阅读说明：本技术 一种基于液态金属浸润的内封装自适应型均温热界面及其制备方法和应用 (Inner-packaging self-adaptive uniform-temperature thermal interface based on liquid metal infiltration and preparation method and application thereof ) 是由 江雷 白春礼 田野 徐哲 余臻伟 于 2021-07-07 设计创作，主要内容包括：本发明公开一种基于液态金属浸润的内封装自适应型均温热界面,包括散热部件主体表面和形成于散热部件主体表面的微纳米复合结构；所述微纳米复合结构包括微米乳突阵列和液态金属,其中液态金属封装在微米乳突阵列间隙。该热界面是与散热部件一体化的,能够大幅降低热阻、实现快速均温,热界面可获得接近散热部件主体材质的超高导热效率。同时,该热界面成本低廉、拆装方便、性能稳定、防漏效果好、可应用于任意场景,匹配不同的散热部件,具有良好的应用前景。(The invention discloses an inner packaging self-adaptive temperature-equalizing thermal interface based on liquid metal infiltration, which comprises a main body surface of a heat dissipation component and a micro-nano composite structure formed on the main body surface of the heat dissipation component; the micro-nano composite structure comprises a micrometer mastoid array and liquid metal, wherein the liquid metal is packaged in the gap of the micrometer mastoid array. The thermal interface is integrated with the heat dissipation component, so that the thermal resistance can be greatly reduced, the rapid temperature equalization can be realized, and the thermal interface can obtain the ultrahigh heat conduction efficiency close to the material quality of the heat dissipation component body. Meanwhile, the thermal interface is low in cost, convenient to disassemble and assemble, stable in performance, good in leakage-proof effect, capable of being applied to any scene, matched with different heat dissipation components and good in application prospect.)

1. An inner packaging self-adaptive temperature-equalizing thermal interface based on liquid metal infiltration is characterized by comprising a heat dissipation component main body surface and a micro-nano composite structure formed on the heat dissipation component main body surface; the micro-nano composite structure comprises a micrometer mastoid array and liquid metal, wherein the liquid metal is packaged in the gap of the micrometer mastoid array.

2. The liquid metal infiltration-based inner-packaging adaptive uniform-temperature thermal interface according to claim 1, wherein the height of the micrometer mastoid is 5 μm to 500 μm, the equivalent diameter is 10 μm to 1000 μm, and the distance between adjacent micrometer mastoids is 10 μm to 1000 μm;

preferably, the micro-papillary surface has a particulate, clustered, fibrous, or convoluted nanotopography;

preferably, the diameter of the particulate or clustered nanotopography is 5nm to 500nm, the length of the fibrous nanotopography is 5nm to 500nm, and the thickness of the corrugated nanotopography is 5nm to 500 nm.

3. The liquid metal infiltration-based inside-package adaptive uniform temperature thermal interface of claim 1, wherein the melting point of the liquid metal is higher than room temperature but lower than the stable operating temperature of the heat generating device.

4. The liquid metal infiltration-based inner package adaptive uniform temperature thermal interface according to claim 1, wherein the liquid metal is selected from gallium, indium, tin, bismuth or alloys thereof, or doped mixtures thereof with other metals, oxides of other metals, non-metals or non-metal oxides; the other metal is selected from copper, aluminum, gold, silver, tungsten, rhodium or iridium, and the nonmetal is carbon or silicon.

5. The liquid metal infiltration-based inside-package adaptive uniform temperature thermal interface of claim 1, wherein the interstices of the micro-mastoid array are entirely filled with liquid metal.

6. The liquid metal infiltration-based inner packaging adaptive uniform temperature thermal interface of claim 1, wherein the surface of the micro mastoid array has a static contact angle of less than 10 ° to liquid metal droplets in an air or oxygen-free environment.

7. A preparation method of an inner packaging adaptive uniform-temperature thermal interface based on liquid metal infiltration according to any one of claims 1 to 6, characterized by comprising the following steps: the surface of the main body of the heat dissipation part is etched to form a micrometer mastoid array, the infiltration property of the micrometer mastoid array is regulated and controlled, and the liquid metal is packaged.

