[0059] The large-size encapsulation structure described in the above embodiments of this application is adapted to high-performance computing chips (such as GPUs and AI accelerators), improving installation reliability and heat dissipation uniformity.

[0060] In one embodiment of this application, the liquid inlets are arranged with multiple channels. Nine rectangular liquid inlets are evenly distributed along the edge of the substrate, each with dimensions of 4 mm ± 0.1 mm in length and 1.1 mm ± 0.05 mm in width. A total of nine microchannels are arranged in a horizontal array, with adjacent channels spaced 5.6 mm apart, ensuring complete coverage of the chip surface by the heat dissipation area. A thin baffle with a thickness of 1 mm ± 0.05 mm separates two microchannels to prevent fluid crosstalk. The top of the microchannels is sealed and covered by a PTFE microporous hydrophobic membrane and a protective shell, forming a closed vapor exhaust interface, achieving gas-liquid separation during operation.

[0061] The multi-channel parallel design of the above embodiments of this application ensures flow uniformity, and the thin partition improves structural rigidity and prevents vibration failure.

[0062] In one embodiment of this application, a gas-liquid separation membrane material and assembly process are provided. The PTFE microporous hydrophobic membrane has a thickness of 50 μm and is manufactured through a biaxial stretching process. The micropores exhibit a "fiber-node" interwoven morphology, possessing resistance to strong acids, strong alkalis, and high temperatures. During assembly, a negative pressure of -5 to -10 kPa is applied through a pre-reserved air extraction channel in the protective shell, causing the membrane to adhere tightly to the surface of the microchannels. After sealing and curing, the pressure is removed. This membrane has the characteristic of allowing only gas to permeate; when a bubble touches its inner surface, the gas can pass through smoothly, while the liquid phase is blocked, thereby achieving gas-liquid separation.

[0063] The negative pressure pre-tightening process in the above embodiments of this application eliminates gaps and prevents leakage; the hydrophobic membrane selective permeation mechanism fundamentally solves the plunger flow blockage problem.

[0064] In one embodiment of this application, a micro-barb array structure and its working mechanism are provided. Figure 10 As shown, a micro-barb array structure is disposed on the side of the PTFE microporous hydrophobic membrane facing the microchannel fluid. This structure is composed of several conical needle-like units arranged periodically, with specific parameters as follows:

[0065] - The radius of curvature of the spike tip r ≤ 1 μm;

[0066] - Spike height h1 = 5–15 μm;

[0067] - The diameter of the base of the thorn root is d = 2–8 μm;

[0068] - Array height h2 = 10–30 μm;

[0069] - Surface density is 10 4 -10 6 pcs / cm²;

[0070] - Its tip extends into the microchannel.

[0071] Because the gas inside the bubble is protected by the liquid film, it is difficult for it to directly penetrate the hydrophobic membrane. When the bubble approaches the membrane surface, it will be punctured by the barbs and burst, releasing the gas and allowing it to escape smoothly.

[0072] The barbed structure in the above embodiments of this application can disrupt bubble stability and overcome the "air film shielding effect", thereby significantly improving exhaust efficiency.

[0073] In one embodiment of this application, a microchannel protective shell structure is provided. The protective shell of this microchannel heat dissipation device has a U-shaped cavity structure, covering the sides and bottom of the microchannel heat sink to form an internal chamber for receiving gas. Its upper wall thickness is 1 mm, the left and right side walls are 2.5 mm thick, and the front and rear side walls are 1 mm thick. After docking with the microchannel heat sink, a PTFE membrane in the middle separates the upper negative pressure chamber from the lower cooling medium area.

[0074] The differentiated wall thickness design adopted in the above embodiments of this application takes into account both the lightweight structure and the overall strength, thereby ensuring the reliability of the device in long-term operation.

[0075] In one embodiment of this application, a gas guiding structure and an exhaust port are designed. Inverted triangular cone-shaped gas guiding structures are provided on both sides of the inner wall of the protective shell.

[0076] The mating surfaces are parallel to the PTFE membrane, with a spacing of 1 mm.

[0077] The gas guiding surface forms a 50° angle with the vertical plane;

[0078] The upper side connects to a rectangular exhaust port (8.5 mm × 4.5 mm).

[0079] This structure concentrates and guides the dispersed gas to the exhaust port, accelerating its discharge.

[0080] The embodiments described above in this application efficiently guide airflow to avoid gas stagnation and maintain stable low-pressure operation of the system.

[0081] In one embodiment of this application, a liquid baffle adjustment system is designed. A cooling medium circulation adjustment system is installed at the microchannel front-end outlet, consisting of a liquid baffle 4, a lead screw control pin 5, and a support pin 6. The liquid baffle has a rectangular structure with a height of 4 ± 0.05 mm. Cylindrical pins with a radius of 0.75 mm are provided at both ends, and a 1 mm diameter through hole is located in the center. One side has a threaded hole, and the other side has a smooth hole. The height of the baffle can be adjusted by rotating the lead screw control pin, thereby controlling the outlet opening.

