Chip top cover type heat dissipation device based on phase change heat transfer mechanism

Abstract

The invention relates to a chip top cover type heat dissipation device based on a phase change heat transfer mechanism, which comprises a top cover, a jet plate, a phase change bottom plate and a core carrier plate which are sequentially stacked from top to bottom and are in sealed connection, a chip is mounted on the core carrier plate, the bottom of the phase change bottom plate is attached to the surface of the chip, the interior of the phase change bottom plate is hollow, and a first phase change cavity is formed in the interior of the phase change bottom plate; a second phase change cavity is defined between the jet flow plate and the phase change bottom plate, the top cover is provided with a top cover groove used for containing the jet flow plate, the phase change bottom plate and the chip, and the top cover is provided with a first connector and a second connector which are used for installing the connector so that inflow and outflow of the cooling working medium can be achieved. Compared with the prior art, the integrated design of cooling and heat diffusion functions is realized in a limited space, the overall heat resistance between a chip and a heat dissipation interface is effectively reduced, the working medium circulation and heat diffusion process can be accelerated, the heat dissipation efficiency and temperature uniformity of a chip area are remarkably improved, and the heat dissipation efficiency of the chip area is improved. And the compact and efficient heat dissipation requirements of the high-heat-flux chip are met.

Description

Technical Field

[0001] This invention relates to the field of electronic chip thermal management technology, and in particular to a chip top cover heat dissipation device based on a phase change heat transfer mechanism. Background Technology

[0002] With the continuous development of high heat flux density electronic chips, the heat generated per unit area continues to increase, placing higher demands on the heat transfer efficiency and temperature uniformity of heat dissipation structures. Traditional air cooling and single-phase liquid cooling technologies, due to their limited heat exchange capacity, are unable to achieve efficient heat dissipation in limited spaces and cannot meet the thermal management requirements of next-generation high-power chips.

[0003] To improve the heat dissipation capacity of heat flux density chips, two-phase heat transfer technology based on the synergistic effect of working fluid phase change heat transfer and heat diffusion has gradually become a key research and application direction. Heat dissipation devices based on two-phase heat transfer technology mainly achieve efficient heat transfer through the vaporization and condensation cycle of the working fluid, which can improve temperature uniformity to a certain extent.

[0004] However, existing two-phase heat transfer devices (such as heat pipes and vapor chambers) are typically used as independent components. When combined with a cooling substrate or chip package, additional interface thermal conductive materials or fastening structures are required, which can easily introduce large contact thermal resistance and increase the heat transfer path length, thereby reducing the overall thermal conductivity. In addition, the condensation and reflux processes inside traditional phase change chambers are limited by the confined space, making it difficult to optimize the flow loop. This results in slow condensation response and limited heat diffusion paths, making it difficult to simultaneously meet the performance requirements of high-efficiency heat exchange, compact structure, and low power consumption operation. This is not conducive to applications in high-performance computing, electronic devices, and optoelectronic packaging. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art by providing a chip top cover heat dissipation device based on a phase change heat transfer mechanism. This device can achieve an integrated design of cooling and heat diffusion functions within a limited space, accelerate the working fluid circulation and heat diffusion process, and significantly improve the heat dissipation efficiency and temperature uniformity of the chip area, thereby meeting the compactness and efficient heat dissipation requirements of high heat flux density electronic devices.

[0006] The objective of this invention can be achieved through the following technical solution: a chip top cover heat dissipation device based on a phase change heat transfer mechanism, comprising a top cover, a jet plate, a phase change base plate, and a core carrier plate stacked and sealed from top to bottom. A chip is mounted on the core carrier plate. The bottom of the phase change base plate is in contact with the chip surface. A first phase change cavity is provided in the hollow interior of the phase change base plate. A second phase change cavity is formed between the jet plate and the phase change base plate. The top cover is provided with a top cover groove for accommodating the jet plate, the phase change base plate, and the chip. The top cover is provided with a first interface and a second interface for installing connectors to realize the inflow and outflow of cooling working fluid.

[0007] The core carrier board is a circuit board used for chip mounting. The chip is usually fixed to the mounting surface of the core carrier board by soldering. The core carrier board can be a substrate structure with good thermal conductivity and electrical connection function. The core carrier board integrates an electrical wiring layer for signal transmission and power connection of the chip; at the same time, its substrate can be made of metal matrix composite material, ceramic substrate or high thermal conductivity insulating material to balance electrical insulation and thermal conductivity.

[0008] The chip can be any type of electronic chip with high heat flux density, including but not limited to central processing units, graphics processing units, field-programmable gate arrays, tensor processing units, semiconductor laser chips, optical communication chips, and other high power density electronic components. The chip can be mounted individually on the core carrier board, or integrated in the form of multi-chip modules or system-in-package to adapt to the heat dissipation requirements of different package sizes and power levels.

[0009] The chip can be in bare die form or with a package. When the chip is in bare die form, its surface can be coated or sprayed with a thermally conductive interface material, such as thermally conductive silicone grease, thermally conductive gel, thermally conductive phase change material, or a high thermal conductivity metal coating, to improve the thermal conductivity between the chip surface and the phase change substrate and reduce the interface thermal resistance. When the chip has a package, a thermally conductive interface material or thermally conductive pad can be applied to the upper surface of the package to achieve close thermal contact between the upper surface of the package and the phase change substrate, thereby ensuring stable and consistent heat dissipation performance.

[0010] The side of the phase-change substrate that contacts the chip can have raised bosses around the chip to avoid solder joints, pins, or other electronic components around the chip, thus preventing assembly interference and improving installation stability. The height of this boss structure is denoted as L, where L≥0. Its height and dimensions can be adjusted according to the chip size and the layout of surrounding components to ensure that the phase-change substrate and the chip surface are fully bonded, while maintaining the flatness and reliability of the overall structure.

[0011] Furthermore, the size, depth, and shape of the top cover recess can be adjusted according to the structural dimensions of the chip, phase change substrate, and jet plate to ensure a tight fit and reliable sealing of each component after assembly. The top cover recess can be manufactured through machining, milling, or other precision forming processes. Its size and shape can be flexibly designed and optimized according to different chip packaging forms and the structural parameters of the components it accommodates, thereby ensuring a compact structure and reliable sealing after assembly, achieving overall structural compactness and thermal contact stability.

