CN107142465B - A method of cycle small-power continuous discharge prepares multi-functional nano protecting coating - Google Patents

Abstract

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge belongs to the field of plasma technology. Movement, feed the monomer vapor into the reaction chamber, and carry out chemical vapor deposition. The deposition includes the pretreatment stage and the coating stage. The plasma discharge method in the pretreatment stage is high-power continuous discharge, and the plasma discharge method in the coating stage is low-power continuous discharge. , cyclically repeat the pretreatment stage and the coating stage at least once. During the coating process, the cyclic introduction can introduce more active sites on the surface of the substrate, increase the effective coating, make the film structure denser, and obtain a nano-coating with a multilayer composite structure , provides multi-layer protection for the product itself, microscopically shows a denser coating structure, and macroscopically shows excellent hydrophobicity, adhesion, acid and alkali resistance, mechanical properties and heat and humidity resistance.

Description

A method for preparing multifunctional nano-protective coating by cyclic low-power continuous 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 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, and the requirements for the stability and reliability of signal transmission are also getting higher and higher. Therefore, there is a need for a reliable method that can effectively protect the circuit board and electronic components without affecting normal heat dissipation and signal transmission.

Polymer coatings are often used for the protection of material surfaces due to their economical, easy-to-coat, and wide-ranging applications, which can endow materials with 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 circuit boards and protect circuits from erosion and damage in corrosive environments, thereby improving the reliability of electronic devices. To increase its safety factor and ensure its service life, it is used as an anti-corrosion coating.

Conformal coating is a process of coating a specific material on a PCB to form an insulating protective layer that is consistent with the shape of the coated object. It is a commonly used waterproof method for circuit boards, which can effectively isolate circuit boards. , and can protect the circuit from erosion and damage in harsh environments. There are also some problems and disadvantages in the current preparation process of conformal coatings: the solvent in the liquid phase method is easy to cause damage to the circuit board device; the high temperature of the thermal curing coating is easy to cause damage to the device; it is difficult for the light curing coating to be sealed inside the device . Union Carbide Co. of the United States has developed and applied a new type of conformal coating material. Parylene coating is a polymer of p-xylene, which has low water and gas permeability and high barrier effect to achieve moisture-proof, waterproof and anti-corrosion. Rust, anti-acid and alkali corrosion. Studies have found that parylene is deposited in a vacuum state and can be used in areas where liquid coatings cannot be involved, such as the protection of high-frequency circuits and extremely weak current systems. The thickness of the polymer film coating is the main reason affecting the failure of the parylene vapor deposition conformal coating. The polymer film coating of printed circuit board components is prone to local corrosion failure at a thickness of 3 to 7 microns. In the case of high frequency dielectric loss, the coating thickness should be ≥ 30 microns. Parylene coating has high pretreatment requirements for printed circuit boards that need to be protected, such as conductive components, signal transmission components, radio frequency components, etc. During vapor deposition of conformal coatings, circuit board components need to be shielded and pretreated to avoid impact on component performance. This disadvantage has brought great restrictions to the application of parylene coating. The raw material cost of parylene coating preparation is high, the coating preparation conditions are harsh (high temperature, high vacuum requirements), and the film formation rate is low, so it is difficult to be widely used. In addition, thick coatings can easily lead to problems such as poor heat dissipation, signal blocking, and increased coating defects.

Plasma chemical vapor deposition (PCVD) is a technology that uses plasma to activate reactive gases to promote chemical reactions on the surface of the substrate or in the space near the surface to form a solid film. Plasma chemical vapor deposition coating has the following advantages:

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

(2) The chemical and physical properties of the plasma polymerized film are stable such as solvent resistance, chemical corrosion resistance, heat resistance, and wear resistance.

(3) The adhesion between the plasma polymerized film and the substrate is good.

(4) It can also be made into a uniform film on the substrate surface with extremely irregular unevenness.

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

(6) The plasma process can not only prepare micron-scale coatings but also ultra-thin nano-scale coatings.

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 preparation process based on the specific small duty cycle pulse discharge method cannot achieve chemical The effective coordination and control of the bond length, bond energy, molecular weight of the material and the energy provided by the different groups in the raw materials, 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 resolved. 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 high rate growth of the coating, and its efficiency is low in actual production, which limits its application.

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.