[0082] The embodiments described above dynamically adjust the system based on the degree of vaporization to prevent drying out or excessive emissions and improve system adaptability.

[0083] In one embodiment of this application, an optimized design for the lead screw and support pin is provided. The lead screw control pin has a lower end round pin with a length of 7 mm, a diameter of 1 mm, and a threaded section length of 6 mm, which mates with the threaded hole of the baffle to form a lead screw drive.

[0084] Support pin: The lower end round pin is 7 mm long and 1 mm in diameter, with a smooth cylindrical structure, providing only support and balance. A single-sided lead screw + single-sided support structure simplifies adjustment.

[0085] The above embodiments of this application have a compact structure, smooth adjustment, and avoid the synchronization problems caused by dual lead screws.

[0086] In some specific embodiments of this application, a specific workflow for a microchannel heat sink for highly integrated electronic devices is provided, such as... Figure 14 and Figure 15 As shown.

[0087] This radiator uses the boiling and flowing of the cooling fluid as its core heat transfer method, combined with a biomimetic fish-scale stepped structure for primary gas-liquid separation (corresponding to...). Figure 15 Secondary gas-liquid separation with gas-liquid separation membrane (corresponding to) Figure 14 To achieve efficient heat dissipation of highly integrated electronic devices, the overall workflow can be divided into six core stages:

[0088] 1. Cooling fluid inflow stage

[0089] The low-temperature cooling medium flows in at a predetermined speed through multiple inlet structures 15 on the underside of the microchannel heat sink. The inlets are equidistantly arranged along the edge of the substrate and connected to multiple horizontally arrayed biomimetic fish-scale-shaped microchannels. The medium flows from top to bottom along the microchannel base surface, completing full coverage of the chip's heat dissipation area. At this time, the microchannel's insertable liquid baffle 4 will preset its initial opening according to the chip's thermal load, leaving room for subsequent medium flow and phase change.

[0090] 2. Convective heat transfer and phase transition stage

[0091] The heat generated during chip operation is transferred to the inner wall of the microchannel through contact heat conduction via the semi-enclosed structure 14 of the biomimetic fish-scale-shaped microchannel structure 1. The low-temperature cooling medium absorbs heat during forced convection heat transfer, causing its temperature to rise continuously. When the working medium flows through the high-temperature region of the chip and reaches its boiling point, a phase change occurs, generating a large number of bubbles and forming a gas-liquid two-phase flow. This stage completes the initial cooling of the chip (corresponding to...). Figure 14 The process involves "convective heat transfer", "heating phase change", and "gas generation".

[0092] 3. Primary gas-liquid separation (stepped structure driven)

[0093] As bubbles flow with the working fluid within the biomimetic fish-scale-shaped microchannel, the first gas-liquid separation is achieved through the stepped flow path (corresponding to...). Figure 15 ):

[0094] The vertical height difference between adjacent biomimetic fish scale structure units, the planar height difference between the arc structure and the central fan-shaped structure within the same unit, and the overall tilt setting of the microchannel at 2°~6° form a "high and low step height difference";

[0095] Utilizing the density difference between the gas and liquid phases, bubbles float and gather upwards under the guidance of gravity and flow field, while the liquid flows downwards along the steps. The counter-current opening design of the fan-shaped structure further promotes the detachment of bubbles from the liquid flow, preventing bubbles from accumulating and blocking in the channel.

[0096] 4. Secondary gas-liquid separation (membrane separation + active membrane disruption)

[0097] After initial separation, the bubbles migrate upwards to the top of the microchannel, where they undergo a second gas-liquid separation via the gas-liquid separation membrane 2 (corresponding to...). Figure 14 (The "gas expulsion from the hydrophobic layer" step)

[0098] When the bubble comes into contact with the gas-liquid separation membrane, the micro-barb array structure 21 on the side of the membrane facing the microchannel will puncture the accumulated gas membrane, break the "gas membrane shielding effect", and release the internal gas.

[0099] A negative pressure of -5 to -10 kPa is applied to the outside of the gas-liquid separation membrane, driving the gas to permeate through the hydrophobic PTFE porous membrane (which has an interwoven microporous morphology of "fiber-node"), while the liquid phase is blocked by the membrane in the microchannel and continues to participate in heat transfer, thus completing the precise separation of gas and liquid.

[0100] 5. Directional gas discharge stage

[0101] Gas passing through the gas-liquid separation membrane enters the internal chamber of the protective shell 3 of the microchannel heat dissipation device. Guided by the inverted triangular cone-shaped gas guiding structure 33 on the inner side wall of the protective shell, the gas flows from the gas-liquid separation membrane docking surface to the exhaust port 31 on the upper side of the protective shell, achieving directional and rapid discharge, avoiding gas stagnation and back pressure increase. At the same time, the guiding structure can prevent gas backflow and ensure the system circulation stability.