[0012] The connection between the joint and the first and second interfaces can be achieved through threaded connections, welding, quick-connect fittings, or adhesive bonding to achieve both fixation and sealing. The type of joint can be selected based on the system interface form and installation method, including threaded joints, quick-connect fittings, clamp-type joints, or flange-type joints. The materials can be metal, stainless steel, or high-strength corrosion-resistant engineering plastics to ensure sealing and pressure resistance. A sealing ring or gasket can be installed inside the joint to prevent working fluid leakage. Elbow-type, straight-through, or rotatable structures can be designed according to the fluid channel layout to facilitate connection with pipelines of different cooling systems. Straight-through types are suitable for scenarios with straight flow connections, while elbow-type or rotatable types are suitable for situations with limited space or reversible piping. Auxiliary sealing materials such as PTFE tape, sealant, or sealing gaskets can be used at the joint connection to enhance the gas-liquid sealing performance at the interface, preventing leakage of the working fluid under high temperature or high pressure conditions, thereby ensuring the long-term stable operation of the circulation system.

[0013] In practical applications, right-angle pagoda connectors are preferred. The inlet and outlet of the right-angle pagoda connector are arranged vertically, which facilitates the turning and connection of the cooling fluid pipeline, reduces space occupation and optimizes fluid arrangement. Right-angle pagoda connectors have good sealing performance and ease of assembly. They are suitable for hose connection structures and can achieve reliable sealing through clamps or threads, further improving the stability and maintenance convenience of the system.

[0014] Furthermore, the side of the first phase change cavity in the phase change base plate closest to the chip is the evaporation end, the opposite side of the evaporation end is the condensation end, the side of the phase change base plate facing the jet plate is the enhanced heat transfer surface, the evaporation end is provided with a first micro-rib structure to enhance the phase change heat transfer of the evaporation end, and the enhanced heat transfer surface is provided with a second micro-rib structure to improve the heat transfer efficiency of the condensation end.

[0015] The first and second microrib structures can be selected as microrib columns and / or microribs. Their projected shapes in the vertical direction can be rounded rectangles, parallelograms, circles, triangles, S-shapes, ellipses, teardrop-shaped shapes, hexagons, or other irregular polygons. Their three-dimensional forms can be columns, cones, frustums, hemispheres, or umbrella-shaped structures, or any combination of the above forms. Among them, the microrib columns are usually columnar structures used to enhance local turbulence and bubble nucleation capabilities; the microribs can be continuous or discontinuous strip structures, arranged along the flow direction or at a specific angle to expand the heat exchange area and improve the fluid guidance effect. In addition, the S-shape resembles a corrugated or serpentine path, which can enhance fluid turbulence; the umbrella-shaped structure is a composite rib column with a large difference in size between the top and bottom. Its head and root can be a combination of the same or different shapes, including column, cone, or frustum structures with rectangular, trapezoidal, circular, triangular, or elliptical cross-sections. By rationally designing the geometry, size, and distribution density of the first and second micro-rib structures, the comprehensive optimization of heat transfer performance at both the evaporation and condensation ends can be achieved while taking into account both heat exchange efficiency and flow resistance.

[0016] The arrangement of the first and second microrib structures can be either linear or interleaved. Linear arrangement refers to the microrib structures being neatly arranged to form a regular array structure, which reduces the flow resistance of the working fluid and maintains flow direction stability. Interleaved arrangement refers to the staggered or alternating distribution of adjacent rows of microrib structures, which enhances the disturbance and mixing effect of the working fluid and promotes the intensification of the evaporation process of the cooling working fluid. The arrangement should be selected according to the functional requirements of different regions to achieve a coordinated optimization of flow resistance and heat transfer performance.

[0017] Furthermore, the condensing end is provided with a condensing groove, the inner surface of which is hydrophobically treated to promote the detachment and reflux of the cooling medium. By introducing a condensing groove structure at the condensing end, the cooling medium is encouraged to rapidly accumulate, detach, and reflux back to the evaporation zone along gravity and capillary action. This effectively reduces the liquid film retention effect, enhances the renewal rate of the vapor-condensate phase separation interface, and thus improves the condensation heat transfer capacity. Through the synergistic effect of the first micro-rib structure, the second micro-rib structure, and the condensing groove, the evaporation and condensation heat transfer rates inside the first phase change cavity are significantly enhanced, improving the heat diffusion efficiency and temperature distribution uniformity within the first phase change cavity, forming a stable and efficient phase change cycle process.

[0018] The inner surface of the condensation groove can be formed with hydrophobic micro / nanowire arrays, nanobumps, nanopillar arrays, or layered rough structures to induce the growth of condensate droplets in a droplet-like condensation morphology, thereby inhibiting liquid film coverage and promoting rapid droplet detachment and discharge. Through the capillary gradient and low surface energy characteristics of the micro / nano structures, spontaneous sliding, jumping, or merging and detachment of the condensate on the surface can be achieved, continuously renewing the vapor-liquid interface to enhance the phase change heat transfer at the condensation end. These micro / nano structures can be prepared by methods such as chemical etching, electrochemical deposition, laser texturing, nanoimprinting, anodizing, sputtering deposition, or sol-gel; or hydrophobic functional coatings, such as fluoride coatings, carbon-based self-assembled films, or low surface energy polymer thin layers, can be deposited on their surfaces to achieve a surface-strengthening effect for efficient condensation at the condensation end.

[0019] Furthermore, the evaporation end is covered with a first capillary layer of height h1, and the outer surface of the first microrib structure is covered with a first capillary layer of thickness d1. The total height of the first microrib structure is H1, and the total thickness of the first microrib structure is D1, where h1>0, d1>0, and 0 ≤ h1>0 ≤ d ... That is, the first capillary structure layer is located in the evaporation end region inside the first phase change cavity, and is used to maintain the stability of the capillary reflux and vaporization interface of the cooling working fluid. The enhanced heat exchange surface is covered with a second capillary structure layer with a height of h2, and the outer surface of the second microrib structure is covered with a second capillary structure layer with a thickness of d2. The total height of the second microrib structure is H2, and the total thickness of the second microrib structure is D2; wherein h2≥0, d2≥0, and 0≤h2 / H2≤100%, 0≤d2 / D2≤100%.