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

Contents of the invention

In order to solve the above technical problems, the present invention provides a method for preparing a multifunctional nano protective coating by continuous discharge with low power in cycles. In the preparation process, the process mainly includes pretreatment and coating stages. The plasma discharge method in the pretreatment stage is high-power continuous discharge, and the plasma discharge method in the coating stage is low-power continuous discharge, and the pretreatment and coating process are repeated at least twice. , forming a multilayer dense structure. And it is linked by the movement characteristics of the substrate and the combination of plasma discharge energy. While the plasma discharge energy is output, the substrate remains in motion. The plasma energy is used to introduce other monomer components with a multifunctional crosslinking structure to introduce additional crosslinking points to form a crosslinking structure. Plasma discharge generates plasma. By controlling the relationship between plasma discharge energy and monomer bond energy, low-temperature plasma can effectively activate active groups with higher energy in monomer components to obtain active sites. At the same time, The introduced additional active sites are cross-linked and polymerized under the plasma environment to form a dense network structure.

The technical scheme adopted in the present invention is as follows:

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, characterized in that it comprises the following steps:

(1) The base material is placed in the reaction chamber of the nano-coating preparation equipment, the reaction chamber is continuously evacuated, the vacuum in the reaction chamber is evacuated to 10-200 millitorr, and the inert gas He or Ar is introduced, Turn on the motion mechanism to make the substrate move in the reaction chamber;

(2) Feed monomer vapor into the reaction chamber until the vacuum degree is 30-300 mTorr, turn on the plasma discharge, and carry out chemical vapor deposition;

(3) The deposition process includes the pretreatment stage and the coating stage. In the pretreatment stage, the plasma discharge power is 120-400W, and the continuous discharge time is 60-450s, and then enters the coating stage. Adjust the plasma discharge power to 10-75W, and the continuous discharge time 600～3600s;

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

The purpose of the pretreatment stage is to activate the substrate surface and form numerous active sites on the substrate surface. The bombardment pretreatment can clean the impurities on the surface of the substrate, and at the same time activate the surface of the substrate, which is beneficial to the deposition of the coating and improves the bonding force between the coating and the substrate. During the repeated pretreatment and coating process, each coating The bombardment process of the final high-power pretreatment can further form many active sites on the surface of the film layer, activate the surface of the film layer, facilitate the further deposition of the coating layer, improve the bonding force between the film layers, and form a higher bonding force and density. High multi-layer coating structure, compared with general single-time long-term coating, its bonding force and density have been increased by at least 20%-40% and 15%-30% respectively. The effect of this cycle low-power coating method is obvious and practical strong sex.

The monomer vapor composition is:

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

(5) Stop feeding the monomer steam, stop the plasma discharge at the same time, continue vacuuming, keep the vacuum degree of the reaction chamber at 10-200 mTorr for 1-5 minutes, then feed the atmosphere to an atmospheric pressure, stop the movement of the substrate, and then Just remove the substrate.

In the pretreatment stage, the plasma discharge form is a continuous discharge with a high power of 120-400W, and in the coating stage, the plasma discharge form is a continuous discharge with a low power of 10-75W. The plasma generated in the process of continuous plasma discharge deposition can etch the deposited film to a certain extent; in the coating stage, the low-power continuous discharge combined with the movement characteristics of the substrate is conducive to accelerating the speed of chemical deposition. Compared with the existing small duty cycle pulse Discharge technology, the continuous discharge method within a certain period of time has a thicker and denser film thickness, and a higher coating efficiency, thus solving the problem of preparation based on the specific small duty cycle pulse discharge method of the British P2i company mentioned in the background technology Achilles heel of dense protective coatings.

In a low-vacuum plasma discharge environment, through the effective output of energy, the chemical bonds in monomers with more active molecular structures are controlled to break, forming free radicals with higher activity, and the free radicals in the excited state and the surface active radicals of mobile phones and other products The group initiates polymerization through chemical bonding to form a nano-waterproof film, and forms a multifunctional nano-coating on the surface of the substrate.

In the step (1), the base material moves in the reaction chamber, and the motion form of the base material is that the base material performs linear reciprocating motion or curvilinear motion relative to the reaction chamber, and the curvilinear motion includes circular motion, elliptical circular motion, planetary motion, Spherical motion or other curved motion of irregular course.

In the step (1), the substrate 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 sheet or an electronic component, and the surface of the substrate is After the multifunctional nano-coating is prepared, any interface can be exposed to water environment, mold environment, acid and alkaline solvent environment, acid and alkaline salt spray environment, acid atmospheric environment, organic solvent immersion environment, cosmetic environment, sweat environment , used in hot and cold cycle shock environment or in humid and hot alternating environment.

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

The reaction chamber is a rotator-shaped chamber or a cube-shaped chamber.

