An inverse opal copper capillary wick structure and manufacturing method thereof

Abstract

This invention relates to an inverse opal copper capillary wick structure and its manufacturing method. The manufacturing method includes the following steps: uniformly distributing multiple microspheres on a copper substrate; forming sintered necks between the microspheres through a sintering process; arranging nanoscale copper particles in the gaps between the microspheres to form a stable copper structure; removing the microspheres and sintered necks from the copper substrate; and forming multiple spherical cavities and sintered neck cavities within the copper structure. These spherical cavities and sintered neck cavities are respectively matched to the microspheres and sintered necks, and are interconnected through the sintered neck cavities. First, multiple microspheres are uniformly distributed on a copper substrate. Nanoscale copper particles are arranged in the gaps between the microspheres to form a stable copper structure. After removing the microspheres and sintered necks, multiple spherical cavities and sintered neck cavities are formed within the copper structure. The capillary action of the inverse opal copper capillary wick structure is further optimized through the synergistic effect of permeability and capillary force.

Description

Technical Field

[0001] This invention belongs to the field of heat pipe capillary wick technology, specifically relating to an inverse opal copper capillary wick structure and its manufacturing method. Background Technology

[0002] With the miniaturization and high integration of electronic devices, the power of electronic devices, especially chips, is constantly increasing, and the resulting heat generation problem is becoming increasingly serious. As electronic devices become increasingly compact, heat dissipation becomes more and more urgent. Phase change heat transfer technology is an excellent choice for solving high heat flux density problems in such confined spaces. Phase change heat transfer technology utilizes the latent heat of liquid-vapor phase change in a vacuum chamber to carry heat, transferring it away through gas-liquid circulation. The capillary wick is the core structure for realizing this gas-liquid circulation, playing a role in liquid reflux while also providing more vaporization nuclei for enhanced boiling, achieving highly efficient latent heat exchange.

[0003] Common capillary wicks include copper wire mesh, sintered copper powder, and microgroove structures.

[0004] Taking sintered copper powder, which has a relatively flexible structure in existing technologies, as an example, the pores of sintered copper powder provide a good channel for the transport of the working fluid, but it has the following technical problems:

[0005] Its porosity is typically only 50% to 60%, resulting in relatively low permeability and significant permeation resistance. However, the relatively small pore size can further enhance the capillary force of the structure, playing a positive role in the transport of the working fluid within.

[0006] Only the synergistic effect of permeability and capillary force can better reflect the capillary performance of a structure. Therefore, how to balance the magnitude of permeability and capillary force is the key to further optimizing the performance of various capillary structures. Summary of the Invention

[0007] In view of the technical problems existing in the prior art, one of the objectives of the present invention is to provide a method for manufacturing an inverse opal copper capillary wick structure, which can prepare a capillary wick structure with both high capillary force and high permeability, and has excellent performance in enhancing boiling and phase change heat transfer.

[0008] In view of the technical problems existing in the prior art, the second objective of the present invention is to provide an inverse opal copper capillary wick structure.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A method for manufacturing an inverse opal copper capillary wick structure includes the following steps: uniformly distributing multiple microspheres on a copper substrate; forming sintering necks between the microspheres through a sintering process; arranging nanoscale copper particles in the gaps between the multiple microspheres and forming a stable copper structure with the nanoscale copper particles; removing the multiple microspheres and sintering necks from the copper substrate; forming multiple spherical cavities and sintering neck cavities in the copper structure; the spherical cavities and sintering neck cavities are respectively matched with the microspheres and sintering necks; and the spherical cavities are connected to each other through the sintering neck cavities.

[0011] Furthermore, the method of uniformly distributing multiple microspheres on a copper substrate is to use an airbrush to spray uniformly distributed polymer polystyrene microspheres onto the copper substrate.

[0012] Furthermore, the method to uniformly distribute multiple microspheres on a copper substrate is to prepare polystyrene microspheres into a slurry and then use substrate dispensing to uniformly distribute the microspheres on the copper substrate.

[0013] Furthermore, the method to arrange nanoscale copper particles in the gaps between multiple microspheres and to make the nanoscale copper particles form a stable copper structure is as follows: nanoscale copper particles are grown in the gaps between the microspheres by electrodeposition technology, and the nanoscale copper particles are sintered at high temperature to form a stable copper structure.

