Capillary heat transfer structure of bag-shaped holes and micro-pillar composite array and its manufacturing method and application

Abstract

The present invention discloses a capillary heat transfer structure comprising a composite array of pocket holes and micropillars, as well as a manufacturing method and application. This structure belongs to the field of heat transfer technology. The structure comprises a substrate, a pocket hole array, and a curved side micropillar array. The pocket hole array comprises a plurality of orthogonally arranged pocket holes, each of which is a groove structure recessed downward from the substrate surface, with a narrow entrance and a large inner cavity. The curved side micropillar array comprises a plurality of orthogonally arranged curved side micropillars, each of which is a columnar structure protruding upward from the substrate surface, with a circular or multi-cusp star-shaped cross-section. The pocket holes and the curved side micropillars are arranged in an alternating pattern. This invention has the advantages of high nucleation efficiency and strong phase change capability.

Description

Technical Field

[0001] The present invention belongs to the field of heat transfer technology and relates to a heat dissipation structure, in particular to a capillary heat transfer structure of a bag-shaped hole and micro-column composite array, a manufacturing method and an application thereof. Background Art

[0002] With the rapid development of microelectronics technology, the emergence of highly integrated and high-energy-density products has brought about extremely high heat flux density. Traditional heat dissipation methods can no longer meet the heat dissipation needs of modern electronic equipment, which poses a great challenge to thermal management.

[0003] Capillary cooling utilizes a capillary structure to actively guide cooling liquid to the heat source and efficiently remove heat through evaporation. This technology is particularly applicable to the realization of ultra-thin heat dissipation components, helping to handle high heat flux density within a limited space, ensuring the temperature stability and reliable performance of the device. Therefore, capillary cooling technology has gradually become an indispensable means of thermal management in electronic equipment, providing an ideal solution for the heat dissipation of highly integrated electronic devices such as electronic equipment, aerospace, and laser systems in the trend of miniaturization. Its core technologies include heat pipe technology, phase change material cooling, micro-nanostructure design, etc. These background technologies work together to enable capillary cooling technology to effectively improve the heat dissipation efficiency in high-power density devices, enabling the equipment to operate stably.

[0004] Common capillary heat dissipation structures include microgrooves, metal meshes, and sintered powders. However, these methods are often accompanied by problems such as insufficient capillary force, insufficient liquid supply, and clogging. Especially in pool boiling, optimizing the capillary structure still has great potential to improve its nucleation efficiency and stability. Summary of the Invention

[0005] The present invention provides a capillary heat transfer structure of a composite array of bag-shaped holes and micro-pillars, a manufacturing method and an application thereof, so as to overcome the defects of the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a capillary heat transfer structure of a composite array of bag-shaped holes and micropillars: comprising a substrate, a bag-shaped hole array and a curved side micropillar array; the bag-shaped hole array is composed of a plurality of orthogonally arranged bag-shaped holes, the bag-shaped holes being groove structures recessed from the substrate surface into the substrate, the bag-shaped holes having a narrow entrance and a large inner cavity, and the "narrow" and "large" in the narrow entrance and large inner cavity are comparative relationships, that is, the entrance width is smaller than the inner cavity diameter; the curved side micropillar array is composed of a plurality of orthogonally arranged curved side micropillars, the curved side micropillars being columnar structures protruding upward from the substrate surface, the cross-section of the curved side micropillars being circular or multi-pointed and star-shaped; a plurality of bag-shaped holes and a plurality of curved side micropillars are staggered, that is, a plurality of bag-shaped holes are arranged in the gaps of the curved side micropillar array or a plurality of curved side micropillars are arranged in the gaps of the bag-shaped hole array.

[0008] Optionally, the pocket-shaped holes and the curved side micro-pillar surfaces have super-lyophilic micro-nano structures. Micro-nano structures refer to micron- and nanometer-scale structures.

[0009] Optionally, the substrate and the curved side micro-columns are made of metal materials such as copper, titanium, and nickel.

[0010] Optionally, the super-lyophilic micro-nanostructure is a nanowire, a villi or a porous structure produced on the surface of the bag-shaped holes and the curved side microcolumns by chemical etching and oxidation or laser ablation.

[0011] Optionally, the cross-section of the bag-shaped hole is in the shape of an arc.

[0012] Optionally, the bag-shaped holes have an entrance width of 0.4 to 1.6 mm, an inner cavity diameter of 0.5 to 2.5 mm, and an inner cavity depth of 0.5 to 2.0 mm; and in the bag-shaped hole array, a spacing between the bag-shaped holes is 0.5 to 5.0 mm.

[0013] Optionally, the envelope diameter of the curved side microcolumns is 0.5-2.0 mm, and the height is 1.0-5.0 mm; in the curved side microcolumns array, the pitch between the curved side microcolumns is 0.5-5.0 mm.

