A mobile hot-wire CVD coating preparation device and its spraying method

Abstract

This invention discloses a mobile hot-wire CVD coating preparation device and its spraying method. The device includes a reaction chamber with an air inlet at the rear and an air outlet at the front. Several sets of hot wires are arranged in the chamber along the airflow direction for catalytic decomposition of the reaction gas to generate active groups. A protective gas channel is provided on the outside of the reaction chamber to isolate the active groups from the external atmosphere. The device can also be equipped with an RF coil and a DC bias device to ionize the active groups and accelerate their deposition onto the substrate surface. The spraying method includes: introducing an inert gas to purge the air from the chamber, heating the hot wires to a preset temperature, introducing the reaction gas and catalytically decomposing it through the hot wires to generate active groups, and depositing the active groups onto the substrate surface under the action of the airflow to form a coating. This invention does not require a high vacuum system, can achieve coating preparation under normal pressure, has low cost, and the device is mobile, making it suitable for substrate surfaces of different sizes and shapes.

Description

Technical Field

[0001] This invention relates to the field of surface coating preparation technology, specifically to a mobile hot-wire CVD coating preparation device and its spraying method. Background Technology

[0002] Coatings play a vital role in production and daily life. Besides their decorative function, some special functional coatings can also provide corrosion resistance, wear resistance, and hydrophobicity. Common coating preparation techniques include physical coating, thermal spraying, electrochemical coating, and vacuum deposition.

[0003] Currently, common coating preparation technologies have the following shortcomings: physical coating methods are only applicable to organic coatings, limiting the types of coatings; thermal spraying methods are prone to incomplete melting of individual particles during construction, resulting in particulate impurities in the coating, affecting the integrity of the coating and causing functional coating failure; electrochemical coating processes require conductive substrates, and surface conductive treatment is required for non-conductive substrates, which is a complicated process and limits the types of coatings that can be deposited; vacuum coating processes generally require high vacuum systems, which are relatively expensive, and specific vacuum chambers are not compatible with substrates of different shapes and sizes, limiting their wide application. Summary of the Invention

[0004] The purpose of this invention is to provide a mobile hot-wire CVD coating preparation device and its spraying method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a mobile hot-wire CVD coating preparation device, comprising a reaction chamber, wherein an air inlet is provided at the tail end of the reaction chamber and an air outlet is provided at the front end of the reaction chamber, and a plurality of hot wires are arranged in the reaction chamber along the airflow direction, wherein the hot wires are used to catalytically decompose the reaction gas to generate active groups; a protective gas channel is provided on the outside of the reaction chamber, wherein the protective gas channel is provided with a protective gas inlet for introducing protective gas to isolate the active groups from the external atmosphere.

[0006] Preferably, the hot wires are arranged in 2 to 5 groups along the airflow direction.

[0007] Preferably, a radio frequency coil is provided at the air outlet.

[0008] Preferably, a DC bias device is provided at the air outlet.

[0009] The present invention also provides a spraying method based on the above-mentioned equipment, comprising the following steps: S1: Align the air outlet of the device with the substrate to be coated; S2: Inert gas is introduced into the air inlet to purge the air from the reaction chamber; S3: The hot wire is energized and heated to a preset temperature, while protective gas is introduced into the protective gas inlet; S4: A reaction gas is introduced into the air inlet. When the reaction gas passes through the hot wire, it is catalytically decomposed by the hot wire to produce active groups. S5: Active groups are discharged from the outlet under the action of airflow and deposited on the substrate surface to form a coating.

[0010] Preferably, the heating temperature of the hot wire in step S3 is 600℃~1800℃. Preferably, the protective gas in step S3 is an inert gas.

[0011] Preferably, when the device includes the radio frequency coil and the DC bias device, the method further includes: A DC bias voltage is applied between the air outlet and the substrate, and the output power of the radio frequency coil is adjusted. The active groups move to the outlet under the action of the airflow and are ionized into charged ions by the radio frequency coil. Charged ions are accelerated to the substrate surface under the action of the accelerating electric field generated by DC bias, and deposited to form a coating.

[0012] Preferably, the reaction gas includes at least one of hexamethyldisilazane, triethylsilane, pentachlorosilane, hexafluoropropylene oxide, and perfluorobutylsulfonyl fluoride.

