Highly reliable insulating coating based on aerosol deposition and process for its production

Abstract

The application discloses a high-reliability insulating coating based on aerosol deposition and a preparation process thereof, and relates to the technical field of insulating coatings. The application deposits inorganic powder on the surface of a copper wire through aerosol deposition technology, and cooperates with a heat treatment process to prepare a high-reliability insulating coating. Through accurate regulation of the powder particle size and deposition parameters, the dielectric strength and electrical performance of the insulating layer are significantly improved, the risk of leakage current is reduced, the corrosion resistance, insulation and mechanical strength of the copper wire are effectively improved, the damage of traditional high-temperature processes to the performance of the copper wire is avoided, and the process is flexible. Mechanical anchoring formed through high-speed impact of aerosol deposition ensures the stability of the coating in a complex environment, has strong adhesion, and effectively prevents the coating from peeling off.

Description

Technical Field

[0001] This invention relates to the field of high voltage-resistant insulating coating technology, specifically a high-reliability insulating coating based on aerosol deposition and its preparation process. Background Technology

[0002] Aerosol deposition technology is an advanced process that forms a dense film by spraying an aerosol containing nanoparticles onto the surface of a substrate under normal or low temperature conditions. Because it avoids the damage of high temperature to heat-sensitive materials, it is more efficient than traditional chemical vapor deposition technology and is applicable to a variety of materials such as metals, ceramics, and carbon nanotubes. It is widely used in many fields such as electronic devices, energy, optics and medicine.

[0003] Insulating coatings effectively isolate copper wires from the external environment or other conductors, preventing short circuits or leakage caused by contact and ensuring the safe operation of electrical equipment. In high-temperature environments, insulating coatings maintain stable insulation performance, preventing copper wire oxidation or insulation failure, resisting physical wear and chemical corrosion, and extending the service life of copper wires. For example, enameled copper wires are used for high-frequency signal transmission, and the insulation layer reduces signal interference.

[0004] Traditional organic coatings require high temperatures or long curing times, resulting in low production efficiency. Insufficient substrate treatment or defects in the internal structure of the coating can lead to problems such as poor coating adhesion, easy peeling, cracking, bubbles, and pinholes. Under high pressure or humid and hot environments, they are prone to partial discharge or insulation failure. Therefore, this invention proposes a high-reliability insulating coating based on aerosol deposition and its preparation process to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a high-reliability insulating coating based on aerosol deposition and its preparation process, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0007] Step 1: Take inorganic powder, dry and screen it to obtain pretreated inorganic powder;

[0008] Step 2: Mix the pretreated inorganic powder with the carrier gas to obtain an aerosol;

[0009] Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating.

[0010] In the aforementioned technical solution, from a microstructural perspective, during the aerosol deposition process, high-speed impacts cause inorganic powder to form a dense accumulation structure on the copper wire surface. This dense structure significantly reduces defects and porosity within the coating, further lowering the risk of leakage current. Simultaneously, the dense structure better prevents the intrusion of corrosive substances such as moisture and oxygen from the external environment, significantly improving the corrosion resistance of the copper wire and extending its service life in harsh environments.

[0011] In terms of thermal stability, coatings formed from inorganic powders exhibit excellent thermal stability. Under high-temperature environments, the coatings maintain their structural and performance stability without decomposition, softening, or deformation. This is crucial for electrical equipment that needs to operate under high-temperature conditions, ensuring safe operation and preventing safety accidents caused by insulation coating failure.

[0012] In terms of mechanical properties, the coating and copper wire are tightly bonded together through a combination of mechanical anchoring and chemical bonding. This bonding method gives the coating high hardness and wear resistance, effectively resisting mechanical damage such as friction and scratches. During the installation and use of electrical equipment, the coating is not easily damaged, ensuring long-term stability of insulation performance.

[0013] Furthermore, the preparation process of this invention also has environmental advantages. The aerosol deposition process does not require the use of large amounts of organic solvents and high-temperature heating, reducing energy consumption and emissions of harmful substances, which aligns with the concept of green manufacturing and is environmentally friendly. At the same time, the flexibility of the process allows for adjustments to coating thickness, performance, and other parameters to meet diverse market demands based on different application requirements.

[0014] Furthermore, the inorganic powder is any one or a mixture of two of silicon dioxide and aluminum oxide.

