WO2018214451A1

WO2018214451A1 - Method for preparing multi-functional protective nano coating by means of cyclical periodic alternating discharge

Info

Publication number: WO2018214451A1
Application number: PCT/CN2017/113193
Authority: WO
Inventors: 宗坚
Original assignee: 江苏菲沃泰纳米科技有限公司
Priority date: 2017-05-21
Filing date: 2017-11-27
Publication date: 2018-11-29
Also published as: CN107201511A; CN107201511B

Abstract

Disclosed is a method for preparing a multi-functional protective nano coating by means of cyclical periodic alternating discharge, which belongs to the technical field of plasma. In the method, a reaction cavity is vacuumized and an inert gas is introduced thereinto; a substrate is made to move in the reaction cavity; monomer vapor is introduced into the reaction cavity; chemical vapor deposition is carried out; the deposition process comprises a preprocessing stage and a film-plating stage, wherein in the preprocessing stage, a plasma discharge mode is high-power continuous discharge, and in the film-plating stage, the plasma discharge mode is periodic alternating discharge; the preprocessing stage and the film-plating stage are cyclically repeated at least once; and during the film-plating process, cyclical introduction is carried out to introduce more active sites on a surface of the substrate, thereby increasing effective film plating, and making a film structure denser. A nano coating of a multi-layered composite structure is obtained, providing multi-layered protection for the product itself. The nano coating exhibits a denser coating structure at the micro level, and exhibits excellent hydrophobicity, adhesion, acid and alkali resistance, mechanical properties, and heat and humidity resistance at the macro level.

Description

Method for preparing multifunctional nano protective coating by cyclically alternating discharge

Technical field

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

Corrosive environments are the most common factor in the destruction of electronic devices. Corrosion of solid materials in electronic devices due to environmental corrosion, reduced conductor/semiconductor insulation, and short-circuit, open circuit, or poor contact. 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, mildew and corrosion resistance of electronic products are becoming more and more strict. In the field of communication, with the continuous advancement of technology, the communication frequency is constantly increasing, and the requirements for the heat dissipation of communication equipment and the stability and reliability of signal transmission are also increasing. Therefore, a reliable method is needed to effectively protect the circuit board and electronic components without affecting normal heat dissipation and signal transmission.

Polymer coatings are often used for material surface protection due to their economical, easy-to-coat and wide application range, which can give materials good physical and chemical durability. Based on the barrier properties of polymer coatings, the protective film formed on the surface of electronic appliances and circuit boards can effectively isolate the circuit board, and protect the circuit from corrosion and damage in a corrosive environment, thereby improving the reliability of the electronic device. Increased safety factor and guaranteed service life are used as anti-corrosion coatings.

Conformal coating is a process of applying a specific material to a PCB to form an insulating protective layer conforming to the shape of the object to be coated. It is a commonly used circuit board waterproofing method, which can effectively isolate the circuit board. And protect the circuit from the erosion and damage of harsh environments. At present, there are some problems and drawbacks in the preparation process of the conformal coating: the solvent in the liquid phase method is easy to damage the circuit board device. Injury; heat-cured coatings tend to cause damage to the device at high temperatures; photocurable coatings are difficult to seal inside the device. Union Carbide Co. developed and applied a new conformal coating material. Parylene coating is a para-xylene polymer with low water, gas permeability and high barrier effect to achieve moisture, water and defense. Rust, acid and alkali corrosion resistance. It has been found that parylene is deposited under vacuum and can be applied to fields that cannot be covered by liquid coatings such as high frequency circuits and extremely weak current systems. The thickness of the polymer film coating is the main reason for the protection failure of the para-xylene vapor-deposited conformal coating. The polymer film coating of the printed circuit board component is prone to local rust failure at a thickness of 3 to 7 microns without affecting the high. The coating thickness should be ≥ 30 μm in the case of frequency dielectric loss. Parylene coating requires high pretreatment of printed circuit boards that need protection, such as conductive components, signal transmission components, RF components, etc., in the vapor deposition of conformal coatings, it is necessary to pre-mask the circuit board components to avoid Affects component performance. This drawback has brought great limitations to the application of parylene coating. Pyrene coatings have high cost of raw materials, harsh coating preparation conditions (high temperature, high vacuum requirements), low film formation rate, and are difficult to be widely used. In addition, thick coatings are prone to problems such as poor heat dissipation, signal blocking, and increased coating defects.

