A method for preparing multifunctional nano protective coating by periodic alternating discharge

Abstract

Disclosed is a method for preparing a multi-functional protective nano coating by means of periodic alternating discharge, comprising the steps of: (1) putting a substrate in a reaction cavity of a nano coating preparation device, continuously vacuumizing the reaction cavity such that the degree of vacuum in the reaction cavity reaches 10 to 200 millitorrs, introducing the inert gas He or Ar thereinto, and starting a movement mechanism to make the substrate move in the reaction cavity; (2) introducing monomer vapor into the reaction cavity to reach a degree of vacuum of 30 to 300 millitorrs, and starting plasma discharge for chemical vapor deposition, wherein the deposition process comprises a preprocessing stage and a film-plating stage, in the preprocessing stage, the plasma discharge power is 120 to 400 W, and the discharge duration is 60 to 900 s, then, the film-plating stage is entered, the plasma discharge power is regulated to 50 to 200 W, and the discharge duration is regulated to 600 to 3600 s, the alternating frequency is 1 to 1000 Hz, and a multi-functional nano coating is prepared on a surface of the substrate by means of chemical vapor deposition, the component of the monomer vapor is a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, and the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 to 65%; and (3) stopping the introduction of the monomer vapor while stopping the discharging of plasma, continuing to carry out vacuumization, keeping the reaction cavity at a degree of vacuum of 10 to 200 millitorrs for 1 to 5 min, then introducing the atmosphere to reach atmospheric pressure, stopping the movement of the substrate, and then taking out the substrate.

Description

technical field [0001] The invention belongs to the technical field of plasma chemical vapor deposition, and in particular relates to a method for preparing a multifunctional nano protective coating. Background technique [0002] Corrosive environments are the most common cause of damage to electronic devices. Corrosion of solid materials in electronic devices, reduction of conductor / semiconductor insulation, and fault phenomena such as short circuit, open circuit or poor contact caused by environmental corrosion. At present, in the products of high-tech industries such as national defense and aerospace, the proportion of electronic components is increasing, and the requirements for moisture-proof, mildew-proof and corrosion resistance of electronic products are becoming more and more stringent. In the field of communication, with the continuous advancement of technology, the continuous increase of communication frequency, the heat dissipation of communication equipment, an...

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Problems solved by technology

[0012] The British P2i company has developed a polymer nano-coating based on a specific small duty cycle pulse discharge method using chemical vapor deposition technology. The duty cycle is less than 1:1000. The preparation process of the method can not realize the effective coordination and control of the bond length, bond energy, molecular weight of the material and energy supply of different groups in the chemical raw materials, and the scratch resistance and durability of the prepared coating are not ideal.

It is also due to the performance limitation of the coating that the current coating can only form a lyophobic nano-coating on electronic and electrical equipment, and the corrosion resistance to the environment cannot be effectively solved.

Moreover, the dense protective coating prepared based on a specific small duty cycle pulse discharge method has a fatal disadvantage: from a microscopic point of view, the small power density in the coating process is not conducive to the formation of a dense structure, and even cannot form a stable film. Structure; from a macro point of view, a small power density is not conducive to the large rate growth of the coating, and the efficiency is low in actual production, which limits its application

[0013] In the existing plasma chemical vapor deposition coating preparation process, the substrate is fixed, and the movement state of the substrate has no correlation with the discharge energy of the plasma; the static substrate in the chamber is treated by the continuous discharge method, The activated chain scission in the monomer is generally combined into a film through simple stacking under the action of continuous discharge, and the resulting coating generally has a loose structure, or even a high degree of powderization, which is not conducive to the formation of a microscopic dense structure of the coating. Therefore, the coating's Waterproof, moisture-proof, corrosion-resistant, solvent-resistant and other protective properties are poor

[0014] Due to the regional differences in plasma density and chemical raw material density in the reaction chamber, the static substrate will also lead to slow coating deposition in some areas, low production efficiency, and there are also large differences in uniformity and compactness.

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