[0014] In a second aspect, the present invention provides a method for manufacturing the capillary heat transfer structure of the above-mentioned composite array of bag-shaped holes and micropillars, comprising the following steps: step 1, processing a bag-shaped hole array on a substrate; step 2, processing a curved side micropillar array staggered with the bag-shaped hole array on the substrate; step 3, processing a super-lyophilic micro-nanostructure on the surface of the bag-shaped holes and the curved side micropillars.

[0015] Optionally, in step one, an isotropic wet etching method is used to process a bag-shaped hole array; in step two, a curved side micro-pillar array is processed by mask electrodeposition; in step three, a super-lyophilic micro-nanostructure is processed by chemical etching and oxidation or laser ablation.

[0016] In a third aspect, the present invention provides an application of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars in heat dissipation.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention uses wet etching to construct pocket-shaped holes on the surface of a metal substrate. During the etching process, microscopic roughness is formed on the inner surface of the pocket-shaped holes and metal oxides are generated, which greatly enhances the liquid affinity of the pocket-shaped hole array structure and ensures the stability of the phase change liquid supply.

[0019] 2. The inner surface of the bag-shaped holes in the present invention has a super-lyophilic micro-nano structure, which can promote bubble nucleation. At the same time, the bag-shaped holes limit the lateral growth of bubbles and promote the longitudinal detachment of bubbles from the surface, forming a more stable and higher-frequency bubble nucleation, growth and detachment process.

[0020] 3. The structure of the present invention has a micro-column array with curved side edges, which can greatly increase the heat dissipation area and ensure sufficient supply of liquid along the columnar surface. It can also guide the upward path of bubbles, prevent the fusion of bubbles between boiling areas, accelerate their separation, and thus improve its boiling heat transfer limit.

[0021] Fourth, the micropillars with curved sides in the present invention have a star-shaped cross section. Due to their concave curvature, a stable liquid film is more easily formed on the surface of the micropillars with curved sides, thereby enhancing the phase change heat transfer limit.

[0022] 5. The pocket-shaped holes and the curved side micro-pillar surfaces of the present invention have a super-lyophilic micro-nanostructure, which promotes the spreading of liquid at the base of the micro-pillars, thereby greatly enhancing the capillary heat dissipation capability.

[0023] 6. The capillary heat dissipation structure proposed in the present invention can optimize and change the size of micro-columns and micro-pores according to the different liquid flow resistance, working pressure and heat dissipation pressure to cope with different working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 3D schematic diagram of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars of Example 1;

[0025] Figure 2 1 is a schematic top view of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars of Example 1;

[0026] Figure 3 2 is a cross-sectional schematic diagram of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars of Example 1;

[0027] Figure 4 3D schematic diagram of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars of Example 2;

[0028] Figure 5 2 is a schematic diagram of the cross-sectional structure of the curved side micropillars of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars of Example 2;

[0029] Figure 6 Schematic diagram of the cross-sectional structure of the curved side micropillars of the capillary heat transfer structure of the composite array of bag-shaped holes and micropillars in Example 3. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figures 1 to 3 As shown, this embodiment provides a capillary heat transfer structure of a composite array of bag-shaped holes and micro-pillars for heat dissipation, including a substrate 1, a bag-shaped hole array 2 and a curved side micro-pillar array 3.

[0033] The substrate 1 is made of copper and has a thickness of 1 mm.

[0034] The pocket hole array 2 is the lower layer of the composite structure and consists of a number of orthogonally arranged pocket holes 21. The pocket holes 21 have a square rim with a side length of 0.8 mm, an inner pocket diameter of 1 mm, a hole depth of 0.5 mm, and an arc-shaped cross-section. The pocket holes 21 are spaced 2 mm apart.

[0035] The curved side micropillar array 3 forms the upper layer of the composite structure and is composed of a number of orthogonally arranged curved side micropillars 31 made of copper. Each curved side micropillar 31 has a circular cross-section, a diameter of 1 mm, and a height of 5 mm. The spacing between each curved side micropillar is 2 mm.

[0036] A plurality of bag-shaped holes 21 and a plurality of curved side micro-pillars 31 are arranged alternately.

[0037] The surfaces of the bag-shaped holes 21 and the curved side micro-pillars 31 both have porous super-lyophilic micro-nano structures formed by chemical etching.

[0038] The manufacturing method of the capillary heat transfer structure comprises the following steps:

[0039] Step 1: Processing a pocket hole array 2 on a metal substrate 1 by isotropic wet etching;

[0040] Step 2: constructing curved side micro-pillars 31 on the metal substrate 1 by mask electrodeposition, and staggering them with the pocket hole array 2;

[0041] Step 3: Modify the surface of the structure by chemical etching to form super-lyophilic micro-nano structures densely distributed on the surface of the bag-shaped holes 21 and the curved side micro-pillars 31.

[0042] Example 2

[0043] like Figure 4 As shown, this embodiment provides a capillary heat transfer structure of a composite array of bag-shaped holes and micro-pillars for heat dissipation, including a substrate 1, a bag-shaped hole array 2 and a curved side micro-pillar array 3.