8. The preparation method of claim 7, wherein the etching method for etching the surface of the body of the heat dissipation component to form the micrometer mastoid array comprises electrochemical etching, chemical etching, 3D printing, plasma etching, photolithography or laser integrated etching; preferably, the method for regulating the infiltration property of the micrometer mastoid array comprises chemical reagent modification, functional medium deposition, plasma treatment, ozone treatment or ultraviolet irradiation.

9. The method of manufacturing of claim 7, wherein the liquid metal encapsulation comprises the steps of: preheating the micrometer mastoid array, infiltrating and filling the molten liquid metal into the gap of the micrometer mastoid array, and then cooling and solidifying to finish the packaging of the liquid metal.

10. The use of the liquid metal infiltration-based inner-package adaptive temperature-equalizing thermal interface as claimed in any one of claims 1 to 6 in the fields of electronic information, aerospace thermal control, and advanced energy.

Technical Field

The invention relates to the technical field of heat conduction equipment. And more particularly, to an inner package adaptive uniform temperature thermal interface based on liquid metal infiltration.

Background

With the progress and development of the microelectronic information industry, the 5G era has arrived silently, the chip tends to be packaged in a high integration, large density and miniaturization mode, the heating density is increased sharply, and the heat dissipation technology becomes a key bottleneck restricting the field development. If the problem of poor heat conduction of electronic devices is solved, the performance stability is directly influenced, the processing speed is reduced, the power dissipation is increased, and the service life is shortened.

In practical applications, a small-sized heating device often needs to be attached to a heat dissipation component (such as a fin, a heat sink, a heat pipe, a cold plate, a vapor chamber, etc.) with a larger area and higher heat exchange efficiency to enhance heat transfer. However, due to the differences in flatness and roughness of the respective surfaces, which are often difficult to match perfectly, micro-scale air (thermal conductivity of only about 0.024W m) at the gap therebetween^-1K^-1) It causes a very large contact resistance and seriously retards the heat transfer.

A Thermal Interface (TIM for short) is a general name of a Material applied between a heating device and a heat dissipation device to reduce Thermal contact resistance (as an intermediate layer to replace air in a gap of the contact Interface), and mainly includes heat conductive silicone grease, a heat conductive pad, heat conductive glue, heat conductive paste, a phase change Material, a graphite sheet, and the like. Although the thermal conductivity (generally reported thermal conductivity range is about 0.5-40W m)^-1K^-1) Greatly increased compared with air, but far short of reaching the heat dissipation part (usually, copper, aluminum, etc., copper has a thermal conductivity of about 400W m^-1K^-1Aluminum thermal conductivity about 235W m^-1K^-1) Magnitude. Even the most advanced liquid metal thermal interface (application publication No. CN 101338181A, CN 106222490A, CN 106929733A, CN 107052308A, CN 110330943A) has thermal conductivity not exceeding 100W m after complex preparation or regulation procedures of mixing, doping, modifying, sintering, smelting, infiltration casting, cold rolling and the like^-1K^-1. Thus, the TIM is still a heat transfer resistance for the entire heat dissipation system.

Meanwhile, the existing liquid metal thermal interface is an 'external' package, is independent of a heating device and a radiating part, and brings extra cost burden, assembly difficulty and operation and maintenance risks to the whole system, for example: the method needs to add a large amount of additives to improve the dispersion, flow or heat conduction performance of the liquid metal (application publication No. CN 107350663A, CN 108192576A, CN 108129841A, CN 110330943A), needs to strictly control the coating process to ensure that the contact interface is uniformly attached (application publication No. CN 111945159A), needs to prevent the short circuit accident caused by the side leakage of the molten components (application publication No. CN 106884107A, CN 106957980A, CN 107053786A, CN 107513377A) and the like.

Accordingly, it is desirable to provide a thermal interface that avoids the cost burden, assembly difficulties, and operational risks associated with "external" packaging, and that has high thermal conductivity.

Disclosure of Invention

One object of the present invention is to provide an inner-packaging adaptive uniform temperature thermal interface based on liquid metal infiltration, in which the liquid metal is directly packaged to the surface of the main body of a heat dissipation component, and when the liquid metal is heated and melted, the liquid metal can automatically fill contact gaps and tightly adhere to a heating device, so as to realize rapid uniform temperature and obtain ultrahigh heat conduction efficiency close to the material of the main body of the heat dissipation component.