Plasma chemical vapor deposition (PCVD) is a technique in which a reactive gas is activated by a plasma to promote a chemical reaction on a surface of a substrate or a near surface to form a solid film. Plasma chemical vapor deposition coatings have the following advantages:

(1) It is a dry process that produces a uniform film without pinholes.

(2) The plasma polymerization film is stable in chemical and physical properties such as solvent resistance, chemical corrosion resistance, heat resistance, and abrasion resistance.

(3) The plasma polymerization film has good adhesion to the substrate.

(4) A uniform film can also be formed on the surface of the substrate having irregular irregularities.

(5) The coating preparation temperature is low, and can be carried out under normal temperature conditions, thereby effectively avoiding damage to temperature sensitive devices.

(6) The plasma process can not only prepare a coating having a thickness of a micron order but also can prepare an ultra-thin nano-scale coating.

P2i UK 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, based on a specific small duty cycle pulse discharge. The preparation process of the method cannot achieve 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 material, and the scratch resistance and durability of the prepared coating are not satisfactory. It is precisely because of the performance limitation of the coating that the coating can only form a liquid-repellent 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 the specific small duty cycle pulse discharge method has a fatal disadvantage: from a microscopic point of view, the smaller power density during the coating process is not conducive to the formation of a dense structure, or even a stable film. Structure; macroscopically, a smaller power density is not conducive to a large rate of growth of the coating, and its effectiveness in actual production is low, which limits its application.

In the preparation process of the existing plasma chemical vapor deposition coating, the substrate is fixed, and the motion state of the substrate is not related to the discharge energy of the plasma; the stationary substrate is treated by the continuous discharge method. The activated chain scission in the monomer is generally formed into a film by simple stacking under the action of continuous discharge, and the obtained plating layer generally has a loose structure and even a high degree of pulverization, which is disadvantageous to the formation of a microscopic dense structure of the coating layer. Waterproof, moisture-proof, corrosion-resistant, solvent-resistant and other protective properties are poor.

Due to the different regional differences in plasma density and chemical material density in the reaction chamber, the stationary state of the substrate may result in slow deposition of coatings in some regions, low production efficiency, and a large difference in uniformity and compactness.

Summary of the invention

The present invention provides a method for preparing a multifunctional nano-protective coating by cyclically alternating discharge in order to solve the above technical problems. In the preparation process, the process mainly includes pretreatment and coating stages, and the pretreatment stage The segment plasma discharge mode is a high-power continuous discharge, and the plasma discharge mode in the coating phase is periodic alternating discharge, and the pretreatment and coating process are repeated at least twice to form a multilayer dense structure. And the combination of the motion characteristics of the substrate and the plasma discharge energy, while the plasma discharge energy is output, the substrate remains in motion. Additional monomeric components with a polyfunctional crosslinked structure are introduced by plasma energy to introduce additional crosslinking sites to form a crosslinked structure. The plasma discharge generates a plasma, and by controlling the relationship between the plasma discharge energy and the bond energy of the monomer, the effective activation of the higher energy active group in the monomer component by the low temperature plasma is obtained, and at the same time, The additional active sites introduced are cross-linked and polymerized in a plasma environment to form a dense network structure.

The technical solutions adopted by the present invention are as follows:

A method for preparing a multifunctional nano-protective coating by cyclically alternating discharge, comprising: the following steps:

(1) placing the substrate in a reaction chamber of the nano-coating preparation device, continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 to 200 mTorr, and introducing an inert gas of He or Ar. Opening the motion mechanism to cause the substrate to move in the reaction chamber;

(2) introducing monomer vapor into the reaction chamber to a vacuum of 30 to 300 mTorr, opening a plasma discharge, and performing chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 120-400 W, the continuous discharge time is 60-450 s, and then enters the coating stage. The plasma in the coating stage is the periodic alternating discharge output, and the power is 50. ~200W, time 600s ~ 3600s, the frequency conversion rate is 1-1000Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) at least once, and preparing a multifunctional nano-coating by chemical vapor deposition on the surface of the substrate;

The purpose of the pretreatment stage is to activate the surface of the substrate to form numerous active sites on the surface of the substrate. The The bombardment pretreatment can clean the surface of the substrate and activate the surface of the substrate, which facilitates the deposition of the coating and improves the adhesion of the coating to the substrate. The high-power pretreatment bombardment process can further form a plurality of active sites on the surface of the membrane layer, activating the surface of the membrane layer, facilitating further deposition of the coating layer, increasing the bonding force between the membrane layers, forming a high binding force and a high density. The multi-layer coating structure, compared with the general single-time long-time coating, the bonding strength and the density are increased by at least 20%-40% and 15%-30%, respectively, and the method of alternately placing the plating film in the cycle is effective and practical. Stronger.