[0044] The substrate 1 is made of nickel and has a thickness of 0.5 mm.

[0045] The pocket hole array 2 is the lower layer of the composite structure and consists of a number of orthogonally arranged pocket holes 21. The pocket holes 21 have a square edge with a side length of 0.5mm, an inner pocket diameter of 0.5mm, a hole depth of 0.5mm, and an arc cross-section. The pocket holes 21 are spaced 1mm apart.

[0046] The curved side micro-pillar array 3 is the upper layer of the composite structure, and is composed of a number of curved side micro-pillars 31 arranged orthogonally, and the material is nickel. Figure 5 As shown, the cross section of the curved side micro-pillar 31 is a four-cusp star line, with an envelope diameter of 0.8 mm and a height of 2 mm. The pitch between the curved side micro-pillars 31 is 1 mm.

[0047] A plurality of bag-shaped holes 21 and a plurality of curved side micro-pillars 31 are arranged alternately.

[0048] The surfaces of the bag-shaped holes 21 and the curved side micro-pillars 31 both have porous super-lyophilic micro-nano structures formed by ultraviolet laser ablation.

[0049] The manufacturing method of the capillary heat transfer structure comprises the following steps:

[0050] Step 1: Processing a pocket hole array 2 on a metal substrate 1 by isotropic wet etching;

[0051] Step 2: constructing curved side micro-pillars 31 on the metal substrate 1 by mask electrodeposition, and staggering them with the pocket hole array 2;

[0052] Step 3: Use ultraviolet laser ablation to modify the surface of the structure, and process super-lyophilic micro-nano structures densely distributed on the surface of the bag-shaped holes 21 and the curved side micro-pillars 31.

[0053] Example 3

[0054] This embodiment provides a capillary heat transfer structure and manufacturing method of a composite array of bag-shaped holes and micropillars for heat dissipation, which is basically the same as that of Example 2, except that the cross section of the curved side micropillars 31 is a tricuspid line star line, such as Figure 6 shown.

[0055] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the reagents, materials and operating procedures used herein are those widely used in the corresponding fields.

[0056] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0057] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A capillary heat transfer structure of a composite array of bag-shaped holes and micropillars, characterized by: It includes a substrate, a pocket hole array, and a curved side micropillar array; The pocket hole array is composed of a number of pocket holes arranged orthogonally. The pocket holes are groove structures that are sunken downward from the substrate surface. The pocket holes have narrow entrances and large inner cavities. The curved side micro-pillar array is composed of a plurality of curved side micro-pillars arranged orthogonally. The curved side micro-pillars are columnar structures protruding upward from the substrate surface. The cross section of the curved side micro-pillars is circular or multi-pointed star-shaped. Several pocket-shaped holes and several curved side micro-pillars are arranged alternately; The bag-shaped holes and the curved side micro-column surfaces have super-liquid-philic micro-nano structures.

2. The capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to claim 1, characterized in that: The substrate and the micro-pillars on the curved side are both made of metal.

3. The capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to claim 2, characterized in that: The super-lyophilic micro-nano structure is a nanowire, a villi or a porous structure produced on the surface of bag-shaped holes and curved side microcolumns by chemical etching, oxidation or laser ablation.

4. The capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to claim 1, characterized in that: The cross section of the bag-shaped hole is in the shape of an arc.

5. The capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to claim 1, characterized in that: The bag-shaped hole has an entrance width of 0.4-1.6 mm, an inner cavity diameter of 0.5-2.5 mm, and an inner cavity depth of 0.5-2.0 mm; In the pocket hole array, the spacing between the pocket holes is 0.5~5.0 mm.

6. The capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to claim 1, characterized in that: The envelope diameter of the curved side microcolumns is 0.5-2.0 mm, and the height is 1.0-5.0 mm; In the curved side micropillar array, the pitch of the curved side micropillars is 0.5~5.0 mm.

7. The method for manufacturing a capillary heat transfer structure of a composite array of bag-shaped holes and micropillars according to any one of claims 1 to 6, wherein: The steps include: Step 1: Processing a pocket hole array on a substrate; Step 2: Processing a curved side micro-pillar array on the substrate that is interlaced with the pocket hole array; Step 3: Processing super-lyophilic micro-nano structures on the surface of bag-shaped holes and curved side micro-pillars.

8. The method for manufacturing a capillary heat transfer structure of a composite array of bag-shaped holes and micropillars according to claim 7, wherein: In step 1, an isotropic wet etching process is used to process the pocket hole array; In step 2, a curved side micropillar array is fabricated by mask electrodeposition; In step three, chemical etching and oxidation or laser ablation are used to process the super-lyophilic micro-nanostructure.

9. Application of the capillary heat transfer structure of the bag-shaped hole and micro-pillar composite array according to any one of claims 1 to 6 in heat dissipation.

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