The invention also aims to provide a preparation method of the inner packaging self-adaptive uniform-temperature thermal interface based on liquid metal infiltration.

It is yet another object of the present invention to provide an application of an inner package adaptive uniform temperature thermal interface based on liquid metal infiltration.

The thermal interface is a generic name of materials applied between the heating device and the heat dissipation component and used as an intermediate layer to replace air at a contact interface gap to reduce contact thermal resistance, and mainly comprises heat-conducting silicone grease, a heat-conducting gasket, heat-conducting glue, heat-conducting paste, a phase-change material, a graphite sheet and the like.

Liquid metal refers to a metal in an amorphous, flowable liquid state, which can be viewed as a mixture of a positive ionic fluid and a free electron gas, such as mercury, gallium, indium, rubidium, cesium, and other low melting point metals and alloys thereof, which generally have excellent thermal and electrical properties.

In order to achieve the purpose, the invention adopts the following technical scheme:

an inner packaging self-adaptive temperature-equalizing thermal interface based on liquid metal infiltration comprises a main body surface of a heat dissipation component and a micro-nano composite structure formed on the main body surface of the heat dissipation component; the micro-nano composite structure comprises a micrometer mastoid array and liquid metal, wherein the liquid metal is packaged in the gap of the micrometer mastoid array.

In order to break through the limit of the heat conducting performance of the existing thermal interface material and greatly reduce the cost burden, the assembly difficulty and the operation and maintenance risks caused by the 'external' design, the invention directly packages liquid metal into the gaps of the micro mastoid arrays by regulating and controlling the infiltration property of the micro mastoid arrays on the surface of the main body of the heat dissipation component to obtain the thermal interface integrated with the heat dissipation component.

After the thermal interface and the heating device are tightly assembled, the packaging liquid metal which is solid at normal temperature is heated and melted into liquid, the volume of the packaging liquid metal slightly expands, the packaging liquid metal flows in the gap and quickly fills a contact gap (self-adaption) to remove air, and the thermal resistance is greatly reduced; meanwhile, when the liquid metal is heated to generate solid-liquid phase change, instantaneous latent heat absorption is carried out, the temperature is maintained near the melting point, and quick temperature equalization is realized; because the micron mastoid array in the micro-nano composite structure still belongs to the main body of the heat dissipation component, the thermal interface can finally obtain the ultrahigh heat conduction efficiency close to the material of the main body of the heat dissipation component. Taking the most common red copper heat dissipation plate as an example, the thermal interface of the invention can generally realize 370Wm^-1 K^-1The thermal conductivity is far higher than that of the prior thermal interface material (less than 100W m)^-1K^-1)。

Meanwhile, the liquid metal is internally packaged in the thermal interface, so that the leakage-proof effect is good and the performance is stable. The 'built-in' packaging design is isolation and protection of liquid metal and complex external environment; in addition, the infiltration property of the super-hydrophilic liquid metal of the micro mastoid array and the inherent boundary pressure and the like when the super-hydrophilic liquid metal is installed along with a heat dissipation component block the lateral leakage loss of the liquid metal together, and the hidden trouble of short circuit is avoided.

In practical applications, the heat dissipation component and the heat generating device may be completely separated, but some heat generating devices (such as CPU, GPU, MaPU, and other chips) actually have their own heat dissipation housings, and it will be understood by those skilled in the art that it is obvious that a thermal interface with the same form or function as that of the present invention may also be provided on the surface of the heat dissipation housing of the heat generating device, and the present invention is not limited to the connection form of the heat dissipation component and the heat generating device.

Preferably, the height of the single micrometer mastoid is 5-500 μm, the equivalent diameter is 10-1000 μm, and the distance between adjacent micrometer mastoids is 10-1000 μm.

Preferably, the height of the single micrometer mastoid is 10-400 μm, the equivalent diameter is 30-800 μm, and the distance between adjacent micrometer mastoids is 30-800 μm.

More preferably, the height of the individual micrometer mastoids is 30 to 300 μm, the equivalent diameter is 50 to 500 μm, and the distance between adjacent micrometer mastoids is 50 to 500 μm.