The introduction of monomer vapor is to atomize and volatilize the monomer through the feeding pump and introduce it into the reaction chamber at a low pressure of 10-200 mTorr, and the flow rate of the monomer introduction is 10-1000 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 ethyl acrylate, 1H,1H,2H,2H-perfluorooctyl acrylate, 2-(perfluorobutyl) Ethylacrylate, (2H-perfluoropropyl)-2-acrylate, (perfluorocyclohexyl)methacrylate, 3,3,3-trifluoro-1-propyne, 1-ethynyl-3 , 5-difluorobenzene or 4-ethynyltrifluorotoluene;

The polyfunctional unsaturated hydrocarbon derivatives include:

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 plasma discharge mode in the steps (3) and (4) is radio frequency discharge, microwave discharge, intermediate frequency discharge, high frequency discharge, electric spark discharge, and the waveform of the high frequency discharge and intermediate frequency discharge is sinusoidal or bipolar pulse, RF plasma is a plasma generated by high-frequency electromagnetic field discharge. The microwave method uses microwave energy to excite the plasma, which has the advantages of high energy utilization efficiency, and at the same time, due to the electrodeless discharge, the plasma is pure, and is currently an excellent method for high-quality, high-speed, and large-area preparation.

During the coating preparation process, the motion characteristics of the substrate and the combination of plasma discharge energy are linked. During the preparation process, while the plasma discharges, the base material moves, which improves the coating deposition efficiency, and improves the uniformity and compactness of the coating thickness.

The prepared coating is waterproof, moisture-proof, mildew-proof, acid-resistant, alkaline solvent-resistant, acid-resistant, alkaline salt spray resistant, acid-resistant atmosphere, resistant to immersion in organic solvents, resistant to cosmetics, sweat-resistant, and resistant to cold and heat cycles (-40 ° C ~ +75℃), resistance to humidity and heat (humidity 75% ~ 95%) and other characteristics. While possessing the above protection performance, when the thickness of the coating is 1-1000nm, the impact on radio frequency communication signals with a frequency in the range of 10M-8G is less than 5%.

Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages:

1. Cyclic coating introduces a high-power pretreatment and activation stage in the process. The introduction of circulation at this stage is conducive to introducing more active sites on the surface of the substrate at this stage, increasing the effective coating, and the film structure is denser. Better protection against corrosive environments. In the coating process, the cyclic coating process is adopted to obtain a nano-coating with a multi-layer composite structure, which provides multi-layer protection for the product itself. It shows a denser coating structure microscopically, and shows an excellent coating structure macroscopically. Hydrophobicity, adhesion, acid and alkali resistance, mechanical properties and heat and humidity resistance.

2. In the cyclic coating process, continuous low-power discharge is introduced in the coating stage. During the continuous discharge process, two processes of polymerization and etching will occur simultaneously. One is that the excited molecular chain ends interrupted by the plasma pass through chemical bonds. The second is that the plasma will simultaneously etch the molecular chains with low chemical bond energy on the surface after polymerization, and at the same time play a role in activation. The alternating effect of the two makes the polymerized nano-coating denser.

3. In the 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 consistent, which solves the problem of uneven coating thickness on the surface of the substrate due to different monomer densities in different regions of the reaction chamber. question.

4. During the preparation process, the movement characteristics of the substrate are combined with the plasma discharge energy. While the discharge energy is output, the substrate moves, which improves the deposition efficiency and significantly improves the compactness of the obtained multifunctional nano protective coating. At the same time, due to the improvement of deposition efficiency, the amount of chemical monomer raw materials used in monomer steam is only 10% to 15% of the amount used in other existing technologies, thereby reducing exhaust gas emissions, making it more environmentally friendly and improving actual production efficiency. of great significance.

5. The introduction of multifunctional crosslinking structure in the monomer material promotes the formation of a dense network structure of the coating on the microstructure, and improves the acid/alkali corrosion resistance of the coating to the environment while ensuring hydrophobicity.

Generally, monofunctional monomers are selected for plasma polymerization to obtain a coating with a certain cross-linked structure. The cross-linked structure is due to the fact that many active points formed by monomer chain scission during plasma discharge form a cross-linked structure through cross-linking. However, this cross-linked structure is relatively loose, contains more linear components, and has poor solution penetration resistance and solubility. The present invention introduces additional crosslinking points to form a crosslinking structure by introducing other monomer components with multifunctional crosslinking structures. During plasma discharge, under the action of low-temperature plasma, through the effective control and output of energy, the active groups with higher energy in the monomer components are interrupted to form active points, and the additional active points introduced are in the plasma environment. Mutual cross-linking and polymerization to form a dense network structure.