[0014] Furthermore, the removal of multiple microspheres and sintering necks on the copper substrate is achieved by removing the polymeric polystyrene microspheres and sintering necks at high temperature, leaving spherical cavities and sintering neck cavities in the copper structure.

[0015] Furthermore, it includes the following steps:

[0016] Step A, cleaning the copper substrate: Immerse the copper substrate in 0.1 mol / L hydrochloric acid, ultrasonically clean for 3 minutes, remove the substrate, clean with deionized water, immerse in anhydrous ethanol, ultrasonically clean for 3 minutes, remove and clean with deionized water, and wipe clean with lint-free paper.

[0017] Step B, prepare polystyrene polymer suspension: Weigh 0.2g of polystyrene microspheres, measure out 5ml of anhydrous ethanol using a graduated cylinder, pour the polystyrene microspheres into the anhydrous ethanol, and stir evenly to form a suspension;

[0018] Step C, Microsphere Assembly: Using a spray gun, adjust the liquid flow rate to 0.08ml / s to 0.1ml / s and the gas-liquid ratio to 3:1, and uniformly spray the polystyrene suspension onto the surface of the copper substrate, leaving a 10mm gap.

[0019] Step D: Bake in an oven at a set temperature of 120°C for 180 minutes;

[0020] Step E, prepare the copper deposition solution: take 160-240g of copper sulfate pentahydrate and 60-80g of sulfuric acid, mix them to form an acidic copper sulfate solution, and then add two drops of hydrochloric acid.

[0021] Step F, electrodeposition: Take a DC current of 0.1 to 0.15 A, connect the remaining 10 mm of the sample plate to the cathode of the power supply, immerse the remaining part in the deposition solution, connect the anode to a pure copper electrode, and deposit for 3 hours;

[0022] Step G, template removal: Place the sample in a 500℃ vacuum oven and bake for 1.5 hours. Remove the sample to obtain an inverse opal copper wick.

[0023] An inverse opal copper capillary wick structure is prepared by a manufacturing method for an inverse opal copper capillary wick structure, comprising a copper substrate, on which multiple spherical cavities and sintered neck cavities are uniformly and densely distributed, the spherical cavities are connected through the sintered neck cavities, and nanoscale copper particles are arranged in the gaps between the spherical cavities to form a stable copper structure.

[0024] Furthermore, the copper substrate has a length of 105–110 mm, a width of 9–11 mm, and a thickness of 0.5–0.8 mm.

[0025] Furthermore, the spherical cavity has a size of 5 μm.

[0026] Furthermore, the capillary absorbent core has a length of 95–100 mm, a width of 9–10.5 mm, and a thickness of 30–50 μm.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention interchanges the space between copper powder and pore space in conventional sintered copper powder. First, multiple microspheres are uniformly and densely distributed on a copper substrate. Adjacent microspheres are connected by sintered necks. Nanoscale copper particles are arranged in the gaps between the microspheres, forming a stable copper structure. Then, the microspheres and sintered necks on the copper substrate are removed. After removal, multiple spherical cavities and sintered neck cavities, respectively matching the microspheres and sintered necks, are formed in the copper structure. These spherical cavities are interconnected through the sintered neck cavities, thus preparing an inverse opal copper capillary wick structure. This structure possesses both the high capillary force generated by the nano-copper particles and the high permeability generated by the microsphere cavities, exhibiting excellent performance in enhancing boiling and phase change heat transfer, making it a preferred solution for capillary wick structures in heat pipes. The capillary performance of the inverse opal copper capillary wick structure is further optimized through the synergistic effect of permeability and capillary force. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the inverse opal copper capillary wick structure of the present invention.

[0030] In the picture:

[0031] 1-Copper substrate, 2-Microspheres, 3-Copper particles, 4-Spherical cavity, 5-Sintered neck cavity. Detailed Implementation

[0032] Currently common capillary wicks include copper wire mesh, sintered copper powder, and microgroove structures. Taking sintered copper powder, with its relatively flexible structure, as an example, the pores of sintered copper powder provide good channels for the transport of the working fluid, but its porosity is only 50%–60%, resulting in relatively low permeability and significant permeation resistance. However, the relatively small pore size can further enhance the capillary force of the structure, playing a positive role in the internal transport of the working fluid. Therefore, the synergistic effect of permeability and capillary force is necessary to demonstrate the capillary performance of the structure, and how to balance the magnitude of permeability and capillary force is the key to further optimizing the performance of various capillary structures. Therefore, it is considered to interchange the copper powder space and pore space to prepare an inverse opal copper structure. By continuously expanding the sintering channels of the inverse opal copper, the permeability of the structure can be significantly increased without excessively damaging the capillary force, thereby improving capillary performance. However, the current common methods for preparing inverse opal copper wicks are too cumbersome, especially the self-assembly process of microspheres, which requires a lot of time or extremely complex equipment and processes, making the industrialization of this capillary structure difficult.

