Preparation method of interface material for enhancing radiation heat dissipation of high-power electronic device

Abstract

The application provides a preparation method of an interface material for enhancing radiation heat dissipation of high-power electronic devices, and relates to the technical field of high-power electronic device heat management, and comprises the following steps: plating a catalyst layer on the surface of diamond; after heat treatment, placing the diamond with the metal nanoparticle layer on the surface into a chemical vapor deposition system, and introducing carbon-containing gas to grow vertical carbon nanotubes, to obtain a carbon nanotube / diamond interface material. The method realizes the growth of the vertical carbon nanotube array on the diamond, and the prepared carbon nanotube / diamond interface material has good interface combination, high heat transfer rate and good mechanical strength. The vertical carbon nanotube has the super-black characteristic of high emissivity, the diamond can quickly disperse the heat of the heat source in the process of heat dissipation, and then the heat is radiated away through the vertical carbon nanotube; using the diamond / carbon nanotube interface material as a heat dissipation fin can make the high-power electronic device have better heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for high-power electronic devices, and more specifically to a method for preparing an interface material that enhances the radiative heat dissipation of high-power electronic devices. Background Technology

[0002] Power devices, as a crucial component of electronic systems, play a vital role in various electronic devices and systems, with extremely wide applications. High-power electronic devices generate a large amount of heat; if the heat dissipation is ineffective, prolonged exposure to overheating environments can lead to device fatigue and aging, severely shortening the lifespan of electronic devices. Therefore, designing effective heat dissipation materials to solve the heat dissipation problem of high-power electronic devices is particularly important. There are three main ways in which power devices transfer heat to their surroundings: conduction, convection, and radiation. Thermal radiation relies on the rays emitted by the object itself to conduct heat energy; it does not require any medium and is directional and selective. Thermal radiation heat sinks are designed and manufactured based on thermal radiation, offering advantages such as high heat dissipation efficiency and high reliability. According to the Stefan-Boltzmann law for calculating radiative heat dissipation efficiency:

[0003]

[0004] It can be seen that the closer the emissivity ɛ (0 < ɛ ≤ 1) of an object is to 1, the higher its radiation heat dissipation efficiency.

[0005] Carbon nanotubes (CNTs) are one-dimensional nanomaterials with an sp² hybrid structure, theoretically formed by rolling up single or multiple layers of graphite sheets. Their unique structure endows them with excellent electrical conductivity, high mechanical strength (tensile strength 100 GPa, modulus 1 TPa), and high thermal conductivity (3000 W·m⁻¹ K⁻¹). Among all known materials, CNTs best meet the requirements of blackbody materials, with an emissivity closest to 1. Diamond is the best thermally conductive material in nature, achieving a thermal conductivity of 2000 W·m⁻¹ K⁻¹ at room temperature, five times that of copper, while also exhibiting a low coefficient of thermal expansion and low density. Therefore, combining diamond with carbon nanotubes to prepare carbon nanotube / diamond composites holds promise for solving the radiative heat dissipation problem in high-power electronic devices. Summary of the Invention

[0006] This invention provides a method for preparing an interface material that enhances the radiative heat dissipation of high-power electronic devices, thereby solving the technical problems of poor heat dissipation capacity and poor interfacial bonding in existing composite heat dissipation materials.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] A method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices includes the following steps;

[0009] S1. Take the pretreated diamond and perform hydrogen plasma etching on one side of the diamond.

[0010] S2. A catalyst layer is deposited on the surface of the diamond after step S1 to obtain a diamond with a catalyst layer.

[0011] S3. The diamond with the catalyst layer is heat-treated in a mixed atmosphere of argon and hydrogen to obtain a diamond with a metal nanoparticle layer on its surface.

[0012] S4. Place the diamond with the metal nanoparticle layer on its surface into a chemical vapor deposition system and introduce carbon-containing gas to grow vertical carbon nanotubes. In order to ensure that the diamond sample with grown carbon nanotubes is flat enough, the surface roughness of the diamond is required to be less than 1 nm, so as to obtain an interface-strengthened carbon nanotube / diamond interface material.