The monomer vapor component is:

a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, wherein the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 65%;

(5) Stop the flow of monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber for 10~200 mTorr for 1~5 min, then pass into the atmosphere to an atmospheric pressure to stop the movement of the substrate, then Take out the substrate.

In the pretreatment stage, the plasma discharge form is a continuous discharge with a high power of 120-400W. The plasma discharge form in the coating stage is periodic alternating discharge, the power is 50-200W, the time is 600s-3600s, the frequency conversion rate is 1-1000Hz, the plasma discharge The plasma generated by the deposition process has a certain etching on the deposited film; alternating periodic discharge during the coating phase combined with the substrate motion characteristics is beneficial to accelerate the speed of chemical deposition, compared with the existing small duty cycle pulse discharge technology. The continuous discharge method has a thicker and denser film thickness and higher coating efficiency, thus solving the fatality of the dense protective coating prepared by the British P2i company based on the specific small duty cycle pulse discharge method mentioned in the background art. Disadvantages.

In the low-vacuum plasma discharge environment, by controlling the effective output of energy, the chemical bonds in the more active monomer are controlled to break, forming higher-activity free radicals, excited-state free radicals and The surface activating groups of mobile phones and the like initiate polymerization to form a nanometer waterproof film by chemical bonding, and form a multifunctional nano-coating on the surface of the substrate.

In the step (1), the substrate generates motion in the reaction chamber, and the substrate moves in the form of a linear reciprocating motion or a curved motion of the substrate relative to the reaction chamber, the curved motion including circular motion, elliptical motion, planetary motion, Curved motion of spherical motion or other irregular routes.

The substrate in the step (1) is a solid material, and the solid material is an electronic product, an electrical component, an electronic assembly semi-finished product, a PCB board, a metal plate, a polytetrafluoroethylene plate or an electronic component, and the surface of the substrate After preparing the multifunctional nano-coating, any interface can be exposed to water environment, mold environment, acid, alkaline solvent environment, acid, alkaline salt spray environment, acidic atmospheric environment, organic solvent soaking environment, cosmetic environment, sweat environment , use in hot and cold cycle impact environment or wet heat alternating environment.

The volume of the reaction chamber in the step (1) is 50 to 1000 L, the temperature of the reaction chamber is controlled at 30 to 60 ° C, and the flow rate of the inert gas is 5 to 300 sccm.

The reaction chamber is a rotating body chamber or a cubic chamber.

The monomer steam is introduced into the reaction chamber by atomizing, volatilizing and introducing the monomer into the reaction chamber by a low pressure of 10 to 200 mTorr, and the flow rate of the monomer is 10 to 1000 μL/min;

The monofunctional unsaturated fluorocarbon resin includes:

3-(Perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorohexyl)ethyl methacrylate Ester, 2-(perfluorododecyl)ethyl acrylate, 2-perfluorooctyl acrylate, 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 2-(perfluorobutyl) Ethyl acrylate, (2H-perfluoropropyl)-2-acrylate, (perfluorocyclohexyl)methacrylate, 3,3,3-trifluoro-1-propyne, 1-ethynyl-3 , 5-difluorobenzene or 4-ethynyl trifluorotoluene;

The polyfunctional unsaturated hydrocarbon derivative includes:

Ethoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, polyethylene glycol Diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol divinyl ether or neopentyl glycol diacrylate.

In the steps (3) and (4), the plasma discharge mode is radio frequency discharge, microwave discharge, intermediate frequency discharge, high frequency discharge, and electric spark discharge, and the waveforms of the high frequency discharge and the intermediate frequency discharge are sinusoidal or bipolar pulses. The radio frequency plasma is a plasma generated by discharging a high-frequency electromagnetic field. The microwave method utilizes the energy of the microwave to excite the plasma, and has the advantages of high energy utilization efficiency. At the same time, since the electrodeless discharge and the plasma are pure, it is an excellent method for high-quality, high-rate, large-area preparation.

In the steps (3) and (4), the plasma cycle alternately changes the discharge output waveform to a sawtooth waveform, a sinusoidal waveform, a square wave waveform or a chirp waveform.

During the preparation of the coating, the motion characteristics of the substrate and the plasma discharge energy are combined. During the plasma discharge during the preparation process, the substrate generates motion, improves the deposition efficiency of the coating, and improves the uniformity and compactness of the coating thickness.