[0033] Therefore, this invention provides a simple and direct method for preparing an inverse opal copper wick structure. The assembly of microspheres 2 is achieved through a spraying process, which not only realizes the good capillary force and permeability of the inverse opal structure, but also greatly improves the manufacturing efficiency of the structure.

[0034] The present invention will now be described in further detail.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides a capillary wick structure based on inverse opal copper, including a copper substrate 1. The copper substrate 1 has a plurality of spherical cavities 4 and sintered neck cavities 5 uniformly distributed on it. The spherical cavities 4 are connected to each other through the sintered neck cavities 5. Nanoscale copper particles 3 are arranged in the gaps between the spherical cavities 4 to form a stable copper structure.

[0037] Specifically, a uniformly dense array of polymeric polystyrene microspheres 2 is sprayed onto a copper substrate 1 using an airbrush, or the polymeric polystyrene microspheres 2 are prepared into a slurry and then evenly distributed on the copper substrate 1 using substrate dispensing. A sintering process is used to form sintering necks between the microspheres 2. Nanoscale copper particles 3 are grown in the gaps between the microspheres 2 using electrodeposition technology. Then, the nanoscale copper particles 3 are sintered at high temperature to form a stable copper structure. At the same time, the polymeric polystyrene microspheres 2 and sintering necks are removed at high temperature, leaving spherical cavities 4 and sintering neck cavities 5 in the copper structure. The spherical cavities 4 are connected through the sintering neck cavities 5.

[0038] In this embodiment, the copper substrate has a length of 105–110 mm, a width of 9–11 mm, and a thickness of 0.5–0.8 mm. Polystyrene microspheres with a size of 5 μm are selected. The resulting capillary wick has a length of 95–100 mm, a width of 9–10.5 mm, and a thickness of 30–50 μm.

[0039] The manufacturing steps of the inverse opal copper capillary wick are as follows:

[0040] Step A: Immerse copper substrate 1 in 0.1 mol / L hydrochloric acid, ultrasonically clean for 3 minutes, remove the substrate, clean with deionized water, immerse in anhydrous ethanol, ultrasonically clean for 3 minutes, remove and clean with deionized water, and wipe clean with lint-free paper.

[0041] Step B: Prepare a polystyrene polymer suspension. Weigh 0.2g of polystyrene microspheres 2, measure 5ml of anhydrous ethanol using a graduated cylinder, pour the polystyrene microspheres 2 into the anhydrous ethanol, and stir until a suspension is formed.

[0042] Step C: Using an airbrush, adjust the liquid flow rate to 0.08ml / s to 0.1ml / s and the gas-liquid ratio to 3:1, and uniformly spray the polystyrene suspension onto the surface of the copper substrate 1, leaving a 10mm gap.

[0043] Step D: Bake in an oven at a set temperature of 120°C for 180 minutes.

[0044] Step E: Prepare the copper deposition solution by taking 160-240g of copper sulfate pentahydrate and 60-80g of sulfuric acid, mixing them to form an acidic copper sulfate solution, and then adding two drops of hydrochloric acid.

[0045] Step F: Take a DC current of 0.1 to 0.15 A, connect the remaining 10 mm portion of the sample plate to the cathode of the power supply, immerse the remaining portion in the deposition solution, connect the anode to a pure copper electrode, and deposit for 3 hours.

[0046] Step G: Place the sample in a vacuum oven at 500℃ and bake for 1.5 hours. Remove the sample to obtain an inverse opal copper wick.

[0047] Example 2

[0048] The difference between this embodiment and Embodiment 1 is that the microsphere 2 assembly process in step C can also use the polystyrene microsphere 2 suspension as a slurry to be poured into a dispensing container, and the polystyrene microsphere 2 can be uniformly sprayed onto the substrate using a dispensing machine.