Further preferably, the height of the single micrometer mastoid is 50 μm to 200 μm, the equivalent diameter is 100 μm to 200 μm, and the distance between the adjacent micrometer mastoids is 100 μm to 200 μm.

Preferably, the micro-papillary surface has a particulate, clustered, fibrous, or convoluted nanotopography; the nano-morphology of the surface of the micrometer mastoid can increase the adhesion force when the liquid metal is packaged, so that the liquid metal completely infiltrates the surface of the micrometer mastoid.

Preferably, the diameter of the particulate or clustered nanotopography is 5nm to 500nm, the length of the fibrous nanotopography is 5nm to 500nm, and the thickness of the corrugated nanotopography is 5nm to 500 nm.

More preferably, the diameter of the particulate or clustered nanotopography is 10nm to 400nm, the length of the fibrous nanotopography is 10nm to 400nm, and the thickness of the corrugated nanotopography is 10nm to 400 nm.

Further preferably, the diameter of the particulate or clustered nanotopography is 30nm to 300nm, the length of the fibrous nanotopography is 30nm to 300nm, and the thickness of the corrugated nanotopography is 30nm to 300 nm. The height of the micrometer mastoid determines the thickness of the liquid metal packaged in the micrometer mastoid array gap, and the liquid metal with the thickness of 5-500 mu m can be obtained based on the process technology, which is the ultrathin thickness which can not be realized by an 'external' thermal interface, so the material consumption is economical, and the cost is lower.

The spacing between adjacent papillae is 10 μm to 1000 μm, which, as will be appreciated by those skilled in the art, determines the size of the gaps in the array of papillae.

Preferably, the melting point of the liquid metal is higher than room temperature but lower than the stable operating temperature of the heat generating device. Therefore, the liquid metal in the thermal interface is solid at normal temperature and is converted into liquid when in a working state, gas is removed, phase change heat absorption is realized, thermal resistance is reduced, rapid temperature equalization is realized, and ultrahigh heat conduction efficiency is obtained.

Preferably, the liquid metal is selected from gallium, indium, tin, bismuth or alloys thereof, or doped mixtures thereof with other metals, oxides of other metals, non-metals or non-metal oxides; the other metal is selected from copper, aluminum, gold, silver, tungsten, rhodium or iridium, and the nonmetal is carbon or silicon.

Further preferably, the carbon includes, but is not limited to, diamond, graphene, or carbon nanotubes, etc.

The purpose of doping other substances in the liquid metal is to adjust the melting point of the liquid metal, so that the liquid metal can be solid at normal temperature and liquid at a working state. In order to match with heating devices with different operating temperatures, in practical application, the components and proportions of the elements in the doping mixture are arbitrary components and proportions which meet requirements.

The liquid metal is doped with other substances only for adjusting the melting point, and compared with the prior art which needs to add expensive auxiliary agents to improve the performance of the liquid metal, the liquid metal is lower in cost.

Preferably, the interstices of the array of micro mastoids are entirely filled with liquid metal. In order to furthest eliminate the air in the thermal interface and the heating device, the packaging liquid level of the liquid metal is equal to the height of the micrometer mastoid, namely, the gap is completely filled with the liquid metal, so that the flatness of the thermal interface is ensured, and the error is not more than +/-0.5 mm.

Preferably, the surface of the micro mastoid array has the wetting property of the super-parent liquid metal, namely the static contact angle of the liquid metal droplets in air or an oxygen-free environment is less than 10 degrees, and the surface of the micro mastoid array forms a uniform liquid metal layer after being wetted by the liquid metal.

Preferably, the heat dissipation component body comprises copper or an alloy thereof, aluminum or an alloy thereof, gold, silver, iron or an alloy thereof, stainless steel, silicon or an oxide thereof, or a doped semiconductor thereof; the heat dissipation part is in a specific form including but not limited to a fin, a heat sink, a heat pipe, a cold plate, a vapor chamber and the like.

The preparation method of the inner packaging self-adaptive uniform-temperature thermal interface based on liquid metal infiltration comprises the following steps: the surface of the main body of the heat dissipation part is etched to form a micrometer mastoid array, the infiltration property of the micrometer mastoid array is regulated and controlled, and the liquid metal is packaged.