[0015] Furthermore, the particle size of the inorganic powder is 0.1–10 μm.

[0016] Furthermore, in step one, the drying process conditions are: drying at 60-70℃ for 30-40 minutes.

[0017] Furthermore, the carrier gas is any one or a mixture of two of nitrogen, argon, and helium.

[0018] Furthermore, in step two, the carrier gas flow rate is 10–50 L / min, the temperature is 50–80 °C, and the aerosol concentration is 100–200 mg / m³. 3 The flow rate is 80–120 sccm.

[0019] Furthermore, the aerosol is a mixture of aerosol particles.

[0020] Furthermore, in step three, the pressure in the deposition chamber is maintained at 10–1000 Pa; the deposition rate is 300–400 m / s; the distance between the nozzle and the copper wire is 5–20 mm; and the deposition voltage is 5–15 kV.

[0021] Furthermore, in step four, the heat treatment process conditions are as follows: heat to 200-300℃ at a rate of 1-5℃ / min, hold for 1-2 hours, and air cool to room temperature.

[0022] In the above technical solution, the particle size of the inorganic powder is controlled to ensure that the particles are small and evenly distributed; the powder is dried and screened to remove agglomerated particles and impurities to improve the deposition quality; the carrier gas flow rate is controlled to maintain the concentration and stability of the aerosol; and the pressure in the deposition chamber is controlled to optimize the particle impact effect.

[0023] Secondly, heat treatment after depositing the insulating coating can promote densification between particles during the aerosol deposition process, reduce porosity, and form a denser microstructure. Densification can reduce conductive channels and optimize electrical insulation performance; it can improve the adhesion between the insulating layer and the substrate, reducing the risk of delamination; it can improve the hardness, crack resistance, and wear resistance of the coating; and it can release the internal stress generated during the deposition process, reducing the risk of cracking.

[0024] Furthermore, the inorganic powder is modified alumina.

[0025] Furthermore, the preparation method of modified alumina includes the following processes:

[0026] S1: Take alumina, clean and dry it, mix it with a silane coupling agent, heat it to react, centrifuge to disperse it, and dry it to obtain coupled alumina;

[0027] S2: Mix coupled alumina with tetraethyl orthosilicate, add deionized water, then add polyethylene glycol, adjust the pH, and grind to obtain modified alumina.

[0028] In the above technical solution, alumina is an amphoteric oxide. Aluminum ions have empty orbitals and can accept lone pairs of electrons provided by oxygen atoms in water molecules to form coordinate bonds. Hydrogen atoms in water molecules combine with oxygen atoms around aluminum ions on the surface, thereby introducing hydroxyl groups on the alumina surface. Silane coupling agents are used to modify the alumina surface and generate active sites. The inorganic end (-Si-O-) of the silane coupling agent condenses with the hydroxyl groups on the alumina surface to form Si-O-Al covalent bonds. These covalent bonds have high bond energies, enabling the silane coupling agent to be firmly bound to the alumina surface. At the same time, the other end of the silane coupling agent usually contains an organic functional group (-NH2), which can introduce silica precursors (tetraethyl orthosilicate) to undergo condensation reactions with it.

[0029] Tetraethyl orthosilicate undergoes hydrolysis in water, where the ethoxy group is replaced by a hydroxyl group to generate silanol and ethanol. Under acidic conditions, hydrogen ions promote the departure of the ethoxy group. The silanol produced by hydrolysis has high reactivity. The surface of coupled alumina has organic functional groups (-NH2), which can undergo condensation reactions with silanol to form a three-dimensional silica network structure on the surface of coupled alumina, ultimately achieving silica coating on the alumina surface.

[0030] Both silica and alumina are insulating materials. By modifying alumina, silica can coat it, enhancing the coating's insulation while simultaneously strengthening the interfacial bond between the silica network and the alumina matrix. This effectively prevents coating peeling, thereby improving the hardness, thermal stability, wear resistance, and insulation of the copper wire, meeting the high reliability and high performance requirements of various fields. Surface modification of alumina reduces its surface energy, improves the wettability of aerosol particles, significantly increases deposition efficiency, and enhances adhesion to the copper wire. The difference between physical bonding and chemical bonding between silica and alumina lies in the fact that chemical bonding significantly improves the stability and durability of the coating, exhibiting irreversible characteristics, thus meeting the demands of high-performance materials.