[0013] The growth of vertical carbon nanotubes comprises a first-stage growth and a second-stage growth. In the first-stage growth, the flow ratio of hydrogen, argon, and acetylene is 5:4-6:5-6, the holding temperature is 680-700℃, and the growth time is 20-30 minutes. In the second-stage growth, the flow ratio of hydrogen, argon, and acetylene is 5:4-6:10, the holding temperature is 680-700℃, and the growth time is 10-20 minutes. Only by dividing the chemical vapor deposition (CVD) growth of carbon nanotubes into two stages can vertical carbon nanotubes be obtained.

[0014] Preferably, the pretreatment in S1 includes cutting, grinding, polishing, pickling and ultrasonic cleaning, and the surface roughness after mechanical polishing is less than 1 nm.

[0015] Preferably, the cleaning solution used in the pickling and ultrasonic cleaning process is a mixed acid solution of HNO3 and H2SO4 in a volume ratio of 1:3.

[0016] Preferably, the hydrogen plasma etching described in S1 is performed using ICP plasma etching.

[0017] Preferably, in the hydrogen plasma etching process described in S1, the hydrogen flow rate is 20-50 sccm, the power is 100-200 W, and the etching time is 10-30 s.

[0018] Preferably, the method for depositing the catalyst layer in S2 is one of magnetron sputtering, electron beam evaporation, ion beam assisted deposition, and atomic layer deposition.

[0019] Preferably, the catalyst layer in S2 is one of iron, cobalt, and nickel.

[0020] Preferably, the thickness of the catalyst layer is 10-15 nm.

[0021] Preferably, the flow rate ratio of argon to hydrogen in S3 is 3:2.

[0022] Preferably, the heat treatment in S3 has a holding temperature of 400-450℃, a holding time of 30-40 min, and a heat treatment heating rate of 20℃ / min.

[0023] To reduce the reaction between diamond and the metal catalyst and the graphitization of diamond, and to achieve uniform and dense growth of carbon nanotubes, a heat treatment process at a relatively low temperature is required, with a sufficiently rapid heating rate during the rise to the growth temperature.

[0024] In the diamond / carbon nanotube interface material structure obtained by this invention, carbon nanotubes are carried on only one side of the diamond. The diamond / carbon nanotube interface material can achieve interconnection of electronic devices through metal bonding or cementation. During interconnection, the electronic device is bonded or cemented to the side of the diamond that does not carry carbon nanotubes. This allows the diamond layer to promptly conduct heat away when high-power electronic devices generate heat, transferring the heat to the vertical carbon nanotubes, which then radiate it away, effectively solving the problem of radiative heat dissipation in high-power electronic devices.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] Diamond and carbon nanotubes are allotropic. Hydrogen plasma treatment of the diamond surface gives the composite material an excellent interfacial bonding state and good interfacial bonding, which is beneficial to improving the heat transfer performance between diamond and carbon nanotubes and the mechanical strength of the material.

[0027] In this invention, the chemical vapor deposition (CVD) growth of carbon nanotubes is divided into two stages. The growth of vertical carbon nanotube arrays on diamond is achieved by controlling the flow ratio of hydrogen, argon, and acetylene. Vertical carbon nanotubes exhibit super-black properties with high emissivity. Diamond has excellent thermal conductivity, rapidly dispersing heat from the heat source, which is then radiated away through the vertical carbon nanotubes. Using the diamond / carbon nanotube interface material as a heat sink can improve the heat dissipation of high-power electronic devices. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the carbon nanotube / diamond interface material prepared in Example 1;

[0029] Figure 2 Image of the carbon nanotube / diamond interface material sample prepared in Example 1;

[0030] Figure 3SEM image of the carbon nanotube / diamond interface material prepared in Example 1;

[0031] Figure 4 This is a SEM image of the carbon nanotube / diamond interface material prepared in the comparative example. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment provides a method for preparing an interface material that enhances the radiative heat dissipation of high-power electronic devices, including the following steps;

[0035] S1. First, the polycrystalline diamond is cut, ground, and mechanically polished to achieve a surface roughness of 0.85nm. Then, the polished polycrystalline diamond is boiled in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a ratio of 1:3 for 3 hours. After cooling, it is ultrasonically cleaned with acetone, alcohol, and deionized water for 15 minutes in sequence.