[0020] Specifically, when the ratio of h2 / H2 to d2 / D2 is 0, it indicates that the bottom and outer surfaces of the second microrib structure do not have a second capillary layer, and it is a smooth, solid structure. When the ratios of h1 / H1, d1 / D1, h2 / H2, and d2 / D2 are 100%, it indicates that both the first and second microrib structures are composed entirely of capillary structures. By rationally designing and controlling the height and thickness of the capillary layer, zonal optimization can be achieved at the evaporation and condensation ends, thereby adapting to the two-phase heat transfer requirements under different working fluid circulation conditions.

[0021] Furthermore, the first phase change cavity is provided with a plurality of support columns to support the cavity structure of the first phase change cavity and maintain its internal space stability. The outer surface of the support columns is covered with a third capillary structure layer and / or a liquid guiding groove to guide and promote the cooling working fluid to flow back down along the surface of the support columns to the evaporation end. ​The inner wall surface of the first phase change cavity is covered with a fourth capillary structure layer. The inner surface of the condensation groove is not provided with a fourth capillary structure layer to maintain the hydrophobic properties of the area. The fourth capillary structure layer is connected to the third capillary structure layer or the liquid guiding groove on the outer surface of the support column to form a continuous reflux channel that connects the condensation end and the evaporation end, so as to shorten the reflux path of the cooling working fluid, enhance the capillary driving capability and improve the cycle stability.

[0022] The liquid guiding groove can be designed in different forms according to the working fluid reflux requirements and manufacturing process conditions, including vertical liquid guiding grooves distributed along the axis of the support column, spiral liquid guiding grooves extending spirally along the outer surface of the support column, etc.

[0023] The first, second, third, and fourth capillary layers can be composed of metal powder, metal wire, metal mesh, metal foam, or composite materials thereof. These capillary layers can be formed through processes such as sintering, electroplating, spraying, etching, laser cladding, or bonding to obtain the required porosity and capillary channel structure. Preferably, the capillary layer material can be a high thermal conductivity metal such as copper, aluminum, stainless steel, or nickel to balance thermal conductivity and capillary liquid absorption capacity. Alternatively, multi-layer stacking or gradient pore size designs can be adopted according to application requirements to enhance liquid wettability and capillary reflux capacity, while simultaneously promoting the uniform spreading and redistribution of the cooling medium on the condenser surface.

[0024] In addition, the first phase change cavity is evacuated before packaging and then filled with a certain amount of cooling medium. The filling rate of the medium can be determined according to the cavity volume and operating temperature range, and is preferably 30% to 70% of the total volume. When the chip is working, the heat it generates is conducted to the evaporation end in the phase change substrate, causing the cooling medium to vaporize and absorb heat in this area. The vaporized vapor flows upward in the first phase change cavity and condenses and releases heat on the surface of the condensation end. Subsequently, the condensed medium flows back to the evaporation end under the action of the capillary structure layer and / or the liquid guide groove and gravity, thereby forming a continuous vaporization-condensation cycle in the sealed cavity, realizing uniform heat diffusion and efficient heat transfer.

[0025] Furthermore, the cross-sectional shape of the support column is a straight cylinder, a tapered type, or a composite structure combining a straight cylinder section and a tapered section. The total height of the support column is B, and the height of the tapered section is b. The ratio of b to B ranges from 0 to 1. When b = 0, the support column is a straight cylinder structure; when b = B, the support column is a tapered structure; and when 0 < b < B, the support column is a composite structure.

[0026] When the support column is a tapering or composite structure, by forming a gradually contracting flow channel in the direction of the cooling medium's return flow, the cooling medium can be guided to accelerate its return flow to the evaporation end under the combined action of gravity and capillary force. At the same time, the flow resistance in the gas-liquid coexistence zone is reduced, and bubble retention is avoided, thereby improving the return flow rate of the cooling medium and the stability of the two-phase circulation.

[0027] Furthermore, a third recess is provided on the side of the jet plate facing the phase change base plate. The third recess includes a bottom surface and a side wall. The third recess is used to accommodate the second micro-rib structure and together with the enhanced heat exchange surface to form a second phase change cavity. The bottom surface of the recess constitutes the upper boundary surface of the second phase change cavity. The upper surface of the second micro-rib structure is in contact with or maintains a distance from the bottom surface of the recess.

[0028] When the upper surface of the second microrib structure is in contact with the bottom surface of the cavity or the distance between them is less than a set threshold (the distance is extremely small), the cooling medium forms a confined flow channel in the second phase change cavity and mainly exchanges heat in the form of flow boiling; when the upper surface of the second microrib structure and the bottom surface of the cavity maintain a certain distance, the cooling medium exchanges heat in the form of pool boiling in the second phase change cavity.

[0029] Furthermore, the jet plate has a first cavity and a second cavity on the side facing the top cover. A plurality of partition ribs are provided between the first cavity and the second cavity. The partition ribs are continuously arranged in an S-shape along the mainstream direction of the cooling medium to separate the inlet area and the outlet area of ​​the cooling medium. The first cavity is connected to the first interface, and the second cavity is connected to the second interface, so as to serve as the inlet and outlet of the cooling medium, respectively, to realize the circulation of the cooling medium in the second phase change cavity.

[0030] Furthermore, a jet structure is provided in the first concave cavity, which is a slit-type jet channel and / or jet hole. A reflux structure is provided in the second concave cavity, which is a slit-type reflux channel and / or reflux hole. The jet structure and reflux structure are arranged alternately and adjacently to form staggered jet and reflux zones. The cooling working fluid flows into the first concave cavity through the first interface and is then split. It is then sprayed into the second phase change cavity through the jet structure. In the second phase change cavity, a phase change and heat absorption occur. The vaporized working fluid is guided back to the second concave cavity by the adjacent reflux structure and collects. Finally, it is discharged through the second interface.

[0031] The first and second interfaces can also be connected to external condensation components to form a continuous flow-injection-vaporization-recirculation-condensation cycle.

[0032] Furthermore, the width of the return flow channel is preferably greater than the width of the jet flow channel, and the diameter of the return orifice is greater than the diameter of the jet orifice. Since the cooling medium expands in volume and decreases in density after vaporization in the second phase change cavity, setting the return flow channel and return orifice to a larger size will help reduce the flow resistance of the gas-liquid mixture, promote the smooth discharge of the vaporized medium and the timely return of the condensate, thereby improving the stability of the circulation process and the overall heat exchange efficiency.