[0031] Furthermore, in step S1, the cleaning process conditions are as follows: cleaning with 1-5% NaOH solution for 10-20 minutes, and drying at 60-70℃ for 20-30 minutes; the heating reaction process conditions are as follows:

[0032] Temperature 70-80℃, time 30-40 min; centrifugal dispersion conditions are 2000-2400 rpm for 10-20 min; drying conditions are 60-70℃ for 20-30 min.

[0033] Furthermore, in step S1, the mass ratio of alumina to silane coupling agent is 1:(5-10).

[0034] Furthermore, the polyethylene glycol is PEG400.

[0035] Furthermore, the silane coupling agent is γ-aminopropyltriethoxysilane (KH-550).

[0036] Furthermore, the particle size of alumina is 0.1–5 μm.

[0037] Furthermore, in step S2, the mass ratio of coupled alumina, tetraethyl orthosilicate, deionized water, and polyethylene glycol is 1:(2-3):(1-2):(0.5-0.8).

[0038] Furthermore, in step S2, the grinding process conditions are as follows: using a ball mill, rotating at 200-300 rpm, dispersing for 10-20 minutes each time, grinding 3-6 times, and adjusting the pH to 4.5-5.5.

[0039] Furthermore, the copper wires undergo plasma cleaning before deposition.

[0040] Furthermore, the plasma cleaning process conditions are as follows: a mixed gas of argon and hydrogen is used as the cleaning gas source, the volume ratio of argon to hydrogen is 95:5, the mixed gas flow rate is 100-200 sccm, the cleaning power is 50-200W, and the cleaning time is 20-30 minutes at room temperature.

[0041] Furthermore, the thickness of the high-reliability insulating coating is 1–50 μm.

[0042] Among the aforementioned technical effects, cleaning the copper wire can remove residual oil and oxides from its surface, which is beneficial for the adhesion and deposition of aerosol particles. This can improve the adhesion and density of the insulation layer, enhance its electrical, mechanical, and protective properties, and extend the service life of the copper wire.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] 1. The high-reliability insulating coating of the present invention uses aerosol deposition technology to mix carrier gas with inorganic powder to obtain mixed aerosol particles, which form an aerosol beam and are deposited on the substrate to form a dense insulating layer. This achieves an insulating layer with high dielectric strength and low leakage current, and is suitable for the fields of electronics, semiconductors and optics, especially for heat-sensitive substrates.

[0045] 2. The high-reliability insulating coating of the present invention significantly improves the dielectric strength and electrical properties of the insulating layer by precisely controlling the powder particle size and deposition parameters, reduces leakage current, and effectively improves the corrosion resistance, insulation and mechanical strength of copper wire. At the same time, it avoids the damage to the copper wire performance caused by traditional high-temperature processes and has the characteristics of flexible process.

[0046] 3. The high-reliability insulating coating of the present invention is mechanically anchored by the high-speed impact of aerosol deposition, ensuring the stability of the coating in complex environments and having strong adhesion.

[0047] 4. The high-reliability insulating coating of the present invention, by modifying alumina, allows silica to coat alumina, which enhances the insulation of the coating and better strengthens the interfacial bonding between materials, thereby improving the hardness, thermal stability, wear resistance and insulation of copper wire, and meeting the high reliability and high performance requirements of various fields. Attached Figure Description

[0048] Figure 1This is a flowchart of the preparation process in the example;

[0049] Figure 2 This is a schematic diagram of the high-reliability insulation layer combined with copper wire in an embodiment.

[0050] Figure 3 and Figure 4 This is a characterization diagram of the high-reliability insulation layer and copper wire bonding structure in an embodiment; Detailed Implementation

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] In the following specific implementation,

[0053] Alumina, average particle size 30nm, purity 99.9%, crystal form α;

[0054] Silica, with an average particle size of 30 nm and a purity of 99.9%;

[0055] Copper wire, cross-sectional area 2.5mm² 2 ;

[0056] The silane coupling agent is γ-aminopropyltriethoxysilane (KH-550);

[0057] Example 1: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0058] Step 1: Take alumina, dry it at 60℃ for 30 min, and screen out alumina with a particle size of 0.5 μm to obtain pretreated alumina;

[0059] Step 2: Mix pretreated alumina with nitrogen to obtain an aerosol; the nitrogen flow rate is 10 L / min, the temperature is 50℃, and the aerosol concentration is 100 mg / m³. 3 The flow rate is 80 sccm;

[0060] Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating; the pressure in the deposition chamber is maintained at 10 Pa; the deposition rate is 300 m / s; the distance between the nozzle and the copper wire is 5 mm; the deposition voltage is 5 kV; the heat treatment process conditions are: heating to 200 °C at a rate of 2 °C / min, holding at that temperature for 1 h, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 20 μm.