The prepared coating has waterproof, moisture proof, mold proof, acid resistance, alkaline solvent, acid resistance, alkaline salt spray, acid resistance atmosphere, organic solvent immersion resistance, cosmetics resistance, sweat resistance, cold and heat cycle impact resistance (-40 ° C ~ +75 ° C), resistance to heat and humidity (humidity 75% to 95%) and other characteristics. With the above protective performance, the coating thickness is between 1 and 1000 nm, and the influence on the RF communication signal in the range of 10M to 8G is less than 5%.

The above technical solution of the present invention has the following advantages compared with the prior art:

1. The cyclic coating introduces a high-power pretreatment activation stage in the process stage. The cycle introduction is beneficial to introduce more active sites on the surface of the substrate at this stage, increase the effective coating, and the film structure is more compact. Corrosive environments provide better protection. In the coating process, the nano-coating of the multi-layer composite structure is obtained by the cyclic coating process, which provides multi-layer protection for the product itself, and the microscopically presents a denser coating structure, which is excellent in macroscopic performance. Hydrophobicity, adhesion, acid and alkali resistance, Mechanical properties and resistance to heat and humidity.

2. During the cyclic coating process, a periodic alternating discharge is introduced in the coating stage, and a plasma capable of generating sufficient energy interrupts the incoming monomer segment to form more excited-state segments, and the excited state chain The end of the monomer material in the monomer material with a certain energy, active active site and the corresponding energy of the substrate surface in the form of chemical bonds will produce more and more complex elementary reactions, forming a more dense network cross-linking structure;

3. Pretreatment and coating stage, the substrate moves in the reaction chamber, so that the coating thickness of the substrate at different positions tends to be uniform, which solves the uneven thickness of the coating on the surface of the substrate due to the different monomer density in different regions of the reaction chamber. problem.

4. During the preparation process, the combination of the motion characteristics of the substrate and the plasma discharge energy, while the discharge energy is output, the substrate is moved, the deposition efficiency is improved, and the compactness of the multifunctional nano-protective coating is significantly improved. At the same time, due to the increase of deposition efficiency, the amount of chemical monomer raw materials used in monomer steam is only 10% to 15% of the amount in other prior art, thereby reducing emissions of exhaust gas, making it more environmentally friendly and improving actual production efficiency. It has great significance.

5. The introduction of the cross-linking structure of the polyfunctional group in the monomer material promotes the formation of the dense network structure of the coating on the microstructure, and improves the acid/alkali corrosion resistance of the coating to the environment while ensuring the hydrophobicity.

In general, plasma polymerization uses a monofunctional monomer to obtain a coating having a certain crosslinked structure. The crosslinked structure is formed by a plurality of active sites formed by chain scission of a monomer during plasma discharge by cross-linking. However, this crosslinked structure is relatively loose, contains more linear components, and is resistant to solution penetration and solubility. The present invention introduces additional crosslinking points by introducing other monomer components with a polyfunctional crosslinked structure to form a crosslinked structure. During plasma discharge, under the action of low temperature plasma, the active group with higher energy in the monomer component is broken to form an active point by effective control and output of energy, and the additional active point introduced is in the plasma environment. Cross-linking and polymerizing to form a dense network structure.

Compared with the coating structure with loose linear components, the mesh structure has better compactness and can effectively improve the corrosion-resistant environment of the film. In the plasma environment, the surface of the coated substrate is activated to obtain a plurality of active sites. The active sites are combined with the active radicals of the plasma-excited monomeric material with strong chemical bonds, and various forms of primitives are generated. The reaction makes the nano film of the base material have excellent bonding force and mechanical strength. By controlling the mixing mode of different monomers and controlling different process conditions at the same time, the effective control of the corrosion-resistant environment of the material surface is realized, and the structure with large roughness of the underlying dense surface layer with special microstructure is obtained, and the comprehensive performance of environmental corrosion resistance is obtained. Increased by 25% to 45%.

6. By introducing other monomers of cross-linking structure, controlling the monomer ratio, according to the difference of molecular bond energy, bond length and vaporization temperature of different monomers, the corresponding energy output and effective changes of process parameters are given to the device. The composite nano-coating with a composite structure and a gradual structure not only ensures the hydrophobicity of the film, but also improves the environmental corrosion resistance of products such as electronic products.