[0033] Furthermore, the cross-sectional shape formed between the jet structure or return structure and two adjacent partition ribs is stepped or gradually changing. The stepped shape means that the minimum distance between adjacent partition ribs is greater than the maximum width of the jet channel or return channel, or greater than the maximum diameter of the jet hole or return hole, so that the channel forms a local step transition at the junction of adjacent areas, and its cross-sectional shape exhibits stepped characteristics. The term "gradual shape" refers to the minimum spacing between adjacent separating ribs being equal to the maximum width of the jet or return channel, or equal to the maximum diameter of the jet or return hole. In this case, the upper and lower contours of the channel transition continuously without obvious step differences.

[0034] By rationally designing and arranging the relative dimensional relationships between the jet channel, jet hole, return channel, and return hole, it is possible to achieve smoother flow of cooling medium in and out, thereby improving the heat transfer efficiency in the second phase change cavity, while meeting the requirements of machining accuracy, machining feasibility, and structural strength.

[0035] In practical applications, the phase change substrate and the chip can be tightly bonded through a thermally conductive interface material to reduce interfacial thermal resistance and ensure efficient heat conduction. The thermally conductive interface material can be thermally conductive grease, thermally conductive adhesive, phase change material, thermally conductive gel, metal solder, indium foil, thermally conductive pads, or composite thermally conductive sheets. For high heat flux density chips, indium foil, gold-tin solder, or silver-based solder are preferred as metal thermally conductive media to achieve higher thermal conductivity and more stable thermal contact performance. For structures requiring removable maintenance, thermally conductive grease, phase change material, or elastic thermally conductive pads can be used to reduce interfacial thermal resistance and ensure efficient heat conduction.

[0036] The phase change plate and the jet plate, as well as the jet plate and the top cover, can be connected by threads with a sealing ring, or fixed and sealed by welding, integral molding, or adhesive bonding, depending on structural requirements. In particular, for miniaturized or highly integrated applications, the phase change plate and the jet plate, and the jet plate and the top cover, can be machined or integrally molded to reduce the number of assembly interfaces, lower interface thermal resistance, and improve the overall sealing reliability.

[0037] The top cover and the core carrier plate can be fixedly connected by threads or adhesive for easy assembly and maintenance. Spot welding or brazing can also be used to assist in fixing when structural strength is required. When the top cover and the core carrier plate are connected by threads, the core carrier plate has threaded holes, and the top cover has through holes corresponding to the size, number, and distribution of the threaded holes. Screws are passed through the through holes in the top cover and screwed into the threaded holes in the carrier plate to achieve a reliable fastening connection between the top cover and the core carrier plate. The threaded holes in the carrier plate are either threaded through holes or threaded blind holes. The through holes in the top cover are preferably countersunk through holes without threads, so that the screw heads are flush with the outer surface of the top cover, avoiding assembly interference and improving the overall flatness.

[0038] The phase change plate can be made of metals or composite materials with high thermal conductivity to achieve rapid heat conduction and regional temperature diffusion. Preferably, its main material can be metals such as copper, aluminum, stainless steel, titanium, or nickel, or it can be a composite structure of metal and high thermal conductivity non-metals, such as copper-graphite, copper-silicon carbide, or copper-graphene composite materials. The above materials have excellent thermal conductivity and processing plasticity, and can quickly and evenly distribute the temperature under the action of working fluid vaporization-condensation cycle, thereby significantly improving the overall heat transfer performance and structural reliability of the phase change plate.

[0039] The jet plate and top cover can also be made of materials with good thermal conductivity, corrosion resistance, and structural strength, depending on the usage environment and structural requirements. Preferably, the material can be copper, aluminum, stainless steel, nickel, or their alloys to obtain high thermal conductivity and mechanical stability. For applications requiring insulation, corrosion resistance, or lightweighting, the jet plate and top cover can also be made of high thermal conductivity ceramic materials such as alumina, aluminum nitride, silicon nitride, and silicon carbide, or non-metallic materials such as high-performance resins, engineering plastics, and glass. If necessary, a metal-non-metal composite structure design can be used to balance thermal conductivity, strength, and sealing performance. In addition, the inner surfaces of the jet plate and top cover can be treated with nickel plating, anodizing, or anti-corrosion coating as needed to improve their corrosion resistance and long-term stability.

[0040] Furthermore, the cooling medium circulating in the second phase change cavity and the working medium injected into the phase change base plate can each be selected from various two-phase cooling media. The types do not need to be identical; they can be optimized based on factors such as operating temperature range, system pressure, material compatibility, and safety. The two-phase cooling media include water, alcohols, ammonia, light hydrocarbons, common refrigerants, mineral oil, transformer oil, fluorinated liquids, and molten salt solutions, etc.; alternatively, one of the above-mentioned working media or a composite coolant prepared from two or more components in a certain proportion can be used, such as water / ethylene glycol, water / propylene glycol mixtures, or water / alcohol mixtures.

[0041] Both the first and second interfaces can be connected to an external cooling system. The external cooling system may include a liquid storage unit, a circulating pump, a condenser heat exchanger, and a control module to regulate and monitor the temperature, flow rate, and velocity of the cooling medium, thereby dynamically adjusting the cooling capacity according to the chip's heat intensity or operating status and improving the overall thermal management performance of the system.

[0042] Compared with the prior art, the present invention has the following advantages: This invention designs a top cover, a jet plate, a phase change base plate, and a core carrier plate that are stacked and sealed together from top to bottom. A chip is mounted on the core carrier plate, and the bottom of the phase change base plate is in contact with the chip surface. The phase change base plate has a hollow interior containing a first phase change cavity, while a second phase change cavity is formed between the jet plate and the phase change base plate. The top cover has a first interface and a second interface for mounting connectors to allow the inflow and outflow of the cooling medium. This integrates cooling and heat diffusion functions, effectively reducing the overall thermal resistance between the chip and the heat dissipation interface. It achieves efficient phase change heat transfer of the cooling medium within the first and second phase change cavities. This device significantly improves the heat diffusion capacity and temperature uniformity of the heat-generating area, while also possessing excellent heat transfer efficiency and heat dissipation performance. It is compact, reliably sealed, and suitable for the efficient heat dissipation needs of various high heat flux density chips.