Compared with the coating structure with more loose linear components, the network structure has better compactness, which can effectively improve the anti-corrosion environment performance of the film. In the plasma environment, the surface of the coating base material is activated to obtain many active sites, and these active sites combine with the active free radicals of the monomer materials excited by the plasma with strong chemical bonds, forming various forms and types of primitives. The reaction makes the nano-film of the matrix material have excellent bonding force and mechanical strength. By controlling the combination of different monomers and adjusting different process conditions at the same time, the anti-corrosion environment of the material surface can be effectively adjusted to obtain a structure with a special microstructure, a dense bottom layer and a large surface roughness, and its comprehensive performance of environmental corrosion resistance Increased by 25% to 45%.

6. By introducing other monomers with a cross-linked structure, the ratio of monomers is controlled, and according to the differences in molecular bond energy, bond length, and vaporization temperature of different monomers, the equipment is given corresponding energy output and effective changes in process parameters. Obtaining a polymer nano-coating with a composite and gradient structure not only ensures the hydrophobicity of the film, but also improves the environmental corrosion resistance of electronic products and other products.

Electronic equipment in daily life is extremely vulnerable to corrosion and damage from corrosive environments. During use, it is basically in a corrosive environment. If things go on like this, it will cause irreparable damage to electronic equipment. The coating method of the patent of the present invention has greatly increased the nanometer and has great significance in improving the actual production efficiency. The service life of the coating in the corrosive environment improves the protection effect of the product. Mainly used in the following products:

(1) Portable device keyboards: Portable keyboards are small and light, and are often used in computers, mobile phones and other devices. It can facilitate users to work while traveling. However, when it encounters the pollution of common liquids, such as the accidental overturning of a tea cup filled with water, the soaking of rainwater and sweat, the inside of the keyboard is easily short-circuited, and then damaged. After coating it with this kind of nano-coating, it can ensure that the surface of the keyboard is easy to clean, and the function is intact after being exposed to water, so that the keyboard can adapt to a more severe environment.

(2), LED display: LED display is used for product promotion, store decoration, lighting, warning and so on. Some of its uses need to face the harsh environment of rain or dust, such as outdoor LED advertising screens in shopping malls, road warning lights, and LED display control panels in production workshops in rainy days. These harsh environments cause LED screens to fail and easy to accumulate dust. It is not easy to clean. After using the nano-coating, the above-mentioned problems can be effectively solved.

(3) Intelligent fingerprint lock: Fingerprint lock is an intelligent lock, which integrates computer information technology, electronic technology, mechanical technology and modern hardware technology, and is widely used in public security criminal investigation and judicial fields. However, after it encounters water, its internal circuit is prone to short circuit, which is difficult to repair and needs to be violently dismantled. After using this coating, this problem can be avoided.

(4) Hearing aids and Bluetooth headsets: Neither hearing aids nor Bluetooth headsets have communication lines. After using this coating, users can use it in a water environment for a certain period of time. damage.

(5) Some sensors: Some sensors need to work in a liquid environment, such as water pressure, oil pressure sensors, sensors used in underwater operating equipment, and sensors that often encounter water in the working environment. After layering, it can be guaranteed that the sensor will not fail due to liquid intrusion into the internal structure of the mechanical equipment.

(6), most 3C products: such as mobile phones, notebooks, PSP, etc.

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

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

Waterproof, moisture-proof and mildew-proof:

1House interior: bathroom top surface, wallpaper, chandeliers, curtains, screens. 2 daily necessities: mosquito nets, lampshades, chopsticks baskets, car rearview mirrors. 3 Cultural relics and works of art: copybooks, antiques, wood carvings, leather, bronzes, silk, ancient costumes, ancient books. 4 Electronic components and electronic products: sensors (operating in humid 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, alkaline solvent, acid, alkaline salt spray, acidic 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 lubricating oil), pipelines, valves, lining of large-diameter marine pipelines, etc. 4 Various reaction kettles and reactors. 5. Production and storage of chemicals; sewage treatment, aeration tank; 6. Others: acid-base workshop, alkali-proof aerospace, energy and power, iron and steel metallurgy, petrochemical, medical and other industries, storage containers, statues (to reduce acid rain on its Corrosion), sensor (acid/alkaline environment).

Resistance to immersion in organic solvents, cosmetics, and sweat:

1 Such as paraffins, olefins, alcohols, aldehydes, amines, esters, ethers, ketones, aromatic hydrocarbons, hydrogenated hydrocarbons, terpene hydrocarbons, halogenated hydrocarbons, heterocyclic compounds, nitrogen-containing compounds and sulfur-containing compound solvents, etc.; 2 Cosmetic packaging containers ; 3 fingerprint locks, earphones.