Preferably, the etching method for etching the surface of the heat dissipation component body to form the micrometer mastoid array includes, but is not limited to, electrochemical etching, chemical etching, 3D printing, plasma etching, photolithography or laser integrated etching. The technical scheme capable of meeting the requirement of the size of the micrometer mastoid array in a large range is laser integrated etching, which is referred to an issued patent of the applicant (application publication number CN 109974512A).

The purpose of regulating and controlling the infiltration property of the micro mastoid array is to ensure that the micro mastoid structure on the surface of the main body of the heat dissipation component obtains the property of super-hydrophilic liquid metal (easy to infiltrate and spread), so that the liquid metal can infiltrate the micro mastoid uniformly and completely fill the array gap. Preferably, the method for regulating the infiltration property of the micrometer mastoid array comprises but is not limited to chemical reagent modification, functional medium deposition, plasma treatment, ozone treatment or ultraviolet irradiation and the like.

Further preferably, the chemical agent used for the chemical agent modification includes, but is not limited to, for example, sodium hydroxide, potassium hydroxide, hydrofluoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, hydrogen peroxide, sodium persulfate, organosilanes, ionic liquids, and the like. Preferably, the functional medium is deposited by a method including, but not limited to, chemical vapor deposition, physical vapor deposition, vacuum evaporation, atomic layer deposition, or the like.

Preferably, the liquid metal package comprises the steps of: preheating the micrometer mastoid array, infiltrating and filling the molten liquid metal into the gap of the micrometer mastoid array, and then cooling and solidifying to finish the packaging of the liquid metal;

preferably, preheating the micro-mastoid array to 20 ℃ and above the melting temperature of the liquid metal prevents the liquid metal from partially or completely solidifying and interfering with or retarding its wetting fill in the array gaps.

When the liquid metal is a metal simple substance or an alloy, the infiltration process can be directly carried out after the liquid metal is melted; if the liquid metal is a doped mixture, the metal simple substance or alloy needs to be heated and melted first, then other metal or nonmetal substances to be doped are supplemented, and meanwhile, the metal simple substance or alloy is fully and uniformly mixed by using methods such as physical grinding or mechanical stirring and the like for use.

Preferably, the liquid metal infiltration filling method includes, but is not limited to, natural infiltration filling, vacuum or pressure assisted infiltration filling, optical or electric or magnetic induced infiltration filling, and the like.

Preferably, the temperature of the reduced temperature solidification is at least 5 ℃ below the solidification temperature of the liquid metal, ensuring complete solidification of the liquid metal.

The inner packaging self-adaptive uniform temperature thermal interface based on liquid metal infiltration is definitely suitable for any use occasion related to the traditional 'external' thermal interface, and can widely meet the application requirements in the fields of electronic information, aerospace thermal control, advanced energy and the like.

The invention has the following beneficial effects:

according to the inner-packaging self-adaptive temperature-equalizing thermal interface based on liquid metal infiltration, the liquid metal in the thermal interface is directly packaged to the surface of the main body of the heat dissipation component, and when the liquid metal is heated and melted, the liquid metal can automatically fill the contact gap to be tightly attached to the heating device, so that the temperature is quickly equalized, and the ultrahigh heat conduction efficiency close to the material quality of the main body of the heat dissipation component is obtained.

Meanwhile, the thermal interface is low in cost, convenient to disassemble and assemble, stable in performance, good in leakage-proof effect, and capable of being applied to any scene and matched with different heat dissipation components, so that the thermal interface has a good application prospect.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of an inner-package adaptive uniform-temperature thermal interface heat dissipation system based on liquid metal infiltration.

Fig. 2 shows a macroscopic surface schematic diagram of an inner packaging adaptive isothermal thermal interface based on liquid metal infiltration.

Fig. 3 shows a front view of an enlarged section of a micro-nano composite structure micro-area.

Fig. 4 shows a micro-nano composite structure micro-area enlarged surface top view.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below with reference to preferred embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

The structure of the inner-packaging self-adaptive uniform-temperature thermal interface based on liquid metal infiltration prepared in the embodiment of the invention is shown in fig. 1-4, wherein 1-thermal interface; 2-heat dissipation components; 3-a heat generating device; 4-a heat-dissipating member body surface; 5-micro-nano composite structure; 6-micron mastoid; 7-micron papilla array spacing; 8-liquid metal.