Electronic equipment in daily life is extremely vulnerable to corrosion by corrosive environments, and is basically in a corrosive environment during use. In the long run, it will cause irreparable damage to electronic equipment. The coating method of the patent of the invention greatly increases the significance of the nanometer in improving the actual production efficiency. The service life of the coating in a corrosive environment increases the protection of the product. Mainly used in the following products:

(1), portable device keyboard: portable keyboard has small and light features, commonly used in computers, mobile phones and other equipment. It makes it easy for users to work on the journey. However, when it encounters the contamination of common liquids, such as the accidental overturn of the water cup, the soaking of rain and sweat, the inside of the keyboard is easily short-circuited and damaged. After coating with this type of nano-coating, it can ensure that the surface of the keyboard is easy to clean and function properly after being exposed to water, so that the keyboard can adapt to a more severe environment.

(2), LED display: LED display has product promotion, store decoration, lighting, warning, etc. way. Some of its uses need to face the harsh environment of rain or dust, such as the rainy days, the mall's open-air LED advertising screen, road warning lights, LED display control panel in the production workshop, these harsh environments lead to LED screen failure, and easy to accumulate dust, It is difficult to clean, and after using the nano-coating, the above problems can be effectively solved.

(3), intelligent fingerprint lock: fingerprint lock is a smart lock, which integrates computer information technology, electronic technology, mechanical technology and modern hardware technology, is widely used in public security criminal investigation and judicial field. However, after it meets water, its internal circuit is short-circuited, difficult to repair, and requires violent de-locking. This coating can be used to avoid this problem.

(4), hearing aid, Bluetooth headset: There is no communication line between the hearing aid and the Bluetooth headset. After using this coating, the user can use it in a water environment for a certain period of time, such as bathing, raining, the equipment will not be infiltrated by rain. damage.

(5) Some sensors: Some sensors need to work in a liquid environment, such as water pressure, oil pressure sensors, and sensors used in underwater operation equipment, as well as sensors that often encounter water in the working environment. These sensors use this coating. After the layer, it can guarantee that the sensor will not malfunction due to the liquid invading the internal structure of the mechanical device.

(6) Most 3C products: such as mobile phones, notebooks, PSPs, etc.

(7) Other equipment that needs to be waterproof: including equipment that needs to work in a humid environment, or may encounter unexpected accidents such as liquid spills, which may affect the normal operation of internal weak current lines.

The multifunctional nano-coating prepared by the method can also be applied to the following different environments and related products involved:

Waterproof, moisture proof, moldproof:

1 House interior: bathroom top, wallpaper, chandeliers, curtains, screens. 2 daily necessities: mosquito nets, table lamp covers, chopsticks, car rearview mirrors. 3 artifacts and works of art: copybook, antiques, woodcarving, leather, blue Bronze, silk, costumes, ancient books. 4 Electronic components and electronic products: sensors (working in wet or dusty environments), chips of various electronic products (electronic sphygmomanometers, smart watches), circuit boards, mobile phones, LED screens, hearing aids. 5 precision instruments and optical equipment: mechanical watches, microscopes.

Acid and alkaline solvents, acid and alkali salt spray, acid resistant atmosphere:

1 housing interior parts: wallpaper, tiles. 2 protective equipment: acid (alkali) gloves, acid (alkali) protective clothing. 3 Mechanical equipment and pipelines: flue desulfurization equipment, seals (acid/alkaline lubricants), pipes, valves, large-diameter sea pipelines, etc. 4 various reactors, reactors. 5 chemical production, storage; sewage treatment, aeration tank; 6 other: acid and alkali workshop, anti-alkali aerospace, energy and power, steel and metallurgy, petrochemical, medical and other industries, storage containers, statues (reduced acid rain Corrosion), sensor (acid/alkaline environment).

Soaked with organic solvents, resistant to cosmetics, sweat resistant:

1 such as paraffin, olefin, alcohol, aldehyde, amine, ester, ether, ketone, aromatic hydrocarbon, hydrogenated hydrocarbon, terpene olefin, halogenated hydrocarbon, heterocyclic compound, nitrogen-containing compound and sulfur compound solvent; 2 cosmetic packaging container ; 3 fingerprint lock, headphones.

Resistance to cold and heat cycle (-40 ° C ~ +75 ° C), resistance to heat and humidity (humidity 75% ~ 95%): electrical, electronic, automotive electrical, such as aviation, automotive, home appliances, scientific research and other fields of equipment.

detailed description

The invention is described in detail below with reference to the drawings and specific embodiments, but the invention is not limited to the specific embodiments.