[0013] Preferably, the coating comprises one of a SiNx coating, a Si coating, or a polytetrafluoroethylene coating.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention is based on hot-filament CVD technology, using a gaseous precursor as the coating source. The deposited components are gaseous active groups, eliminating the problem of solid particle inclusions affecting coating quality and enabling the preparation of high-quality coatings with nanometer-scale thicknesses. This invention requires no vacuum system and can achieve coating preparation under ambient pressure, effectively reducing coating preparation costs. Furthermore, the equipment is portable and not limited by the size of the vacuum chamber, allowing for coating preparation on substrates of different sizes and shapes. In addition, by incorporating an RF coil and a DC bias device, this invention can ionize the active groups and accelerate their deposition onto the substrate surface, improving the adhesion between the coating and the substrate material. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the mobile hot-wire CVD coating preparation equipment of the present invention; Figure 2 This is a schematic diagram of the ionization spraying equipment with radio frequency coil and DC bias device of the present invention.

[0016] In the diagram: 1. Reaction chamber; 2. Inlet; 3. Outlet; 4. Hot wire; 5. Protective gas channel; 6. Protective gas inlet; 7. Substrate; 8. Radio frequency coil; 9. DC bias device; 10. Coating. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, a mobile hot-wire CVD coating preparation device includes a reaction chamber 1, which is tubular in shape with an inlet 2 at the rear and an outlet 3 at the front. The reaction gas enters the reaction chamber 1 through the inlet 2, flows along the airflow direction, and exits through the outlet 3. Several sets of hot wires 4 are arranged inside the reaction chamber 1 along the airflow direction. The hot wires 4 are heated to a preset temperature by an electric current to catalytically decompose the reaction gas passing over their surface, causing the reaction gas to decompose and generate active atoms or active groups. Two to five sets of hot wires 4 can be arranged along the airflow direction. Multiple sets of hot wires 4 are arranged sequentially along the airflow direction, and the reaction gas is catalytically decomposed step-by-step as it flows through each set of hot wires 4, thus ensuring the complete decomposition of the reaction gas.

[0019] A protective gas channel 5 is provided on the outer side of the reaction chamber 1. The protective gas channel 5 is located between the outer shell of the reaction chamber 1 and the outer shell, forming a sandwich structure surrounding the reaction chamber 1. The protective gas channel 5 is provided with a protective gas inlet 6. During the preparation of the coating 10, protective gas is introduced into the protective gas channel 5 through the protective gas inlet 6. The protective gas is discharged from the end of the protective gas channel 5, forming a protective gas atmosphere around the gas outlet 3. This isolates the active groups discharged from the gas outlet 3 from the outside air, preventing the active groups from reacting with components such as oxygen in the outside atmosphere and losing their activity before reaching the surface of the substrate 7. This ensures that the active groups deposited on the surface of the substrate 7 have sufficient chemical activity to form a high-quality coating 10.

[0020] Before coating 10 is prepared, air inlet 2 is also used to introduce inert gas to purge the residual air in reaction chamber 1, so as to avoid adverse reactions between oxygen and other components in the air and hot wire 4 or reaction gas at high temperature, which would affect the quality of coating 10.

[0021] like Figure 2As shown, based on the above-mentioned equipment, an RF coil 8 can also be provided at the air outlet 3. The RF coil 8 is arranged outside the pipe of the air outlet 3. When the active group moves to the air outlet 3 under the action of airflow, the RF electric field generated by the RF coil 8 ionizes the active group into positively charged ions. A DC bias device 9 is also provided at the air outlet 3. The positive terminal of the DC bias device 9 is connected to the air outlet 3, and the negative terminal is connected to the substrate 7, forming an accelerating electric field between the air outlet 3 and the substrate 7. The charged ions ionized by the RF coil 8 gain higher kinetic energy under the action of this accelerating electric field, and collide with and deposit onto the surface of the substrate 7 at a higher speed to form a coating 10. The high-speed moving charged ions deposited on the surface of the substrate 7 are beneficial to improving the adhesion between the coating 10 and the substrate 7, thereby obtaining a high-quality coating 10 with stronger adhesion.