[0043] This invention constructs a phase change substrate structure with a hollow interior containing a first phase change cavity. The side of the first phase change cavity closest to the chip is the evaporation end, and the opposite side is the condensation end. Based on the synergistic effect of the evaporation and condensation ends, the vaporization and condensation cycle of the cooling medium during the phase change process achieves highly efficient heat conduction and diffusion performance. Furthermore, a support pillar is installed within the first phase change cavity, and a first microrib structure is provided on the evaporation end. The inner wall of the cavity, the surface of the support pillar, and the outer surface of the microrib structure are all covered with a capillary layer. The support pillar not only enhances the overall structural strength of the first phase change cavity, preventing deformation due to pressure fluctuations during the phase change cycle, but also shortens the return path of the cooling medium after condensation, reducing liquid flow resistance and improving the cooling medium circulation efficiency. The first microrib structure significantly enhances the local heat transfer and vaporization rate at the evaporation end, while the capillary layer facilitates the uniform spreading of the liquid film and rapid renewal of the gas-liquid interface, thereby effectively improving the evaporation and return rates and enhancing the heat diffusion capacity and temperature distribution uniformity within the cavity.

[0044] This invention designs a second microrib structure on the enhanced heat exchange surface and can cover its outer surface and the enhanced heat exchange surface with a second capillary structure layer to enhance the heat exchange performance of the condenser end within the phase change plate. Compared to the traditional separate design where the heat diffusion structure and cooling structure are independent, the phase change plate structure designed in this invention makes the heat transfer path more direct, simplifies the system assembly process, effectively reduces the contact thermal resistance caused by multi-layer assembly interfaces, improves overall sealing and operational reliability, and is conducive to long-term stable operation. Compared with traditional single-phase liquid cooling, phase change heat transfer can achieve higher heat exchange efficiency and faster heat diffusion.

[0045] This invention features a condensation groove at the condensation end. The inner surface of the condensation groove is hydrophobically treated, which promotes the rapid accumulation and detachment of condensate from the surface. Under the combined action of gravity and capillary force, the condensate quickly flows back to the evaporation area. Through the synergistic effect of the first and second micro-rib structures and the condensation groove, a stable and efficient evaporation-condensation cycle can be formed, significantly improving the two-phase heat transfer rate and overall heat diffusion speed inside the phase change substrate. This enables rapid heat diffusion and temperature field stability of the chip, meeting the high-efficiency heat dissipation requirements of high heat flux density chips.

[0046] This invention incorporates multiple jet and return structures on a jet plate, enabling the cooling medium to impact the surface of the heating area at a certain velocity and flow smoothly back. Simultaneously, separating ribs on the jet plate separate the jet and return cooling medium, improving the stability and uniformity of the cooling medium flow within the first and second concave cavities. Through a rational combination of jet and return structures, the cooling medium can circulate efficiently within the second phase change cavity. Furthermore, optimizing the relative dimensions of the jet and return structures, as well as the cross-sectional shapes of the jet, return, and adjacent separating ribs, further enhances heat dissipation efficiency.

[0047] In this invention, the first and second interfaces can be connected to an external cooling system to achieve loop circulation and controllable adjustment of the cooling medium. The external system can adaptively manage the thermal load under different chip power consumption or operating modes by adjusting the temperature, flow rate, and pressure of the coolant, further enhancing the overall system's intelligence level. Furthermore, the thickness, shape, and related parameters of the top cover can be designed and optimized according to chip size, packaging form, and installation space, further improving the device's adaptability and compactness, ensuring efficient heat dissipation and stable operation within a limited space. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the overall structure of Example 1; Figure 2 for Figure 1 A schematic diagram of the exploded structure; Figure 3 This is a schematic diagram of the core carrier plate in Example 1; Figure 4 This is a schematic diagram of the front (i.e., the side facing the jet plate) structure of the phase change base plate in Embodiment 1. Figure 5 This is a schematic diagram of the back side (i.e., the side where the chip is attached) of the phase change substrate in Example 1; Figure 6 This is a schematic diagram of the internal structure of the phase change base plate in Example 1; Figure 7 This is a schematic diagram of the sequential arrangement of the first microrib structure as a microrib column in Example 1; Figure 8 This is a schematic diagram of the insertion method when the first microrib structure in Example 1 is a discontinuously distributed microrib. Figure 9 This is a schematic diagram of the arrangement of microribs in Example 1 when the first microrib structure is a continuously distributed microrib. Figure 10 This is a schematic diagram of the second capillary layer covered by the second microrib structure in Example 1; Figure 11 This is a schematic diagram of the liquid guiding groove structure fabricated for the support column in Example 1; Figure 12 This is a schematic diagram of the cross-sectional shape of the support column in Example 1; Figure 13 This is a schematic diagram of the jet flow channel structure on the front side (i.e., the side facing the top cover) of the jet plate in Embodiment 1. Figure 14 This is a schematic diagram of the jet plate with jet holes on the front side (i.e., the side facing the top cover) in Embodiment 1. Figure 15 This is a schematic diagram of the back side (i.e., the side facing the phase change base plate) of the jet plate in Embodiment 1; Figure 16 This is a cross-sectional structural diagram of Example 1; Figure 17 This is a schematic diagram of the flow path of the cooling working fluid in the second phase change cavity in Example 1; Figure 18 This is a schematic diagram of the cross-sectional shape formed between the jet structure or recirculation structure and two adjacent partition ribs in Example 1. Figure 19 This is a schematic diagram of the front view (i.e., the side away from the jet plate) of the top cover in Embodiment 1; Figure 20 This is a schematic diagram of the structure of the back side (i.e., the side facing the jet plate) of the top cover in Embodiment 1; Figure 21 This is a cross-sectional structural diagram of Example 2; Explanation of markings in the diagram: 1. Core carrier board; 11. Chip; 12. Carrier board threaded hole. 2. Phase change base plate; 21. Evaporation end; 211. First micro-rib structure; 212. First capillary structure layer; 22. Enhanced heat exchange surface; 221. Second micro-rib structure; 222. Second capillary structure layer; 23. Support column; 231. Third capillary structure layer; 232. Liquid guide groove; 24. Fourth capillary structure layer; 25. First phase change cavity; 251. Condensation end; 252. Condensation groove; 26. Boss structure. 3. Jet plate; 31. First cavity; 311. Jet channel; 312. Jet hole; 32. Second cavity; 321. Return channel; 322. Return hole; 33. Separating rib; 34. Third cavity; 341. Bottom surface of cavity. 4. Top cover; 41. First interface; 42. Second interface; 43. Top cover through hole; 44. Top cover groove; 5. Connector; 6. Screws; h1, height of the first capillary layer; H1, total height of the first microrib structure; d1, thickness of the first capillary layer; D1, total thickness of the first microrib structure; h2, height of the second capillary layer; H2, total height of the second microrib structure; d2, thickness of the second capillary layer; D2, total thickness of the second microrib structure; B, total height of the support column; b, height of the tapering section of the support column; L, height of the boss structure. Detailed Implementation