[0049] The advantages of this invention compared to the prior art are as follows:

[0050] 1. This invention employs an inverse opal copper wick structure, which improves the permeability of the wick while ensuring capillary force, thereby significantly improving capillary performance.

[0051] 2. The present invention uses a spraying process or a dispensing printing method to assemble microspheres 2, which greatly improves the speed and feasibility of microsphere 2 assembly and reduces material consumption and manufacturing costs.

[0052] 3. The role of this invention in industrial applications is to promote the application of inverse opal copper structures as capillary structures in the field of ultrathin heat sinks, providing a better solution for heat dissipation of highly integrated electronic products such as chips.

[0053] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing an inverse opal copper capillary wick structure, characterized in that: The process includes the following steps: uniformly distributing multiple microspheres on a copper substrate; forming sintering necks between the microspheres through a sintering process; arranging nanoscale copper particles in the gaps between the multiple microspheres and forming a stable copper structure with the nanoscale copper particles; removing the multiple microspheres and sintering necks from the copper substrate; forming multiple spherical cavities and sintering neck cavities in the copper structure; matching the spherical cavities and sintering neck cavities with the microspheres and sintering necks respectively; and connecting the spherical cavities through the sintering neck cavities. The method to achieve uniformly densely distributed microspheres on a copper substrate is to spray uniformly densely distributed high-molecular polystyrene microspheres onto the copper substrate using an airbrush; or, to prepare polystyrene microspheres into a slurry and use substrate dispensing to uniformly distribute the microspheres onto the copper substrate. The method to arrange nanoscale copper particles in the gaps between multiple microspheres and make the nanoscale copper particles form a stable copper structure is to grow nanoscale copper particles in the gaps between microspheres by electrodeposition technology, and to form a stable copper structure by high-temperature sintering of the nanoscale copper particles. The method to remove multiple microspheres and sintered necks on the copper substrate is to remove the polymer polystyrene microspheres and sintered necks at high temperature, leaving spherical cavities and sintered neck cavities in the copper structure.

2. A method for manufacturing an inverse opal copper capillary wick structure according to claim 1, characterized in that: Includes the following steps, Step A, cleaning the copper substrate: Immerse the copper substrate in 0.1 mol / L hydrochloric acid, ultrasonically clean for 3 minutes, remove the substrate, clean with deionized water, immerse in anhydrous ethanol, ultrasonically clean for 3 minutes, remove and clean with deionized water, and wipe clean with lint-free paper. Step B, prepare polystyrene polymer suspension: Weigh 0.2g of polystyrene microspheres, measure out 5ml of anhydrous ethanol using a graduated cylinder, pour the polystyrene microspheres into the anhydrous ethanol, and stir evenly to form a suspension; Step C, Microsphere Assembly: Using a spray gun, adjust the liquid flow rate to 0.08ml / s to 0.1ml / s and the gas-liquid ratio to 3:1, and uniformly spray the polystyrene suspension onto the surface of the copper substrate, leaving a 10mm gap. Step D: Bake in an oven at a set temperature of 120°C for 180 minutes; Step E, prepare the copper deposition solution: take 160-240g of copper sulfate pentahydrate and 60-80g of sulfuric acid, mix them to form an acidic copper sulfate solution, and then add two drops of hydrochloric acid. Step F, electrodeposition: Take a DC current of 0.1 to 0.15 A, connect the remaining 10 mm of the sample plate to the cathode of the power supply, immerse the remaining part in the deposition solution, connect the anode to a pure copper electrode, and deposit for 3 hours; Step G, template removal: Place the sample in a 500℃ vacuum oven and bake for 1.5 hours. Remove the sample to obtain an inverse opal copper wick.

3. A reverse opal copper capillary wick structure, characterized in that: The method for manufacturing an inverse opal copper capillary wick structure according to claim 1 or 2 includes a copper substrate, on which multiple spherical cavities and sintered neck cavities are uniformly and densely distributed, the spherical cavities are connected through the sintered neck cavities, and nanoscale copper particles are arranged in the gaps between the spherical cavities to form a stable copper structure. The copper substrate has a length of 105–110 mm, a width of 9–11 mm, and a thickness of 0.5–0.8 mm. The spherical cavity has a size of 5 μm.

4. The inverse opal copper capillary wick structure according to claim 3, characterized in that: The capillary absorbent core has a length of 95–100 mm, a width of 9–10.5 mm, and a thickness of 30–50 μm.

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