[0022] The spraying method based on the above-mentioned mobile hot-wire CVD coating preparation equipment 10 includes the following steps: S1: Align the air outlet 3 of the device with the substrate 7 to be coated; S2: Inert gas is introduced into the air inlet 2 to purge the air from the reaction chamber 1; S3: The hot wire 4 is energized and heated to the preset temperature, while protective gas is introduced into the protective gas inlet 6; S4: The reaction gas is introduced into the air inlet 2. When the reaction gas passes through the hot wire 4, it is catalyzed and decomposed by the hot wire 4 to produce active groups. S5: The active groups are discharged from the outlet 3 under the action of airflow and deposited on the surface of the substrate 7 to form a coating 10.

[0023] When the device includes an RF coil 8 and a DC bias device 9, in step S2, a DC bias is applied between the outlet 3 and the substrate 7; in step S3, the output power of the RF coil 8 is adjusted; in step S5, the active group moves to the outlet 3 under the action of the airflow, is ionized into charged ions by the RF coil 8, and the charged ions are accelerated to the surface of the substrate 7 under the action of the accelerating electric field generated by the DC bias, and deposited to form a coating 10.

[0024] By reasonably setting the movement path and speed of the device relative to the substrate 7, it is possible to prepare the coating 10 on the surface of substrates of different sizes and shapes, and the thickness of the coating 10 can be controlled and adjusted.

[0025] The reactive gases used in this invention include, but are not limited to, at least one of hexamethyldisilazane, triethylsilylamine, pentachlorosilane, hexafluoropropylene oxide, and perfluorobutylsulfonyl fluoride. Depending on the type of reactive gas used, the reactive gas is catalytically decomposed by the hot filament 4 to produce different active groups, which can be deposited on the surface of the substrate 7 to form different types of functional coatings such as SiNx coating, Si coating, or polytetrafluoroethylene coating.

[0026] The spraying method of the present invention will be further described below through specific embodiments. Embodiments 1 and 2 are spraying methods using a mobile hot-wire CVD coating preparation equipment for gas flow deposition, and Embodiments 3 and 4 are ionization spraying methods using equipment with an RF coil 8 and a DC bias device 9.

[0027] Example 1: In the device used in this example, four sets of hot wires 4 are arranged in the reaction chamber 1 along the airflow direction.

[0028] S1: Align the air outlet 3 of the equipment with the substrate 7 to be coated.

[0029] S2: Introduce 1000 sccm of Ar into the air inlet 2 and continue for 10 minutes to purge the air from the reaction chamber 1.

[0030] S3: The temperature of the hot wire 4 is raised to 1800℃ by electric heating, while 1000 sccm of N2 is introduced into the protective gas inlet 6.

[0031] S4: 200 sccm of hexamethyldisilazane is introduced into the air inlet 2. After entering the reaction chamber 1, hexamethyldisilazane decomposes into active Si atoms and N atoms under the catalytic action of the high-temperature hot wire 4.

[0032] S5: The active Si and N atoms decomposed from the hot filament 4 are discharged from the outlet 3 under the action of airflow and deposited on the surface of the substrate 7 to form a SiNx coating.

[0033] Example 2: In the device used in this example, 5 sets of hot wires 4 are arranged in the reaction chamber 1 along the airflow direction.

[0034] S1: Align the air outlet 3 of the equipment with the substrate 7 to be coated.

[0035] S2: Introduce 1000 sccm of Ar into the air inlet 2 and continue for 10 minutes to purge the air from the reaction chamber 1.

[0036] S3: The temperature of the hot wire 4 is raised to 600°C by electric heating, while 1000 sccm of N2 is introduced into the protective gas inlet 6.

[0037] S4: 20 sccm of hexafluoropropylene oxide and 8 sccm of perfluorobutyl sulfonyl fluoride are introduced into the air inlet 2. After the two precursors enter the reaction chamber 1, they decompose into active CF2 groups and C4F9 groups under the catalytic action of the high-temperature hot wire 4.

[0038] S5: The active CF2 and C4F9 groups decomposed from the hot wire 4 are discharged from the outlet 3 under the action of airflow and deposited on the surface of the substrate 7 to form a polytetrafluoroethylene coating.

[0039] Example 3: In the device used in this example, two sets of hot wires 4 are arranged in the reaction chamber 1, and an RF coil 8 and a DC bias device 9 are provided at the gas outlet 3.

[0040] S1: Align the air outlet 3 of the equipment with the substrate 7 to be coated.

[0041] S2: Introduce 1000 sccm of Ar into the air inlet 2 and continue for 10 minutes to purge the air from the reaction chamber 1. At the same time, connect the air outlet 3 to the positive terminal of the DC bias device 9 and the base 7 to the negative terminal, and adjust the output voltage of the DC bias device 9 to 200V.