Example 1

Selecting red copper with the thickness of 2mm (the thermal conductivity is about 400W m)^-1K^-1) The plate is a heat-dissipating component and elemental gallium (melting point about 30 ℃ C., thermal conductivity about 29W m) is used^-1K^-1) For internally packaging liquid metal, a series of internally packaged self-adaptive uniform-temperature thermal interfaces based on liquid metal infiltration are prepared, and the specific scheme is as follows:

integrally etching the micrometer mastoid array by laser in 2cm × 2cm area, wherein the micrometer mastoid has height of about 5 μm, 15 μm, 25 μm, 35 μm, and 45 μm, the equivalent diameter of cylindrical micrometer mastoid is about 30 μm, and the surface of micrometer mastoid has wrinklesThe thickness of the shape nano-topography is about 500nm and the distance between adjacent micro-mastoids is about 30 μm. Preparing 1.0mol L^-1Regulating and controlling the infiltration property of the micrometer mastoid array by using a sodium hydroxide solution, electrically inducing (with direct current voltage of 5.0V) elemental gallium to infiltrate and fill gaps of the micrometer mastoid array in a constant-temperature water bath heating environment at 50 ℃ (20 ℃ higher than the melting temperature of liquid metal), uniformly packaging, and naturally cooling and curing for 12 hours at a room temperature of 25 ℃ (5 ℃ lower than the solidification temperature of the liquid metal).

In this embodiment, the thermal conductivities of the internal package adaptive uniform-temperature series thermal interfaces based on liquid metal infiltration obtained by testing at 50 ℃ are 394.0W m respectively^-1K^-1、393.2W m^-1K^-1、392.7W m^-1K^-1、391.8W m^-1K^-1、390.8W m^-1K^-1。

The inner-packaging self-adaptive temperature equalization series thermal interface prepared by the embodiment based on liquid metal infiltration can complete the uniform temperature distribution of the 2cm multiplied by 2cm area within 3s in an environment of 50 ℃, and is simply and mechanically fastened (weight of 100 g) with a monocrystalline silicon wafer (simulated heating device) with the length, width and height of 2cm multiplied by 0.5mm, and the monocrystalline silicon wafer is placed in a constant-temperature drying box of 50 ℃ and continuously heated for 12 hours without the liquid metal leaking and oozing.

In this embodiment, the main body of the heat dissipation component is made of the most common red copper (i.e. pure copper), the liquid metal is the simplest gallium simple substance, and the inner-packaging liquid metal only forms an ultra-thin layer with a thickness of less than 50 μm, which fully embodies the advantages of economical material, low cost, and the like.

Example 2

Selecting a red copper plate with the thickness of 2mm as a heat dissipation part, using an indium-tin-bismuth alloy (50% of indium, 20% of tin, 30% of bismuth and about 60 ℃ of melting point) as an inner packaging liquid metal, and doping diamond carbon powder (the average particle size is 50 mu m, the thermal conductivity is about 500W m) with different mass specific gravities of 0:10, 1:9, 3:7 and 5:5^-1K^-1) A series of inner packaging self-adaptive uniform-temperature thermal interfaces based on liquid metal infiltration are prepared, and the specific scheme is as follows:

preparing micro-nano mastoid array by 3D printing in a 3cm multiplied by 3cm area, wherein the height of the micro-emulsion is 200 mu m, and the micro-emulsion is conical micro-emulsionThe equivalent diameter of the mastoid is about 100 μm, the diameter of the particle-shaped nanometer morphology on the surface of the micrometer mastoid is about 50nm, and the distance between the adjacent micrometer mastoids is about 150 μm. Preparing 1.0mol L^-1Regulating and controlling the infiltration property of the micrometer mastoid array by hydrochloric acid, and mechanically stirring and uniformly mixing the indium tin bismuth alloy and the doped diamond carbon powder with different mass proportions of 0:10, 1:9, 3:7 and 5:5 for 2 hours at the constant temperature of 100 ℃ in an oil bath heating environment by using 500r/min to obtain a prefabricated liquid metal doped mixture. Vacuum-assisted (vacuum degree 100Pa) in an environment of heating in a constant-temperature water bath at 80 ℃ (20 ℃ higher than the melting temperature of the liquid metal) to infiltrate and fill the gap of the micrometer mastoid array, and after uniform packaging, cooling and solidifying for 2h in an environment of refrigerating at 0 ℃ (60 ℃ lower than the solidification temperature of the liquid metal).