[0036] S2. The treated diamond sheet is subjected to hydrogen plasma treatment using an ICP plasma etching machine, with a hydrogen flow rate of 30 sccm, a power of 100 W, and an etching time of 20 s.

[0037] S3. A 10 nm thick Fe catalyst layer was deposited on the treated polycrystalline diamond surface using radio frequency magnetron sputtering. The vacuum degree was 3 × 10⁻⁴ Pa, the radio frequency power was 300 W, and the deposition time was 300 s.

[0038] S4. The Fe-coated polycrystalline diamond obtained above is heat-treated in a tube furnace under a mixed atmosphere of argon and hydrogen. The argon flow rate is 60 sccm and the hydrogen flow rate is 40 sccm. The maximum holding temperature for heat treatment is 450℃, the heat treatment time is 30 min, and the heating rate is 20℃ / min.

[0039] S5. After the heat treatment process, the temperature was rapidly increased until the growth temperature of 680℃ was reached. Hydrogen, argon, and acetylene were then introduced, with a hydrogen flow rate of 100 sccm, an argon flow rate of 120 sccm, and an acetylene flow rate of 100 sccm. The growth time was 20 min. The acetylene flow rate was then adjusted to 200 sccm, and growth continued at 680℃ for another 20 min. After growth, the system was cooled to room temperature, and the sample was removed, ultimately yielding the carbon nanotube / diamond interface material.

[0040] The structural schematic diagram of the carbon nanotube / diamond interface material prepared in this embodiment is shown below. Figure 1 Sample image as follows Figure 2 SEM image as follows Figure 3 ,from Figure 3 It can be seen that vertical carbon nanotubes are grown on the surface of the diamond.

[0041] Example 2

[0042] This embodiment provides a method for preparing an interface material that enhances the radiative heat dissipation of high-power electronic devices, including the following steps;

[0043] S1. First, the (100) single crystal diamond is mechanically polished to a surface roughness value of 0.72 nm. Then, the polished single crystal diamond is boiled in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a ratio of 1:3 for 3 hours. After cooling, it is ultrasonically cleaned with acetone, alcohol and deionized water for 15 minutes in sequence.

[0044] S2. The treated diamond sheet is subjected to hydrogen plasma treatment using an ICP plasma etching machine, with a hydrogen flow rate of 20 sccm, a power of 150 W, and an etching time of 30 s.

[0045] S3. A 15nm thick Ni catalyst layer was deposited on the treated single-crystal diamond surface using radio frequency magnetron sputtering. The vacuum level was 4×10⁻⁴ Pa, the radio frequency power was 200W, and the deposition time was 400s.

[0046] S4. The Ni-plated single-crystal diamond obtained above is heat-treated in a tube furnace under a mixed atmosphere of argon and hydrogen. The argon flow rate is 60 sccm and the hydrogen flow rate is 40 sccm. The maximum holding temperature for heat treatment is 400℃, and the heat treatment time is 40 min.

[0047] S5. After the heat treatment process, the temperature was rapidly increased until the growth temperature of 700℃ was reached. Hydrogen, argon, and acetylene were then introduced, with a hydrogen flow rate of 100 sccm, an argon flow rate of 80 sccm, and an acetylene flow rate of 120 sccm. The growth time was 30 min. The acetylene flow rate was then adjusted to 200 sccm, and growth continued at 700℃ for another 10 min. After growth, the system was cooled to room temperature, and the sample was removed, ultimately yielding the carbon nanotube / diamond interface material.

[0048] Example 3

[0049] This embodiment provides a method for preparing an interface material that enhances the radiative heat dissipation of high-power electronic devices, including the following steps;

[0050] S1. First, the (100) single crystal diamond is mechanically polished to a surface roughness value of 0.72 nm. Then, the polished single crystal diamond is boiled in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a ratio of 1:3 for 3 hours. After cooling, it is ultrasonically cleaned with acetone, alcohol and deionized water for 15 minutes in sequence.

[0051] S2. The treated diamond sheet is subjected to hydrogen plasma treatment using an ICP plasma etching machine, with a hydrogen flow rate of 50 sccm, a power of 200 W, and an etching time of 10 s.