[0049] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0050] Example 1 like Figure 1-2 As shown, this embodiment discloses a chip top-cover heat dissipation device based on a phase change heat transfer mechanism, including a core carrier plate 1, a phase change base plate 2, a jet plate 3, a top cover 4, and a connector 5. The top cover 4, jet plate 3, and phase change base plate 2 are stacked sequentially from top to bottom, and after being sealed and fixedly connected in pairs, they are then fastened to the core carrier plate 1 using screws 6. In this embodiment, the connector 5 uses a right-angle pagoda connector, which is installed and fixed on the top cover 4 to allow the inflow and outflow of the cooling medium. The side of the top cover 4 facing the core carrier plate 1 is used to accommodate the jet plate 3, the phase change base plate 2, and the chip 1; the top cover 4, jet plate 3, and phase change base plate 2 are stacked sequentially from top to bottom, and after being sealed and connected in pairs, they are installed on the core carrier plate 1.

[0051] like Figure 3 As shown, a chip 11 is mounted on the core carrier board 1, and multiple threaded holes 12 are provided around the chip 11 for engaging with screws 6 to achieve a secure connection of the entire device. In practical applications, one or more chips 11 can be mounted on the core carrier board 1.

[0052] like Figure 4-6As shown, a boss structure 26 is provided on the side of the phase change base plate 2 near the chip 11 to avoid electronic components around the chip 11 and prevent interference during the installation process; the height of the boss structure 26 is denoted as L, where L≥0. By reasonably adjusting the size of the boss structure 26 and the value of L, it can be ensured that the phase change base plate 2 and the chip 11 are fully in contact, thereby improving thermal contact stability and heat dissipation performance.

[0053] The phase change base plate 2 has a hollow cavity inside, namely the first phase change cavity 25. The side of the first phase change cavity 25 closest to the chip 11 is the evaporation end 21, and the opposite side of the evaporation end 21 is the condensation end 251. The evaporation end 21 is provided with a first micro-rib structure 211, and the outer surface of the evaporation end 21 and the first micro-rib structure 211 is covered with a first capillary structure layer 212 to enhance the wettability and capillary reflux capability of the liquid working fluid in the evaporation zone, thereby strengthening the heat transfer of the evaporation end 21. The side of the first phase change cavity 25 facing the jet plate 3 is a heat transfer enhancement surface 22, and the heat transfer enhancement surface 22 is provided with a second micro-rib structure 221. The outer surface of the heat transfer enhancement surface 22 and the second micro-rib structure 221 is covered with a second capillary structure layer 212 to enhance the heat transfer of the condensation end 251 in the first phase change cavity 25. The condensation end 251 is provided with a condensation groove 252, and the inner surface of the condensation groove 252 is hydrophobically treated to promote the separation and reflux of the working fluid.

[0054] The first phase change cavity 25 is provided with multiple support columns 23 to maintain the structural stability of the first phase change cavity 25. The outer surface of the support columns 23 is covered with a third capillary structure layer 231 to further expand the working fluid return channel and enhance the overall capillary driving force. The inner wall surface of the first phase change cavity 25 is covered with a fourth capillary structure layer 24. The inner surface of the condensation groove 252 is not provided with the fourth capillary structure layer 24 to maintain hydrophobic properties. The fourth capillary structure layer 24 is connected to the third capillary structure layer 231 to form a continuous capillary structure network, which helps to shorten the return path of the working fluid after condensation and improve the circulation efficiency.

[0055] like Figure 7-9 As shown, the first microrib structure 211 and the second microrib structure 221 are microrib pillars and / or microribs, and their arrangement includes linear arrangement and interleaved arrangement. Linear arrangement means that the first microrib structure 211 or the second microrib structure 221 are neatly arranged to form a regular array, which can reduce the flow resistance of the working fluid and maintain the stability of the flow direction; interleaved arrangement means that the adjacent rows of the first microrib structure 211 or the second microrib structure 221 are staggered or interleaved, which can enhance the disturbance and mixing effect of the working fluid and strengthen the heat transfer process of the cooling working fluid at the evaporation end and the condensation end.

[0056] like Figure 10As shown, the height of the second capillary layer 222 covering the enhanced heat exchange surface 22 is denoted as h2, and the total height of the second micro-rib structure 221 is denoted as H2; the thickness of the second capillary layer 222 covering the outer surface of the second micro-rib structure 221 is denoted as d2, and the total thickness of the second micro-rib structure 221 is denoted as D2; their proportional relationship satisfies 0 ≤ h2 / H2 ≤ 100%, 0 ≤ d2 / D2 ≤ 100%. Similarly, the height of the first capillary layer 212 covering the evaporation end 21 is denoted as h1, and the total height of the first micro-rib structure 211 is denoted as H1; the thickness of the first capillary layer 212 covering the outer surface of the first micro-rib structure 211 is denoted as d1, and the total thickness of the first micro-rib structure 211 is denoted as D1; ​​their proportional relationship is 0 < h1 / H1 ≤ 100%, 0 < d1 / D1 ≤ 100%. Wherein, h1 and d1 are both greater than zero, indicating that the surface of the evaporation end 21 is completely covered by the capillary layer. By adjusting the height and thickness of the capillary layer covering each surface, a dynamic balance between evaporation and condensation performance can be achieved under different heat flux densities, thus balancing efficient heat exchange with stable reflux.

[0057] like Figure 11-12 As shown, a liquid guiding groove 232 can be machined on the support column 23 to provide a low-resistance reflux channel for the condensed working fluid, thereby accelerating the liquid reflux speed. The groove width and depth can be designed according to the capillary force and working fluid viscosity to further improve the reflux smoothness. The cross-sectional shape of the support column 23 can be a straight cylinder, a tapering type, or a composite structure combining a straight cylinder section and a tapering section. The total height of the support column 23 is denoted as B, and the height of the tapering section is denoted as b. The ratio between the two is 0 ≤ b / B ≤ 1. When b = 0, the support column 23 is a straight cylinder structure with high mechanical support strength. When b = B, the support column 23 is a tapering structure with lower working fluid flow resistance, which is conducive to the rapid reflux and redistribution of the working fluid. When 0 < b < B, the support column 23 is a composite structure, which combines structural stability and fluid guidance, and can be optimized according to the working fluid circulation requirements inside the first phase change cavity 25.