Resistance to cold and heat cycles (-40°C to +75°C), resistance to alternating humidity and heat (humidity 75% to 95%): electrical, electronics, automotive appliances, such as aviation, automobiles, home appliances, scientific research and other equipment.

Detailed ways

The following specific examples describe the present invention in detail, but the present invention is not limited to the specific examples.

Example 1

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, comprising the following steps:

(1) The base material is placed in the reaction chamber of the nano-coating preparation equipment, the reaction chamber is closed and the reaction chamber is continuously evacuated, the vacuum degree in the reaction chamber is evacuated to 10 millitorr, and the inert gas Ar is passed into, Turn on the motion mechanism to make the substrate move in the reaction chamber;

In step (1), the substrate is a solid material, and the solid material is a block-shaped polytetrafluoroethylene plate and an electrical component, and any interface of the substrate surface can be exposed to GJB150.10A-2009 after the coating is prepared. It is used in the mold test environment, and any interface of the electrical component can be exposed to the environment described in the international industrial waterproof grade standard IPX7 after the coating is prepared on the surface.

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

In step (1), the substrate moves in the reaction chamber, and the substrate moves in a circular motion relative to the reaction chamber at a speed of 1 revolution/min.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 30 mTorr, turn on the plasma discharge, and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 400W, and the continuous discharge time is 60s, and then enters the coating stage, and the plasma discharge power is adjusted to 75W, and the continuous discharge time is 600s;

(4) cyclically repeating the pretreatment stage and coating stage in step (3) for 11 times, and preparing a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The introduction of monomer steam is to atomize and volatilize the monomer through the feeding pump, and introduce it into the reaction chamber at a low pressure of 10 mTorr, and the flow rate of the monomer steam is 1000 μL/min;

The monomer steam composition is:

A mixture of two monofunctional unsaturated fluorocarbon resins and two multifunctional unsaturated hydrocarbon derivatives, the mass fraction of multifunctional unsaturated hydrocarbon derivatives in the monomer vapor is 30%;

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

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

The plasma discharge mode in steps (3) and (4) is continuous radio frequency discharge.

(5) After the coating is finished, stop feeding the raw material monomer steam, stop the plasma discharge at the same time, continue to vacuumize, keep the vacuum degree of the reaction chamber at 10 mTorr, and let the atmosphere reach an atmospheric pressure after 1 minute, and then take out the substrate. .

The performance test results of the obtained polytetrafluoroethylene plate deposited with anti-mold coating are as follows:

The obtained electrical components deposited with a waterproof and electric breakdown resistant coating were tested for underwater immersion at different voltages as follows:

The results of the IPX 7 waterproof level test (1m submersion test for 30min) of the electrical components deposited with the waterproof and electric breakdown resistant coating are as follows:

Example 2

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, comprising the following steps:

(1) Place the substrate in the reaction chamber of the nano-coating preparation equipment, close the reaction chamber and continuously evacuate the reaction chamber, pump the vacuum in the reaction chamber to 60 millitorr, feed inert gas He, and start Motion mechanism to make the base material move;

In step (1), the substrate is a solid material, and the solid material is a block-shaped polytetrafluoroethylene plate and an electrical component, and any interface of the substrate surface can be exposed to GJB150.10A-2009 after the coating is prepared. It is used in the mold test environment, and any interface of the electrical component can be exposed to the environment described in the international industrial waterproof grade standard IPX7 after the coating is prepared on the surface.

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

In step (1), the base material performs planetary motion, with a revolution speed of 2 revolutions/min and an autorotation speed of 2.5 revolutions/min.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 90 mTorr, turn on the plasma discharge and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 120W, and the continuous discharge time is 450s, and then enters the coating stage, and the plasma discharge power is adjusted to 10W, and the continuous discharge time is 3600s;

(4) cyclically repeat the pretreatment stage and the coating stage in step (3) once, and prepare a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The introduction of the monomer steam is to atomize and volatilize the monomer through the feeding pump, and introduce it into the reaction chamber at a low pressure of 60 mTorr, and the flow rate of the monomer steam is 500 μL/min;

The monomer steam composition is:

A mixture of three monofunctional unsaturated fluorocarbon resins and two multifunctional unsaturated hydrocarbon derivatives, the mass fraction of multifunctional unsaturated hydrocarbon derivatives in the monomer vapor is 45%;

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

The polyfunctional unsaturated hydrocarbon derivatives are: tripropylene glycol diacrylate and polyethylene glycol diacrylate;

The plasma discharge mode in steps (3) and (4) is intermediate frequency continuous discharge, and the waveform of intermediate frequency discharge is bipolar pulse.