The inner packaging adaptive temperature equalization series thermal interface based on liquid metal infiltration of the embodiment is tested at the temperature of 80 ℃ to obtain nearly consistent thermal conductivity 383.2W m^-1K^-1、383.7W m^-1K^-1、384.0W m^-1K^-1、384.5W m^{- 1}K^-1. The purpose of the doping mixing of this example from a side view for the purposes of the present invention is merely to adjust the melting point and not to directly contribute to the ultra high thermal conductivity efficiency.

The inner-packaging self-adaptive temperature equalization series thermal interface prepared by the embodiment can complete uniform temperature distribution in a 3cm multiplied by 3cm area within 10s in an environment of 80 ℃, is simply and mechanically fastened (weight of 100 g) with a monocrystalline silicon wafer (simulated heating device) with the length, width and height of 3cm multiplied by 0.5mm, and is placed in a 100 ℃ constant temperature drying box to be heated for 30 days without liquid metal side leakage and seepage.

Example 3

A red copper plate with the thickness of 5mm is selected as a heat dissipation part, gallium-indium alloy (gallium content is 25%, indium content is 75%, melting point is about 90 ℃) is used as inner packaging liquid metal, a series of inner packaging self-adaptive uniform-temperature thermal interfaces based on liquid metal infiltration are prepared, and the specific scheme is as follows:

the laser integrated etching is combined with electrochemical corrosion in a 3cm multiplied by 3cm area (voltage is 5.0V, electrolyte is 0.5mol L)^-1Sulfuric acid and 0.5mol L^-1Copper sulfate solutionLiquid) to prepare a micro-mastoid array, wherein the height of the micro-mastoid is 500 μm, the equivalent diameter of the cubic micro-mastoid is about 100 μm, 300 μm and 700 μm respectively, the length of the fibrous nano-morphology on the surface of the micro-mastoid is only about 5nm, and the distance between adjacent micro-mastoids is about 100 μm. The method comprises the steps of depositing an ultrathin titanium dioxide coating through an atomic layer, and continuously irradiating for 1h by using an ultraviolet light source with the wavelength of 365nm to finish the regulation and control of the infiltration property of the micrometer mastoid array. Melting the liquid metal alloy in a constant temperature oil bath heating environment of 120 ℃ (30 ℃ higher than the melting temperature of the liquid metal) to naturally infiltrate and fill the gap of the micrometer mastoid array, uniformly packaging, and cooling and solidifying for 1h in a freezing environment of-10 ℃ (100 ℃ lower than the solidification temperature of the liquid metal).

In this embodiment, the thermal conductivities of the internally-packaged adaptive uniform-temperature series thermal interfaces based on liquid metal infiltration, which are obtained by testing at 100 ℃ are 374.5W m respectively^-1K^-1、382.5W m^-1K^-1、387.0W m^-1K^-1. This example further demonstrates that the micro mastoid array is a major contributor to the ultra-high thermal conductivity efficiency for the present invention.

In this embodiment, the liquid metal infiltration-based inner-package adaptive uniform-temperature-series thermal interface can complete uniform temperature distribution in a 3cm × 3cm area within 8s in an environment of 100 ℃, and is simply and mechanically fastened (weight of 100 g) to a monocrystalline silicon wafer (simulated heating device) with a length, a width and a height of 3cm × 3cm × 0.5mm, and then placed in a 120 ℃ constant-temperature drying oven to be continuously heated for 30d without liquid metal side leakage and seepage.