[0052] S3. A 13 nm thick cobalt catalyst layer was deposited on the treated single-crystal diamond surface using radio frequency magnetron sputtering. The vacuum degree was 4 × 10⁻⁴ Pa, the radio frequency power was 200 W, and the deposition time was 400 s.

[0053] S4. The cobalt-coated single-crystal diamond obtained above is heat-treated in a tube furnace under a mixed atmosphere of argon and hydrogen. The argon flow rate is 60 sccm and the hydrogen flow rate is 40 sccm. The maximum holding temperature for heat treatment is 420℃, and the heat treatment time is 35 min.

[0054] S5. After the heat treatment process, the temperature was rapidly increased until the growth temperature of 690℃ was reached. Hydrogen, argon, and acetylene were then introduced, with hydrogen flow rates of 100 sccm, argon flow rates of 100 sccm, and acetylene flow rates of 110 sccm. The growth time was 25 min. The acetylene flow rate was then adjusted to 200 sccm, and growth continued at 690℃ for another 15 min. After growth, the system was cooled to room temperature, and the sample was removed, ultimately yielding the carbon nanotube / diamond interface material.

[0055] Comparative Example

[0056] This comparative example is similar to Example 1, except that in this comparative example, in step S5, after the heat treatment process, the temperature is rapidly increased. After reaching the growth temperature of 680°C, hydrogen, argon, and acetylene are introduced, with hydrogen flow rates of 100 sccm, argon flow rates of 120 sccm, and acetylene flow rates of 100 sccm. The growth time is 40 min, allowing for one-step direct growth of carbon nanotubes on diamond. The SEM image of the carbon nanotube / diamond interface material prepared in this comparative example is shown below. Figure 4 As shown, the carbon nanotubes grown on the diamond surface in this comparative example are not vertical structures.

[0057] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an interface material to enhance radiative heat dissipation in high-power electronic devices, characterized in that, Includes the following steps; S1. Take the pretreated diamond and perform hydrogen plasma etching. During the hydrogen plasma etching process, the hydrogen flow rate is 20-50 sccm, the power is 100-200w, and the etching time is 10-30s. S2. A catalyst layer is deposited on the surface of the diamond after step S1 to obtain a diamond with a catalyst layer, wherein the catalyst layer is one of iron, cobalt and nickel. S3. The diamond with the catalyst layer is heat-treated in a mixed atmosphere of argon and hydrogen to obtain a diamond with a metal nanoparticle layer on the surface. The heat treatment temperature is 400-450℃, the heat treatment time is 30-40min, and the heat treatment heating rate is 20℃ / min. S4. Place the diamond with the metal nanoparticle layer on its surface into a chemical vapor deposition system and introduce carbon-containing gas to grow vertical carbon nanotubes to obtain a carbon nanotube / diamond interface material. The growth of the vertical carbon nanotubes includes a first stage growth and a second stage growth. In the first stage growth, the flow ratio of hydrogen, argon and acetylene is 5:4-6:5-6, the holding temperature is 680-700℃, and the growth time is 20-30 min. In the second stage growth, the flow ratio of hydrogen, argon and acetylene is 5:4-6:10, the holding temperature is 680-700℃, and the growth time is 10-20 min.

2. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 1, characterized in that, The pretreatment described in S1 includes cutting, grinding, polishing, pickling, and ultrasonic cleaning.

3. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 2, characterized in that, The cleaning solution used in the pickling and ultrasonic cleaning process is a mixed acid solution of HNO3 and H2SO4 in a volume ratio of 1:

3.

4. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 1, characterized in that, The hydrogen plasma etching described in S1 uses ICP plasma etching.

5. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 1, characterized in that, The catalyst layer deposition method described in S2 is one of magnetron sputtering, electron beam evaporation, ion beam assisted deposition, or atomic layer deposition.

6. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 1, characterized in that, The thickness of the catalyst layer described in S2 is 10-15 nm.

7. The method for preparing an interface material to enhance radiative heat dissipation of high-power electronic devices according to claim 1, characterized in that, The flow rate ratio of argon to hydrogen in S3 is 3:2.

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