(5) After the coating is finished, stop feeding the steam of the raw material monomer, stop the plasma discharge at the same time, continue to vacuumize, keep the vacuum of the reaction chamber at 80 mTorr, and after 2 minutes, let the atmosphere reach an atmospheric pressure, and then take out the substrate. .

The performance test results of the obtained polytetrafluoroethylene plate deposited with anti-mold coating are as follows:

The obtained electrical components deposited with a waterproof and electric breakdown resistant coating were tested for underwater immersion at different voltages as follows:

The results of the IPX 7 waterproof level test (1m submersion test for 30min) of the electrical components deposited with the waterproof and electric breakdown resistant coating are as follows:

Example 3

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, comprising the following steps:

(1) Place the substrate in the reaction chamber of the nano-coating preparation equipment, close the reaction chamber and continuously evacuate the reaction chamber, pump the vacuum in the reaction chamber to 130 millitorr, feed inert gas Ar, and start Motion mechanism to make the base material move;

In step (1), the base material is a solid material, and the solid material is a block alloy steel plate material, and any interface of the base material surface can be exposed to an organic solvent test environment after preparing an organic solvent immersion-resistant and cosmetic-resistant coating middle.

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

In step (1), the base material performs circular motion at a speed of 4 revolutions/min.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 150 mTorr, turn on the plasma discharge and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 200W, and the continuous discharge time is 150s, and then enters the coating stage, and the plasma discharge power is adjusted to 20W, and the continuous discharge time is 1000s;

(4) cyclically repeating the pretreatment stage and coating stage in step (3) for 6 times, and preparing a multifunctional nano-coating by chemical vapor deposition on the surface of the substrate;

In step (2):

The introduction of monomer steam is to atomize and volatilize the monomer through the feed pump, and introduce it into the reaction chamber at a low pressure of 10 mTorr, and the flow rate of the monomer steam is 550 μL/min;

The monomer steam composition is:

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

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

The polyfunctional unsaturated hydrocarbon derivatives are: ethoxylated trimethylolpropane triacrylate and diethylene glycol divinyl ether;

The plasma discharge mode in steps (3) and (4) is high-frequency continuous discharge, and the waveform of the high-frequency discharge is sinusoidal.

(5) After the coating is finished, stop feeding the steam of the raw material monomer, stop the plasma discharge at the same time, continue to vacuumize, keep the vacuum degree of the reaction chamber at 130 mTorr, and after 3 minutes, let the atmosphere reach an atmospheric pressure, and then take out the substrate. .

After the above-mentioned alloy steel plate material is coated, the results of the organic solvent resistance test are as follows:

Example 4

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, comprising the following steps:

(1) Place the substrate in the reaction chamber of the nano-coating preparation equipment, close the reaction chamber and continuously evacuate the reaction chamber, pump the vacuum in the reaction chamber to 160 millitorr, feed inert gas He, and start Motion mechanism to make the base material move;

In step (1), the base material is a solid material, and the solid material is a block aluminum alloy material, and any interface of the base material surface can be exposed to acid and alkali test environments after preparing an acid-resistant and alkaline environmental coating .

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

In step (1), the base material performs linear reciprocating motion at a speed of 20 mm/min.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 190 mTorr, turn on the plasma discharge and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 300W, and the continuous discharge time is 250s, and then enters the coating stage, and the plasma discharge power is adjusted to 35W, and the continuous discharge time is 2000s;

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

In step (2):

The introduction of monomer steam is to atomize and volatilize the monomer through the feeding pump, and introduce it into the reaction chamber at a low pressure of 160 mTorr, and the flow rate of the monomer steam is 220 μL/min;

The monomer steam composition is:

A mixture of three monofunctional unsaturated fluorocarbon resins and three polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of multifunctional unsaturated hydrocarbon derivatives in the monomer vapor is 35%;

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;

The plasma discharge mode in steps (3) and (4) is microwave continuous discharge.

(5) After the coating is finished, stop feeding the steam of the raw material monomer, stop the plasma discharge at the same time, continue to vacuumize, keep the vacuum degree of the reaction chamber at 160 mTorr, and let the atmosphere reach an atmospheric pressure after 4 minutes, and then take out the substrate. .