[0102] 6. Liquid circulation regulation stage

[0103] When the unvaporized cooling medium in the microchannel flows to the front section of the channel, the insert-type liquid baffle 4 will dynamically adjust its axial position and opening according to the phase change ratio of the cooling medium:

[0104] If the working fluid is completely vaporized, the baffle closes the outlet to prevent gas leakage;

[0105] If any liquid phase remains, the baffle adjusts its opening according to the remaining liquid volume, allowing unvaporized liquid to be discharged from the outlet 11 at the front of the microchannel heat sink and circulated back (corresponding to...). Figure 14 The process of "discharging unvaporized liquid" enables adaptive matching of the chip's transient thermal load, avoiding localized drying or excessive discharge of the working fluid.

[0106] Through the above process, the heat sink forms a closed loop of "heat transfer - phase change - two separations - gas and liquid are discharged separately", realizing efficient and stable cooling of highly integrated electronic devices under high heat flux density.

Claims

1. A microchannel heat sink for highly integrated electronic devices, characterized in that, include: The microchannel structure consists of a biomimetic fish scale shape (1), a gas-liquid separation membrane (2), a microchannel heat dissipation device protective shell (3), an insertable liquid baffle (4), a screw control pin (5), and a support pin (6). The biomimetic fish scale shape microchannel structure (1) is attached to the upper side of the chip in a semi-enclosed structure. The gas-liquid separation membrane (2) is located on the top of the microchannel structure and is sealed to the microchannel heat dissipation device protective shell (3). The insertable liquid baffle (4) is located at the front of the microchannel and its axial position is adjusted by the screw control pin (5) and the support pin (6). The biomimetic fish scale-shaped microchannel structure (1) is composed of multiple structural units arranged sequentially along the flow direction of the cooling working fluid; Each structural unit includes an arc structure (122) symmetrically arranged on both sides and a central fan-shaped structure (123) located in the central axis region. The geometric contour of the arc structure (122) is tangent to the central axis of the microchannel; The opening direction of the central fan-shaped structure (123) is opposite to the flow direction of the cooling working fluid; There is a height difference between adjacent structural units in the vertical direction, forming a stepped flow path; Within the same structural unit, there is a vertical drop between the plane where the arc structure (122) is located and the plane where the central fan-shaped structure (123) is located; The overall surface of the biomimetic fish scale microchannel structure (1) is inclined relative to the horizontal plane.

2. The microchannel heat sink according to claim 1, characterized in that, The cross-section of the biomimetic fish scale microchannel structure (1) is an inverted trapezoid, and the cross-sectional area gradually decreases from the base to the top. The gas-liquid separation membrane (2) is conformally covered on top of the microchannel structure to form a gas-liquid separation interface.

3. The microchannel heat sink according to claim 1, characterized in that: By utilizing the stepped structure of the biomimetic fish scale microchannel structure (1) and the density difference between the gas and liquid phases, the cooling working fluid achieves the first gas-liquid separation during the flow process. A negative pressure is applied to the outside of the gas-liquid separation membrane (2) to drive the gas through the hydrophobic gas-liquid separation membrane and achieve a second gas-liquid separation.

4. The microchannel heat sink according to claim 3, characterized in that, The gas-liquid separation membrane (2) is a porous film formed by biaxial stretching process, and its microporous structure presents a "fiber-node" interwoven morphology; The gas-liquid separation membrane (2) is fixed to the top of the microchannel structure by a negative pressure assembly process.

5. The microchannel heat sink according to claim 3, characterized in that, The gas-liquid separation membrane (2) has a micro barb array structure (21) on the side facing the microchannel. The micro barb array structure (21) is composed of multiple conical needle-like units arranged periodically, with the tip of each unit extending into the microchannel to disrupt the accumulated gas film and promote gas discharge.

6. The microchannel heat sink according to claim 1, characterized in that, The inner wall of the protective shell (3) of the microchannel heat dissipation device is provided with an inverted triangular cone-shaped gas guiding structure (33). One end of the inverted triangular cone-shaped gas guiding structure (33) is connected to the gas-liquid separation membrane area, and the other end is connected to the exhaust port (31) on the upper side of the protective shell, which is used to guide the directional flow of gas.

7. The microchannel heat sink according to claim 1, characterized in that, The insertable liquid baffle (4) can adjust its opening according to the phase change ratio of the cooling medium to achieve the switching of operation mode that allows only the gas phase to pass through or allows both gas and liquid phases to be discharged together.

8. The microchannel heat sink according to claim 1, characterized in that, The gas-liquid separation membrane (2), the microchannel heat dissipation device protective shell (3), and the biomimetic fish scale-shaped microchannel structure (1) together constitute a sealed cavity.

Images