[0061] Example 2: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0062] Step 1: Take silica, dry it at 60℃ for 30 min, and screen out silica particles with a diameter of 0.4 μm to obtain pretreated silica;

[0063] Step 2: Mix pretreated silica with nitrogen to obtain an aerosol; the nitrogen flow rate is 10 L / min, the temperature is 50℃, and the aerosol concentration is 100 mg / m³. 3 The flow rate was 90 sccm;

[0064] Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating; the pressure in the deposition chamber is maintained at 100 Pa; the deposition rate is 300 m / s; the distance between the nozzle and the copper wire is 5 mm; the deposition voltage is 10 kV; the heat treatment process conditions are: heating to 200 °C at a rate of 2 °C / min, holding at that temperature for 1.5 h, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 22 μm.

[0065] Example 3: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0066] Step 1: Take silicon dioxide and aluminum oxide, dry them at 65℃ for 30 min, and screen out silicon dioxide and aluminum oxide with a particle size of 0.6 μm to obtain pretreated inorganic powder; the mass ratio of silicon dioxide to aluminum oxide is 1:1.

[0067] Step 2: Mix the pretreated inorganic powder with nitrogen gas to obtain an aerosol; the nitrogen flow rate is 10 L / min, the temperature is 50℃, and the aerosol concentration is 100 mg / m³. 3 The flow rate was 92 sccm;

[0068] Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating; the pressure in the deposition chamber is maintained at 200 Pa; the deposition rate is 350 m / s; the distance between the nozzle and the copper wire is 10 mm; the deposition voltage is 10 kV; the heat treatment process conditions are: heating to 200 °C at a rate of 3 °C / min, holding at that temperature for 1 h, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 25 μm.

[0069] Example 4: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0070] Step 1: Take the modified alumina, dry it at 65℃ for 30 min, and screen out the modified alumina with a particle size of 1.5 μm to obtain the pretreated modified alumina;

[0071] Step 2: Mix the pretreated modified alumina with nitrogen to obtain an aerosol; the nitrogen flow rate is 10 L / min, the temperature is 50℃, and the aerosol concentration is 100 mg / m³. 3 The flow rate was 95 sccm;

[0072] Step 3: Using a mixed gas of argon and hydrogen as the carrier gas, with a volume ratio of 95:5 and a flow rate of 150 sccm, the cleaning power is 100W. Cleaning is performed at room temperature for 20 minutes, followed by drying at 60℃ for 30 minutes. Then, the copper wire is fixed in the deposition chamber, and aerosol is sprayed onto the copper wire surface at room temperature for heat treatment to obtain a high-reliability insulating coating. The pressure in the deposition chamber is maintained at 500 Pa; the deposition rate is 300 m / s; the distance between the nozzle and the copper wire is 15 mm; the deposition voltage is 10 kV; the heat treatment process conditions are: heating to 200℃ at a rate of 3℃ / min, holding at that temperature for 1.5 hours, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 30 μm.

[0073] Step one, the preparation process of modified alumina, includes the following steps:

[0074] S1: Take alumina, wash it with 5% NaOH solution for 20 min, dry it at 70℃ for 30 min, mix it with silane coupling agent, and heat it to 80℃ for 40 min; the centrifugal dispersion process conditions are: disperse at 2400 rpm for 20 min; the drying process conditions are: dry at 70℃ for 30 min to obtain coupled alumina; the mass ratio of alumina to silane coupling agent is 1:8;

[0075] S2: Mix coupling alumina with tetraethyl orthosilicate, add deionized water, then add polyethylene glycol, and use a ball mill at 300 rpm for 20 min each time, milling 6 times, and adjust the pH to 5.5 to obtain modified alumina; the mass ratio of coupling alumina, tetraethyl orthosilicate, deionized water and polyethylene glycol is 1:2:1:0.5.