The acid and alkali resistance test results of the above-mentioned bulk aluminum alloy material after coating are as follows:

Example 5

A method for preparing a multifunctional nano-protective coating by cyclic low-power continuous discharge, comprising the following steps:

(1) Place the substrate in the reaction chamber of the nano-coating preparation equipment, close the reaction chamber and continuously evacuate the reaction chamber, pump the vacuum in the reaction chamber to 200 millitorr, feed inert gas Ar, and start Motion mechanism to make the base material move;

In step (1), the base material is a solid material, and the solid material is an electronic component, and any interface of the base material can be exposed to a damp heat test environment after the wet heat-resistant alternating coating is prepared on the surface of the base material.

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

In step (1), the base material performs planetary motion, the planetary revolution speed is 1 revolution/min, and the planetary rotation speed is 1.5 revolutions/min.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 300 mTorr, turn on the plasma discharge and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 150W, and the continuous discharge time is 400s, and then enters the coating stage, and the plasma discharge power is adjusted to 55W, and the continuous discharge time is 3000s;

(4) cyclically repeat the pretreatment stage and the coating stage in step (3) twice, and prepare a multifunctional nano-coating on the surface of the substrate by chemical vapor deposition;

In step (2):

The introduction of monomer steam is to atomize and volatilize the monomer through the feeding pump, and introduce it into the reaction chamber at a low pressure of 200 mTorr, and the flow rate of the introduction of monomer steam is 10 μL/min;

The monomer steam composition is:

A mixture of three monofunctional unsaturated fluorocarbon resins and two multifunctional unsaturated hydrocarbon derivatives, the mass fraction of multifunctional unsaturated hydrocarbon derivatives 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 derivatives are: tripropylene glycol diacrylate and ethylene glycol diacrylate;

The plasma discharge mode in steps (3) and (4) is spark discharge.

(5) After the coating is finished, stop feeding the raw material monomer steam, stop the plasma discharge at the same time, continue to vacuumize, keep the vacuum degree of the reaction chamber at 200 mTorr, and after 5 minutes, let the atmosphere reach an atmospheric pressure, and then take out the substrate. .

The above-mentioned electronic components after coating, the results of the humidity and heat alternating test are as follows:

Example 6

The basic process steps of this embodiment are the same as those of Example 1, and the different process parameters are as follows:

1. In step (1), the vacuum in the reaction chamber is evacuated to 120 millitorr, and the inert gas Ar is introduced;

Step (1) The base material is a solid material, the solid material is a block aluminum material and a printed circuit board, and any interface of the base material surface can be exposed to cold and heat after the cold and heat cycle impact coating is prepared. in a loop test environment.

In step (1), the volume of the reaction chamber is 400 L, the temperature of the reaction chamber is controlled at 40° C., and the flow rate of the inert gas is 150 sccm.

(2) Feed the monomer vapor into the reaction chamber, and when the vacuum degree is 160 mTorr, turn on the plasma discharge and carry out chemical vapor deposition;

(3) The deposition process includes a pretreatment stage and a coating stage. In the pretreatment stage, the plasma discharge power is 180W, and the continuous discharge time is 200s, and then enters the coating stage, and the plasma discharge power is adjusted to 60W, and the continuous discharge time is 1500s;

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

In step (2): the introduction of monomer steam is to atomize and volatilize the monomer through the feed pump, and introduce it into the reaction chamber at a low pressure of 160 mTorr, and the flow rate of the introduction of monomer steam is 200 μL/min;

The monomer steam composition is:

A mixture of four monofunctional unsaturated fluorocarbon resins and two multifunctional unsaturated hydrocarbon derivatives, the mass fraction of multifunctional unsaturated hydrocarbon derivatives in the monomer vapor is 45%;

The monofunctional unsaturated fluorocarbon resins are: 2-(perfluorodecyl)ethyl methacrylate, 1H,1H,2H,2H-perfluorooctyl acrylate, 3,3,3-trifluoro - 1-propyne and 2-(perfluorohexyl)ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivatives are: tripropylene glycol diacrylate and diethylene glycol divinyl ether;

2. In step (5), keep the vacuum degree of the reaction chamber at 160 mTorr for 5 minutes, and then ventilate the atmosphere to an atmospheric pressure.