[0058] like Figure 13-15As shown, the jet plate 3 is used to achieve the diversion, jetting, recirculation, and convergence of the working fluid. The side of the jet plate 3 facing the top cover 4 has a first cavity 31 and a second cavity 32, which serve as the inlet cavity and recirculation cavity for the cooling working fluid, respectively. The first cavity 31 and the second cavity 32 are separated by continuously arranged partition ribs 33 to limit the flow areas within them, preventing short circuits of the cooling working fluid and ensuring the orderliness of the jetting and recirculation processes. The first cavity 31 contains a jetting structure, which is a slit-type jet channel 311 and / or a jet hole 312. The second cavity 32 contains a recirculation structure, which is a slit-type recirculation channel 321 and / or a recirculation hole 322. The jetting and recirculation structures are arranged alternately and adjacently along the main flow direction of the cooling working fluid, forming staggered jetting and recirculation zones. This arrangement can enhance the multi-point impact and uniformly distributed flow field on the heat exchange surface 22, helping to strengthen local heat transfer and reduce the temperature gradient.

[0059] A third cavity 34 is provided on the side of the jet plate 3 facing the phase change base plate 2. This cavity accommodates the second micro-rib structure 221 and, together with the enhanced heat transfer surface 22, encloses and defines the second phase change cavity. The third cavity 34 includes a cavity bottom surface 341 and its circumferential sidewalls. The cavity bottom surface 231 defines the upper boundary surface of the second phase change cavity. The height of the second micro-rib structure 221 can be less than or equal to the depth of the third cavity 34. The dimensions of the jet structure and the reflux structure can be flexibly designed to ensure sufficient gas-liquid circulation space is formed without interfering with the flow of the working fluid. By adjusting the distance between the upper surface of the second micro-rib structure 221 and the cavity bottom surface 341, the working fluid can undergo phase change heat transfer in either pool boiling or flow boiling form.

[0060] like Figure 16-17 As shown, the arrows indicate the flow path of the cooling medium inside the device and in the second phase change cavity. After the cooling medium flows into the first concave cavity 31 and completes the flow distribution, it is sprayed into the second phase change cavity through the jet structure, where it fully contacts the enhanced heat exchange surface 22 and the second micro-rib structure 221 and undergoes phase change heat transfer. Then, it is guided by the reflux structure to the second concave cavity 32 for collection and discharge.

[0061] like Figure 18 As shown, the cross-sectional shape formed between the jet structure or recirculation structure and two adjacent partition ribs 33 is stepped or gradually changing. When it is stepped, the minimum distance between adjacent partition ribs 33 is greater than the maximum width of the jet channel 311 or recirculation channel 321, or greater than the maximum diameter of the jet hole 312 or recirculation hole 322; when it is gradually changing, the minimum distance between adjacent partition ribs 33 is equal to the maximum width of the jet channel 311 or recirculation channel 321, or equal to the maximum diameter of the jet hole 312 or recirculation hole 322.

[0062] like Figures 19-20As shown, the top cover 4 has a top cover groove 44 on the side facing the core carrier plate 1 to accommodate the jet plate 3, the phase change base plate 2, and the chip 11. The top cover groove 44 can limit the position of the internal components, prevent assembly misalignment, and improve the overall sealing performance. The jet plate 3 and the top cover 4, and the phase change base plate 2 and the jet plate 3 are sealed and fixedly connected by welding. The phase change base plate 2 and the chip 11 are tightly bonded by a thermally conductive interface material, thereby reducing the interface thermal resistance and ensuring efficient heat conduction. The top cover 4 is provided with a first interface 41, a first interface 42, and multiple top cover through holes 43. The first interface 41 and the second interface 42 are respectively used to install the connector 5. The first interface 41 is connected to the first cavity 31, and the second interface 42 is connected to the second cavity 32. One end of the first interface 41 is connected to the external cooling circuit liquid supply pipe, and the other end is connected to the return pipe, so as to realize the circulation of the working fluid in and out of the device. The top cover through hole 43 is preferably a countersunk through hole without threads. The top cover through hole 43 is coaxially arranged with the carrier plate threaded hole 12. Its number and size correspond to the carrier plate threaded hole 12, ensuring that the screw 6 can pass smoothly through the top cover through hole 43 and be screwed into the carrier plate threaded hole 12, so as to achieve a reliable fastening connection between the top cover 4 and the core carrier plate 1.

[0063] Example 2 like Figure 21 As shown, the main difference between this embodiment and Embodiment 1 is that the phase change base plate 2 is entirely embedded inside the third cavity 34 of the jet plate 3, with its outer edge tightly fitted to the inner wall of the third cavity 34, forming a more compact integrated structure. In this embodiment, the dimensions of the phase change base plate 2 match the dimensions of the third cavity 34, making the overall assembled structure simpler, which helps to reduce the weight and volume of the device and improve space utilization. While this embodiment offers superior structural compactness and thermal continuity due to the phase change base plate 2 being fully embedded in the third cavity 34, it requires higher positioning accuracy and sealing during assembly, and slightly reduces overall fixing strength and ease of later maintenance. Therefore, Embodiment 1 is more suitable for applications requiring highly reliable installation and replaceable heat dissipation modules, while Embodiment 2, in applications with limited volume and thickness, can achieve higher integration and is suitable for lightweight, compact heat dissipation systems.

[0064] In summary, this solution aims to address the problems in existing technologies, such as independent cooling and heat diffusion structures, high interfacial thermal resistance, long heat transfer paths, uneven temperature distribution, and low system integration. It proposes a chip top-cover heat dissipation device based on a phase change heat transfer mechanism. This device achieves rapid heat diffusion and two-phase coupled heat exchange in a compact structure, exhibiting low interfacial thermal resistance, high thermal response speed, and excellent temperature uniformity. It is well-suited to the high heat flux density heat dissipation requirements of high-performance computing, electronic devices, and optoelectronic packaging. It should be understood that the above-described embodiments are only for illustrating the technical solutions of this invention and are not intended to limit the scope of protection of this invention. Although the invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that various modifications and substitutions can be made to the structural form, size proportions, material selection, and process parameters of the above embodiments without departing from the spirit and essence of this invention. Such equivalent modifications or improvements should be considered to fall within the scope of protection of this invention.