[0076] Example 5: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0077] Step 1: Take the modified alumina, dry it at 60℃ for 40 min, and screen out the modified alumina with a particle size of 3μm to obtain the pretreated modified alumina;

[0078] Step 2: Mix the pretreated modified alumina with nitrogen to obtain an aerosol; the nitrogen flow rate is 10 L / min, the temperature is 50℃, and the aerosol concentration is 100 mg / m³. 3 The flow rate was 95 sccm;

[0079] Step 3: Using a mixed gas of argon and hydrogen as the carrier gas, with a volume ratio of 95:5 and a flow rate of 150 sccm, the cleaning power is 100W. Cleaning is performed at room temperature for 20 minutes, followed by drying at 60℃ for 30 minutes. Then, the copper wire is fixed in the deposition chamber, and aerosol is sprayed onto the copper wire surface at room temperature for heat treatment to obtain a high-reliability insulating coating. The pressure in the deposition chamber is maintained at 600 Pa; the deposition rate is 390 m / s; the distance between the nozzle and the copper wire is 15 mm; the deposition voltage is 14 kV; the heat treatment process conditions are: heating to 200℃ at a rate of 4℃ / min, holding at that temperature for 1.5 hours, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 40 μm.

[0080] Step one, the preparation process of modified alumina, includes the following steps:

[0081] S1: Take alumina, wash it with 5% NaOH solution for 15 min, dry it at 70℃ for 30 min, mix it with silane coupling agent, and heat it to 80℃ for 40 min; the centrifugal dispersion process conditions are 2400 rpm for 20 min; the drying process conditions are 70℃ for 30 min to obtain coupled alumina; the mass ratio of alumina to silane coupling agent is 1:8.

[0082] S2: Mix coupling alumina with tetraethyl orthosilicate, add deionized water, then add polyethylene glycol, and use a ball mill at 300 rpm for 20 min each time, milling 6 times, and adjust the pH to 5.5 to obtain modified alumina; the mass ratio of coupling alumina, tetraethyl orthosilicate, deionized water and polyethylene glycol is 1:3:2:0.7.

[0083] Comparative Example 1: A method for preparing a high-reliability insulating coating, comprising the following steps:

[0084] Step 1: Take alumina, dry it at 60℃ for 40 min, and screen out alumina with a particle size of 10μm to obtain pretreated alumina;

[0085] Step 2: Using a mixed gas of argon and hydrogen as the carrier gas, with a volume ratio of 95:5, a mixed gas flow rate of 200 sccm, a cleaning power of 200 W, and cleaning at room temperature for 30 min, followed by drying at 70 °C for 30 min, the pretreated alumina is taken and deposited on the surface of the copper wire using physical vapor deposition. The target power is 150 W, the substrate negative bias voltage is -90 V, the argon flow rate is 32 sccm, the working pressure is 0.3 Pa, the deposition time is 20 min, and the insulating coating thickness is 35 μm, resulting in an insulating coated copper wire.

[0086] Comparative Example 2: A process for preparing a high-reliability insulating coating based on aerosol deposition, comprising the following steps:

[0087] Step 1: Take aluminum nitride, dry it at 70℃ for 40 min, and screen out aluminum nitride with a particle size of 8μm to obtain pretreated aluminum nitride;

[0088] Step 2: Mix pretreated aluminum nitride with nitrogen gas to obtain an aerosol; the nitrogen flow rate is 50 L / min, the temperature is 70℃, and the aerosol concentration is 150 mg / m³. 3 The flow rate is 120 sccm;

[0089] Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating; the pressure in the deposition chamber is maintained at 500 Pa; the deposition rate is 300 m / s; the distance between the nozzle and the copper wire is 5 mm; the deposition voltage is 15 kV; the heat treatment process conditions are: heating to 300 °C at a rate of 5 °C / min, holding at that temperature for 2 h, and air cooling to room temperature; the thickness of the high-reliability insulating coating is 45 μm.

[0090] experiment:

[0091] The insulating coatings obtained in Examples 1-5 and Comparative Examples 1-2 were used to prepare samples, and their performance was tested and the test results were recorded.

[0092] Porosity test: Using GB / T 17720-1999 as the reference standard, after cutting the coating sample and preparing the metallographic specimen, the cross section of the coating is observed under an optical microscope or scanning electron microscope. The area of ​​the pores is automatically analyzed and evaluated through image analysis, and the porosity is calculated.