Example 1

A method for preparing a multifunctional nano-protective coating by cyclically alternating discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 mTorr, and introducing an inert gas Ar, Open a moving mechanism that causes the substrate to move within the reaction chamber;

The substrate in the step (1) is a solid material, the solid material is a bulk aluminum material and a PCB board, and the surface of the substrate is prepared to be exposed to cold and heat after being subjected to a cold and heat resistant cyclic impact coating. In a loop test environment.

The volume of the reaction chamber in the step (1) was 50 L, the temperature of the reaction chamber was controlled at 30 ° C, and the flow rate of the inert gas was 5 sccm.

In the step (1), the substrate moves in the reaction chamber, and the substrate moves in the form of a circular motion of the substrate relative to the reaction chamber at a rotation speed of 6 rpm.

(2) introducing monomer vapor into the reaction chamber, and when the degree of vacuum is 30 mTorr, plasma discharge is turned on to perform chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 400W, the continuous discharge time is 60s, and then enters the coating stage. The plasma in the coating stage is the alternating discharge output of the cycle, the power is 200W, and the time is 600s. The frequency conversion rate is 1 Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) 10 times, preparing a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

Passing monomer steam to atomize and volatilize the monomer through the feed pump, and introduce the reaction chamber into the reaction chamber by a low pressure of 10 mTorr, and the flow rate of the monomer vapor is 1000 μL/min;

The monomer vapor composition is:

a mixture of two monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15%;

The monofunctional unsaturated fluorocarbon resin is: 2-perfluorooctyl acrylate ethyl ester, 2-(perfluorohexyl) ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivative is: ethylene glycol diacrylate, 1,6-hexanediol diacrylate;

In the step (3) and the step (4), the plasma cycle alternately changes the discharge output waveform to a sawtooth waveform. The plasma discharge mode is radio frequency discharge.

(5) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 10 mTorr, and then open the atmosphere to an atmospheric pressure after 1 min, then take out the substrate. .

The obtained test results of the coated aluminum material and PCB board are as follows:

(1) Thermal and thermal cycle impact test results:

(2) Damp heat alternation test results:

Example 2

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 60 mTorr, and introducing an inert gas He to start a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, and the solid material is a bulk aluminum material, and any interface of the surface of the substrate after the preparation of the moisture-resistant heat alternating coating can be exposed to the damp heat test environment.

The volume of the reaction chamber in the step (1) was 250 L, the temperature of the reaction chamber was controlled at 40 ° C, and the flow rate of the inert gas was 15 sccm.

In the step (1), the substrate is subjected to planetary motion, the revolution speed is 6 rpm, and the rotation speed is 3 rpm.

(2) introducing monomer vapor into the reaction chamber, and when the degree of vacuum is 90 mTorr, plasma discharge is turned on to perform chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 120W, the continuous discharge time is 450s, and then enters the coating stage. The plasma in the coating stage is the alternating discharge output of the cycle, the power is 50W, and the time is 3600s. The frequency conversion rate is 1000 Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) one time, preparing a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer through a feed pump, and the flow rate of the monomer vapor is 500 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 28%;

The monofunctional unsaturated fluorocarbon resin is: 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorododecyl)ethyl acrylate, (perfluorocyclohexyl)methyl Acrylate;

The polyfunctional unsaturated hydrocarbon derivative is: tripropylene glycol diacrylate and polyethylene glycol diacrylate;

In the step (3) and the step (4), the plasma cycle is alternately changed, and the discharge output waveform is a square wave waveform. The plasma discharge mode is microwave discharge.

(5) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 80 mTorr, and then open the atmosphere to an atmospheric pressure after 2 min, then take out the substrate. .

The performance test results of the obtained aluminum material after coating are as follows:

(1) Thermal and thermal cycle impact test results:

(2) Damp heat alternation test results:

Example 3

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 130 mTorr, and introducing an inert gas Ar to start. a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, the solid material is a bulk polytetrafluoroethylene plate and an electrical component, and any interface of the block-shaped polytetrafluoroethylene plate is exposed after the preparation of the anti-fungal coating. Used in the GJB150.10A-2009 mold test environment, the surface of the electrical component can be exposed to the environment described in the international industrial waterproof rating standard IPX7 after the waterproof and electrical breakdown coating is prepared.

The volume of the reaction chamber in the step (1) was 480 L, the temperature of the reaction chamber was controlled at 50 ° C, and the flow rate of the inert gas was 50 sccm.