The above-mentioned coated aluminum materials and printed circuit boards, the impact test results of cold and hot cycles are as follows:

Claims (7)

1. a kind of method that cycle small-power continuous discharge prepares multi-functional nano protecting coating, it is characterised in that：Including with Lower step：

(1) base material is placed in the reaction chamber of nano coating Preparation equipment, reaction chamber is continuously vacuumized, by reaction chamber Interior vacuum degree is extracted into 10~200 millitorrs, and is passed through inert gas He or Ar, and opening movement mechanism makes base material in reaction chamber Indoor generation campaign；

(2) it is passed through in monomer vapours to reaction chamber, until vacuum degree is 30~300 millitorrs, opens plasma discharge, changed Learn vapor deposition；

(3) deposition process include pretreatment stage and plating mem stage, pretreatment stage plasma discharge power be 120~ 400W, 60~450s of continuous discharging time, subsequently into plating mem stage, adjustment plasma discharge power is 10~75W, is continued 600~3600s of discharge time；

(4) in circulating repetition step (3) pretreatment stage and plating mem stage at least once, in substrate surface chemical vapor deposition system Standby multifunctionality nano coating；

The monomer vapours ingredient is：

The mixture of at least one single functionality unsaturation fluorocarbon resin and at least one polyfunctionality unsaturated hydrocarbons analog derivative, Mass fraction in the monomer vapours shared by polyfunctionality unsaturated hydrocarbons analog derivative is 15~65%；

The single functionality unsaturation fluorocarbon resin includes：

3- (perfluor -5- methylhexyls) -2- hydroxy propyl methacrylates, 2- (perfluoro decyl) ethylmethyl acrylate, 2- (perfluoro hexyl) ethylmethyl acrylate, 2- (perfluorododecyl) ethyl propylenes acid esters, 2- perfluoro capryl acrylic acid second Ester, 1H, 1H, 2H, 2H- perfluorooctanols acrylate, 2- (perfluoro butyl) ethyl propylenes acid esters, (2H- perfluoro propyls) -2- propylene Acid esters, (perfluorocyclohexyl) methacrylate, tri- fluoro- 1- propine of 3,3,3-, 1- acetenyl -3,5- difluorobenzenes or 4- acetenyls Benzotrifluoride；

The polyfunctionality unsaturated hydrocarbons analog derivative includes：

Ethoxylated trimethylolpropane triacrylate, tri (propylene glycol) diacrylate, polyethyleneglycol diacrylate, 1,6 hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol divinyl ether or diacrylic acid pentyl diol ester；

(5) stop being passed through monomer vapours, be simultaneously stopped plasma discharge, persistently vacuumize, holding reaction chamber vacuum degree is It is passed through air after 10~200 1~5min of millitorr to an atmospheric pressure, stops the movement of base material, then takes out base material.

2. a kind of cycle small-power continuous discharge according to claim 1 prepares the side of multi-functional nano protecting coating Method, it is characterised in that：Base material generates movement in reaction chamber in the step (1), and substrate transport form is that base material is relatively anti- Chamber is answered to carry out straight reciprocating motion or curvilinear motion, the curvilinear motion includes circular motion, ellipse circular motion, planet fortune Dynamic, spheric motion or the curvilinear motion of other irregular routes.

3. a kind of cycle small-power continuous discharge according to claim 1 prepares the side of multi-functional nano protecting coating Method, it is characterised in that：Base material is solid material in the step (1), and the solid material is electronic product, electric component, electricity Subgroup fills semi-finished product, pcb board, metallic plate, polytetrafluoroethylene (PTFE) plank or electronic component, and the substrate surface prepares more work( Its any interface can be exposed to water environment, mould environment, acid, basic solvent environment, acid, alkaline salt fog ring after energy property nano coating Border, acidic atmosphere environment, organic solvent impregnate environment, cosmetics environment, sweat environment, cold cycling shock environment or damp and hot friendship It is used in changing environment.

4. a kind of cycle small-power continuous discharge according to claim 1 prepares the side of multi-functional nano protecting coating Method, it is characterised in that：The volume of reaction chamber is 50~1000L in the step (1), the temperature control of reaction chamber 30~ 60 DEG C, it is 5~300sccm that the inert gas, which is passed through flow,.

5. a kind of cycle small-power continuous discharge according to claim 1 or 4 prepares multi-functional nano protecting coating Method, it is characterised in that：The reaction chamber is rotator shaped chamber or cube shaped chamber.

6. a kind of cycle small-power continuous discharge according to claim 1 prepares the side of multi-functional nano protecting coating Method, it is characterised in that：In the step (2)：It is to be atomized monomer by charge pump, volatilize and by low to be passed through monomer vapours 10~200 millitorrs are pressed to introduce reaction chamber, the flow for being passed through monomer is 10~1000 μ L/min.

7. a kind of cycle small-power continuous discharge according to claim 1 prepares the side of multi-functional nano protecting coating Method, it is characterised in that：In the step (3) and (4), plasma discharge manner is that radio frequency discharge, microwave discharge, intermediate frequency are put The waveform of electricity, high-frequency discharge or spark discharge, the high-frequency discharge and intermediate frequency electric discharge is sinusoidal or bipolar pulse.