[0093] Peel strength test: The insulation layer and copper wire are peeled off at a speed of 50 mm / min using a tensile testing machine. The force required during the peeling process is measured and the peel strength is recorded.

[0094] Dielectric constant test: A section of copper wire was cut as a sample, with a length of 5cm. The capacitance of the sample was measured using a high-precision LCR meter, and the dielectric constant was calculated.

[0095] Performance Comparison Table

[0096] index Porosity (%) Peel strength (N / mm) Dielectric constant Example 1 0.85 19.8 9.8 Example 2 0.86 21.3 4.5 Example 3 0.82 18.5 9.5 Example 4 0.81 23.2 9.5 Example 5 0.80 23.1 9.4 Comparative Example 1 1.25 12.5 8.7 Comparative Example 2 1.12 13.8 8.8

[0097] Based on the data in the table above, the following conclusions can be clearly drawn:

[0098] The high-reliability insulating coatings obtained in Examples 1-5 are compared with the insulating coatings obtained in Comparative Examples 1-2. The test results show that:

[0099] Compared with the comparative examples, the insulating coatings obtained in Examples 1-5 have lower porosity, higher peel strength, and higher dielectric constant.

[0100] Compared with Example 1, the insulating coating obtained in Comparative Example 1 was prepared by depositing aluminum oxide on the surface of copper wire using physical vapor deposition. The resulting insulating coating had high porosity, low peel strength, and low dielectric constant. It can be seen that the method of using physical vapor deposition instead of aerosol deposition cannot meet the requirement of porosity <1%.

[0101] Compared with Example 1, the insulating coating in Comparative Example 2 uses aluminum nitride instead of aluminum oxide. The resulting insulating coating has low porosity, high peel strength, and low dielectric constant. It can be seen that if aluminum nitride is used as an inorganic powder, it does not have the high density, high peel strength, and good insulation performance of aluminum oxide or silicon dioxide used in this invention.

[0102] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A process for preparing a high-reliability insulating coating based on aerosol deposition, characterized in that: Includes the following steps: Step 1: Take inorganic powder, dry and screen it to obtain pretreated inorganic powder; the inorganic powder is alumina. Step 2: Mix the pretreated inorganic powder with the carrier gas to obtain an aerosol; Step 3: Fix the copper wire in the deposition chamber, spray the aerosol onto the surface of the copper wire at room temperature, and heat treat it to obtain a high-reliability insulating coating; The alumina undergoes surface modification, and the specific process for surface modification is as follows: S1: Take alumina, clean and dry it, mix it with a silane coupling agent, heat it to react, centrifuge to disperse it, and dry it to obtain coupled alumina; S2: Mix coupled alumina with tetraethyl orthosilicate, add deionized water, then add polyethylene glycol, adjust the pH, grind, and obtain modified alumina; In step S1, the mass ratio of alumina to silane coupling agent is 1:(5~10); the silane coupling agent is γ-aminopropyltriethoxysilane; in step S2, the mass ratio of coupling alumina, tetraethyl orthosilicate, deionized water and polyethylene glycol is 1:(2~3):(1~2):(0.5~0.8).

2. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 1, characterized in that: The carrier gas is any one or a mixture of two of nitrogen, argon, and helium.

3. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 1, characterized in that: The inorganic powder has a particle size of 0.1~10μm.

4. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 1, characterized in that: In step two, the carrier gas flow rate is 10~50L / min.

5. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 1, characterized in that: In step three, the pressure in the sedimentation chamber is maintained at 10~1000 Pa; The deposition rate is 300~400 m / s; The distance between the nozzle and the copper wire is 5~20mm, and the deposition voltage is 5~15kV.

6. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 1, characterized in that: The copper wires undergo plasma cleaning before deposition.

7. The preparation process of a high-reliability insulating coating based on aerosol deposition according to claim 6, characterized in that: The plasma cleaning process conditions are as follows: use a mixed gas of argon and hydrogen as the cleaning gas source, with a volume ratio of argon to hydrogen of 95:5, a mixed gas flow rate of 100~200 sccm, a cleaning power of 50~200W, and cleaning for 20~30 minutes at room temperature.

8. A high-reliability insulating coating based on aerosol deposition, characterized in that: Prepared by the preparation process according to any one of claims 1-7.

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