In the step (1), the substrate was subjected to a circular motion at a rotation speed of 6 rpm.

(2) introducing monomer vapor into the reaction chamber, and when the degree of vacuum is 150 mTorr, plasma discharge is turned on to perform chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 200W, the continuous discharge time is 150s, and then enters the coating stage. The plasma in the coating stage is the periodic alternating discharge output, the power is 160W, and the time is 1000s. The frequency conversion rate is 780Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) six times, preparing a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer through a feed pump, and the flow rate of the monomer vapor is 550 μL/min;

The monomer vapor composition is:

a mixture of two monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 45%;

The monofunctional unsaturated fluorocarbon resin is: (perfluorocyclohexyl) methacrylate and 2-(perfluorohexyl)ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivative is: ethoxylated trimethylolpropane triacrylate and diethylene glycol divinyl ether;

In step (3) and step (4), the plasma cycle alternates and the discharge output waveform is a sinusoidal waveform. The plasma discharge mode is a medium frequency discharge, and a waveform bipolar pulse of an intermediate frequency discharge.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 130 mTorr, and then open the atmosphere to an atmospheric pressure after 3 minutes, then take out the substrate. .

After the above PTFE plate coating, GJB150.10A-2009 mold test results:

The above-mentioned electrical components were tested for underwater soaking test results at different voltages after preparation of the coating:

IPX 7 waterproof rating test (underwater 1m water immersion test 30min) results:

Example 4

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 160 mTorr, and introducing an inert gas He to start a moving mechanism that moves the substrate;

The volume of the reaction chamber in the step (1) was 680 L, the temperature of the reaction chamber was controlled at 50 ° C, and the flow rate of the inert gas was 160 sccm.

In the step (1), the substrate is linearly reciprocated at a moving speed of 30 mm/min.

(2) introducing monomer vapor into the reaction chamber, and when the degree of vacuum is 190 mTorr, plasma discharge is turned on to perform chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 300W, the continuous discharge time is 250s, and then enters the coating stage. The plasma in the coating stage is the alternating discharge output of the cycle, the power is 120W, and the time is 2000s. The frequency conversion rate is 600 Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) three times, preparing a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer, and is introduced into the reaction chamber by a low pressure of 160 mTorr, and the flow rate of the monomer vapor is 220 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and three polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 47%;

The monofunctional unsaturated fluorocarbon resin is: 3,3,3-trifluoro-1-propyne, 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 1H , 1H, 2H, 2H-perfluorooctyl acrylate;

The polyfunctional unsaturated hydrocarbon derivatives are: ethoxylated trimethylolpropane triacrylate, ethylene glycol diacrylate and 1,6-hexanediol diacrylate;

In the step (3) and the step (4), the plasma cycle is alternately changed, and the discharge output waveform is a skull-shaped waveform. The plasma discharge mode is high frequency discharge, and the high frequency discharge is sinusoidal.

(5) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 160 mTorr, and then open the atmosphere to an atmospheric pressure after 4 minutes, then take out the substrate. .

After the above PTFE plate coating, GJB150.10A-2009 mold test results:

Example 5

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 200 mTorr, and introducing an inert gas Ar to start. a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, and the solid material is a bulk aluminum material, and any interface of the substrate surface can be exposed to an acid or alkali test environment after preparing an acid-proof and alkaline environment coating. .

The volume of the reaction chamber in the step (1) was 1000 L, the temperature of the reaction chamber was controlled at 60 ° C, and the flow rate of the inert gas was 300 sccm.

In step (1), the substrate undergoes planetary motion, the planetary revolution speed is 4 rpm, and the planetary rotation speed is 2 rpm.

(2) introducing monomer vapor into the reaction chamber, and when the degree of vacuum is 300 mTorr, plasma discharge is turned on to perform chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 150W, the continuous discharge time is 400s, and then enters the coating stage. The plasma in the coating stage is the alternating discharge output of the cycle, the power is 100W, and the time is 3000s. The frequency conversion rate is 300 Hz;

(4) Repeating the pretreatment stage and the coating stage twice in the step (3), chemistry on the surface of the substrate Preparation of multifunctional nano-coating by vapor deposition;

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer through a feed pump, and the flow rate of the monomer vapor is 10 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 65%;

The monofunctional unsaturated fluorocarbon resin is: 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 3,3,3-trifluoro-1-propyne and 2-(perfluorohexyl)ethyl Methacrylate

The polyfunctional unsaturated hydrocarbon derivative is: tripropylene glycol diacrylate and ethylene glycol diacrylate;

In the step (3) and the step (4), the plasma cycle alternately changes the discharge output waveform to a square waveform. The plasma discharge mode is an electric spark discharge.