Example 4

Selecting 0.5mm aluminum sheet (thermal conductivity about 235W m)^-1K^-1) 0.5mm silicon wafer (thermal conductivity about 150W m)^-1K^-1) 0.5mm iron plate (thermal conductivity about 80W m)^-1K^-1) For a heat dissipation part, indium tin bismuth alloy (indium 50%, tin 20%, bismuth 30%, melting point about 60 ℃) is used as inner packaging liquid metal, a series of inner packaging self-adaptive uniform-temperature thermal interfaces based on liquid metal infiltration are prepared, and the specific scheme is as follows:

the method comprises the steps of respectively obtaining the aluminum, silicon and iron surface micrometer mastoid arrays in a 2cm multiplied by 2cm area through electrochemical (anodic oxidation) corrosion, a traditional photoetching technology and laser integrated etching, wherein the height of the micrometer mastoid is 50 micrometers, the equivalent diameter of the conical micrometer mastoid is about 30 micrometers, the thickness of the corrugated nanometer appearance on the surface of the micrometer mastoid is about 5-50 nm, and the distance between adjacent micrometer mastoids is 30 micrometers. Plasma treatment (power 200W, duration 1200s) is utilized to regulate and control the infiltration property of the micro mastoid array on the surfaces of the aluminum sheet and the iron sheet, and a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a ratio of 3:1 is prepared to regulate and control the infiltration property of the micro mastoid array on the surfaces of the silicon wafers. Melting the liquid metal alloy in a 80 ℃ constant-temperature water bath heating environment (20 ℃ higher than the melting temperature of the liquid metal), naturally infiltrating and filling the micrometer mastoid array gaps, uniformly packaging, and then cooling and solidifying for 2 hours in a 0 ℃ cold storage environment (60 ℃ lower than the solidification temperature of the liquid metal).

In this embodiment, the thermal conductivities of the internal package adaptive uniform-temperature series thermal interfaces based on liquid metal infiltration, which are obtained by testing at 80 ℃ are 223.5W m^-1K^-1、144.6W m^-1K^-1、77.0W m^-1K^-1And the temperature in the 2cm multiplied by 2cm area can be uniformly distributed in 1s, 4s and 8s respectively under the environment of 80 ℃. The embodiment further proves that the invention can realize rapid temperature equalization and obtain ultrahigh heat conduction efficiency close to the materials of the main bodies of different heat dissipation parts.

Example 5

Selecting commercial heat dissipation parts such as a heat sink (made of aluminum alloy), a vapor chamber (made of copper), a heat pipe (made of copper and provided with a plane base) and the like with fins, and using elemental gallium (with the melting point of about 30 ℃ and the thermal conductivity of about 29W m)^-1K^-1) For internally packaging liquid metal, a series of internally packaged self-adaptive uniform-temperature thermal interfaces based on liquid metal infiltration are prepared, and the specific scheme is as follows:

the micrometer mastoid array is integrally etched through laser, wherein the height of the micrometer mastoid is 50 micrometers, the equivalent diameter of the conical micrometer mastoid is about 30 micrometers, the thickness of the wrinkle-shaped nanometer morphology on the surface of the micrometer mastoid is about 500nm, and the distance between adjacent micrometer mastoids is 30 micrometers. Preparing 1.0mol L^-1Regulating and controlling the infiltration property of the sodium hydroxide solution to the micrometer mastoid array, and electrifying in a 50 ℃ constant-temperature water bath heating environment (20 ℃ higher than the melting temperature of liquid metal)Inducing (direct current voltage 5.0V) simple substance gallium to infiltrate and fill the gap of the micrometer mastoid array, uniformly packaging, and cooling and solidifying for 1h in a freezing environment at-10 ℃ (30 ℃ lower than the solidification temperature of liquid metal).

In this embodiment, the liquid metal infiltration-based inner-package adaptive uniform-temperature-series thermal interface is difficult to directly measure the thermal conductivity due to the complex shape of the supported actual heat dissipation part, but the temperature uniform distribution of a 2cm × 2cm area can be completed within 5s in an environment of 50 ℃, and after being simply and mechanically fastened (weight of 100g and weight is pressed) with a monocrystalline silicon wafer (simulated heating device) with the length, width and height of 2cm × 2cm × 0.5mm, the monocrystalline silicon wafer is placed in a 120 ℃ constant-temperature drying box and continuously heated for 30d, and no liquid metal is leaked and oozed out. The embodiment proves that the invention has the characteristics of convenient assembly and disassembly, strong universality, natural leakage prevention and the like.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications belonging to the technical solutions of the present invention are within the scope of the present invention.