Claims

1. A chip top-cover heat dissipation device based on a phase change heat transfer mechanism, characterized in that, The device includes a top cover (4), a jet plate (3), a phase change base plate (2), and a core carrier plate (1) stacked and sealed from top to bottom. A chip (11) is mounted on the core carrier plate (1). The bottom of the phase change base plate (2) is in contact with the surface of the chip (11). The phase change base plate (2) has a hollow interior with a first phase change cavity (25). A second phase change cavity is formed between the jet plate (3) and the phase change base plate (2). The top cover (4) has a top cover groove (44) for accommodating the jet plate (3), the phase change base plate (2), and the chip (11). The top cover (4) has a first interface (41) and a second interface (42) for installing a connector (5) to realize the inflow and outflow of the cooling working fluid.

2. The chip top cover heat dissipation device based on phase change heat transfer mechanism according to claim 1, characterized in that, The first phase change cavity (25) in the phase change base plate (2) is an evaporation end (21) on the side near the chip (11), and the opposite side of the evaporation end (21) is a condensation end (251). The side of the phase change base plate (2) facing the jet plate (3) is a heat exchange enhanced surface (22). The evaporation end (21) is provided with a first micro-rib structure (211) to enhance the phase change heat of the evaporation end (21), and the heat exchange enhanced surface (22) is provided with a second micro-rib structure (221) to improve the heat exchange efficiency of the condensation end (251).

3. The chip top cover heat dissipation device based on phase change heat transfer mechanism according to claim 2, characterized in that, The condensing end (251) is provided with a condensing groove (252), and the inner surface of the condensing groove (252) is hydrophobically treated to promote the separation and reflux of the cooling working fluid.

4. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 2, characterized in that, The evaporation end (21) is covered with a first capillary layer (212) of height h1, and the outer surface of the first microrib structure (211) is covered with a first capillary layer (212) of thickness d1. The total height of the first microrib structure (211) is H1, and the total thickness of the first microrib structure (211) is D1, where h1>0, d1>0, and 0 <h1 / H1≤100%,0<d1 / D1 ≤100%; The enhanced heat exchange surface (22) is covered with a second capillary layer (222) of height h2, and the outer surface of the second microrib structure (221) is covered with a second capillary layer (222) of thickness d2. The total height of the second microrib structure (221) is H2, and the total thickness of the second microrib structure (221) is D2; wherein h2≥0, d2≥0, and 0≤h2 / H2≤100%, 0≤d2 / D2≤100%.

5. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 1, characterized in that, The first phase change cavity (25) is provided with a plurality of support columns (23) to support the cavity structure of the first phase change cavity (25) and maintain its internal space stability. The outer surface of the support column (23) is covered with a third capillary structure layer (231) and / or a liquid guiding groove (232) to guide and promote the cooling working fluid to flow back down along the surface of the support column (23) to the evaporation end (21). The inner wall surface of the first phase change cavity (25) is covered with a fourth capillary structure layer (24). The inner surface of the condensation groove (252) is not provided with a fourth capillary structure layer (24) to maintain the hydrophobic properties of the area. The fourth capillary structure layer (24) is connected to the third capillary structure layer (231) or the liquid guide groove (232) on the outer surface of the support column (23) to form a continuous reflux channel that runs through the condensation end (251) and the evaporation end (21) to shorten the reflux path of the cooling working fluid, enhance the capillary driving capability and improve the cycle stability.

6. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 5, characterized in that, The cross-sectional shape of the support column (23) is a straight cylinder, a tapered type, or a composite structure combining a straight cylinder section and a tapered section. The total height of the support column (23) is B, and the height of the tapered section is b. The ratio of b to B is in the range of 0 to 1. When b = 0, the support column (23) is a straight cylinder structure; when b = B, the support column (23) is a tapered structure; when 0 < b < B, the support column (23) is a composite structure.

7. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 1, characterized in that, The jet plate (3) has a third cavity (34) on the side facing the phase change base plate (2). The third cavity (34) includes a cavity bottom surface (341) and its sidewalls. The third cavity (34) is used to accommodate the second micro-rib structure (221) and together with the enhanced heat exchange surface (22) to form a second phase change cavity. The cavity bottom surface (341) constitutes the upper boundary surface of the second phase change cavity. The upper surface of the second micro-rib structure (221) is in contact with or maintains a distance from the cavity bottom surface (341).

8. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 1, characterized in that, The jet plate (3) is provided with a first cavity (31) and a second cavity (32) on the side facing the top cover (4). A number of partition ribs (33) are provided between the first cavity (31) and the second cavity (32). The partition ribs (33) are continuously arranged in an S-shape along the mainstream direction of the cooling medium to separate the inlet area and the outlet area of ​​the cooling medium. The first cavity (31) is connected to the first interface (41), and the second cavity (32) is connected to the second interface (42) to serve as the inlet and outlet of the cooling medium, respectively, so as to realize the circulation of the cooling medium in the second phase change cavity.

9. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 8, characterized in that, The first cavity (31) is provided with a jet structure, which is a slit-type jet channel (311) and / or jet hole (312). The second cavity (32) is provided with a return structure, which is a slit-type return channel (321) and / or return hole (322). The jet structure and the return structure are arranged alternately and adjacently to form a staggered jet area and return area. The cooling working fluid flows into the first cavity (31) through the first interface (41) and then splits. It is sprayed into the second phase change cavity through the jet structure. In the second phase change cavity, a phase change and heat absorption occur. The vaporized working fluid is guided back to the second cavity (32) by the adjacent return structure and collects. Finally, it is discharged through the second interface (42).

10. A chip top cover heat dissipation device based on a phase change heat transfer mechanism according to claim 9, characterized in that, The cross-sectional shape formed between the jet structure or return structure and the two adjacent partition ribs (33) is stepped or gradually changing. The stepped shape means that the minimum distance between the adjacent partition ribs (33) is greater than the maximum width of the jet channel (311) or return channel (321), or greater than the maximum diameter of the jet hole (312) or return hole (322), so that the channel forms a local step transition at the junction of adjacent areas, and its cross-sectional shape exhibits step characteristics. The gradient shape refers to the minimum spacing between adjacent separating ribs (33) being equal to the maximum width of the jet channel (311) or the return channel (321), or equal to the maximum diameter of the jet hole (312) or the return hole (322). In this case, the upper and lower contours of the channel transition continuously without obvious step differences.

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