(5) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 200 mTorr, and then open the atmosphere to an atmospheric pressure after 5 min, then take out the substrate. .

The test results of the above-mentioned aluminum material after coating are as follows:

(1) Hydrophobic oleophobic performance

(2) Organic solvent resistance test results: (pass means that the contact angle changes less than 5° after immersion for a period of time)

(3) Acid and alkaline test results: (pass indicates that corrosion does not occur after a period of time)

Claims

A method for preparing a multifunctional nano-protective coating by cyclically alternating discharge, comprising: the following steps:

(1) placing the substrate in a reaction chamber of the nano-coating preparation device, continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 to 200 mTorr, and introducing an inert gas of He or Ar. Opening the motion mechanism to cause the substrate to move in the reaction chamber;

(2) introducing monomer vapor into the reaction chamber to a vacuum of 30 to 300 mTorr, opening a plasma discharge, and performing chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. The plasma discharge power of the pretreatment stage is 120-400 W, the continuous discharge time is 60-450 s, and then enters the coating stage. The plasma in the coating stage is the periodic alternating discharge output, and the power is 50. ~200W, time 600s ~ 3600s, the frequency conversion rate is 1-1000Hz;

(4) repeating the pretreatment stage and the coating stage in the step (3) at least once, and preparing a multifunctional nano-coating by chemical vapor deposition on the surface of the substrate;

The monomer vapor component is:

a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, wherein the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 65%;

(5) Stop the flow of monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber for 10~200 mTorr for 1~5 min, then pass into the atmosphere to an atmospheric pressure to stop the movement of the substrate, then Take out the substrate.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein in the step (1), the substrate generates motion in the reaction chamber, and the substrate movement form is a base. The material is linearly reciprocated or curved with respect to the reaction chamber, and the curved motion package Curved motion including circular motion, elliptical circumferential motion, planetary motion, spherical motion, or other irregular routes.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein the substrate in the step (1) is a solid material, and the solid material is an electronic product or an electric appliance. Components, electronic assembly semi-finished products, PCB boards, metal sheets, Teflon sheets or electronic components, and any interface of the substrate surface can be exposed to water environment, mold environment, acid after preparing multifunctional nano-coating , alkaline solvent environment, acid, alkaline salt spray environment, acidic atmospheric environment, organic solvent soaking environment, cosmetic environment, sweat environment, cold and heat cycle impact environment or wet heat alternating environment.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein the volume of the reaction chamber in the step (1) is 50 to 1000 L, and the temperature of the reaction chamber The control is carried out at 30 to 60 ° C, and the flow rate of the inert gas is 5 to 300 sccm.
The method according to claim 1 or 4, wherein the reaction chamber is a rotating body chamber or a cubic chamber.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein in the step (2): introducing a monomer vapor into the mist by passing the monomer through a feeding pump The solution is volatilized and introduced into the reaction chamber from a low pressure of 10 to 200 mTorr, and the flow rate of the monomer is 10 to 1000 μL/min.
A method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein:

The monofunctional unsaturated fluorocarbon resin includes:

3-(Perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorohexyl)ethyl methacrylate Ester, 2-(perfluorododecyl)ethyl acrylate, 2-perfluorooctyl acrylate, 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 2-(perfluorobutyl) Ethyl acrylate, (2H-perfluoropropyl)-2-acrylate, (perfluorocyclohexyl)methacrylate, 3,3,3-trifluoro-1-propyne, 1-ethynyl-3,5-difluoro Benzene or 4-ethynyl trifluorotoluene;

The polyfunctional unsaturated hydrocarbon derivative includes:

Ethoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol Alcohol divinyl ether or neopentyl glycol diacrylate.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein in the steps (3) and (4), the plasma discharge mode is radio frequency discharge and microwave discharge , medium frequency discharge, high frequency discharge, electric spark discharge, the waveform of the high frequency discharge and the intermediate frequency discharge is a sinusoidal or bipolar pulse.
The method for preparing a multifunctional nano-protective coating by cyclic cycle alternating discharge according to claim 1, wherein in the step (3) and the step (4), the plasma cycle is alternately changed, and the discharge output waveform is sawtooth Waveform, sinusoidal waveform, square wave waveform, or skull waveform.