[0042] S3: Heat the hot wire 4 to 1600℃, and at the same time introduce 1000sccm of N2 into the protective gas inlet 6, and adjust the power of the RF coil 8 to 80W.

[0043] S4: 200 sccm of triethylsilylamine is introduced into the air inlet 2. After entering the reaction chamber 1, the triethylsilylamine is decomposed into active Si atoms and N atoms under the catalytic action of the hot wire 4.

[0044] S5: Active Si and N atoms move to the outlet 3 under the action of airflow, are ionized into positively charged ions by the radio frequency coil 8, and then accelerate to the surface of the substrate 7 under the action of the accelerating voltage between the substrate 7 and the outlet 3 to form a SiNx coating.

[0045] Example 4: In the device used in this example, three sets of hot wires 4 are arranged in the reaction chamber 1, and an radio frequency coil 8 and a DC bias device 9 are provided at the gas outlet 3.

[0046] S1: Align the air outlet 3 of the equipment with the substrate 7 to be coated.

[0047] S2: Introduce 1000 sccm of Ar into the air inlet 2 and continue for 10 minutes to purge the air from the reaction chamber 1. At the same time, connect the air outlet 3 to the positive terminal of the DC bias device 9 and the base 7 to the negative terminal, and adjust the output voltage of the DC bias device 9 to 100V.

[0048] S3: Heat the hot wire 4 to 1800℃, and at the same time introduce 1000sccm of N2 into the protective gas inlet 6, and adjust the power of the RF coil 8 to 80W.

[0049] S4: 200 sccm of pentachlorosilane is introduced into the air inlet 2. After entering the reaction chamber 1, the pentachlorosilane decomposes into active Si atoms under the catalytic action of the hot wire 4.

[0050] S5: Active Si atoms move to the outlet 3 under the action of airflow, are ionized into positively charged ions by the radio frequency coil 8, and then accelerate to the surface of the substrate 7 under the action of the accelerating voltage between the substrate 7 and the outlet 3 to form a Si coating.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A mobile hot-wire CVD coating preparation device, characterized in that: The device includes a reaction chamber with an air inlet at the rear and an air outlet at the front. Several sets of hot wires are arranged inside the reaction chamber along the airflow direction. The hot wires are used to catalyze the decomposition of the reaction gas to generate active groups. A protective gas channel is provided on the outside of the reaction chamber. The protective gas channel has a protective gas inlet for introducing protective gas to isolate the active groups from the external atmosphere.

2. The mobile hot-wire CVD coating preparation equipment according to claim 1, characterized in that: The hot wires are arranged in 2 to 5 groups along the airflow direction.

3. The mobile hot-wire CVD coating preparation equipment according to claim 2, characterized in that: A radio frequency coil is provided at the air outlet.

4. The mobile hot-wire CVD coating preparation equipment according to claim 3, characterized in that: A DC bias device is provided at the air outlet.

5. A spraying method based on the equipment described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1: Align the air outlet of the device with the substrate to be coated; S2: Inert gas is introduced into the air inlet to purge the air from the reaction chamber; S3: The hot wire is energized and heated to a preset temperature, while protective gas is introduced into the protective gas inlet; S4: A reaction gas is introduced into the air inlet. When the reaction gas passes through the hot wire, it is catalytically decomposed by the hot wire to produce active groups. S5: Active groups are discharged from the outlet under the action of airflow and deposited on the substrate surface to form a coating.

6. The spraying method according to claim 5, characterized in that: The heating temperature of the hot wire in step S3 is 600℃~1800℃.

7. The spraying method according to claim 5, characterized in that: The protective gas in step S3 is an inert gas.

8. The spraying method according to claim 5, characterized in that: When the device includes the radio frequency coil and the DC bias device, the method further includes: A DC bias voltage is applied between the air outlet and the substrate, and the output power of the radio frequency coil is adjusted. The active groups move to the outlet under the action of the airflow and are ionized into charged ions by the radio frequency coil. Charged ions are accelerated to the substrate surface under the action of the accelerating electric field generated by DC bias, and deposited to form a coating.

9. The spraying method according to claim 5, characterized in that: The reactant gas includes at least one of hexamethyldisilazane, triethylsilylamine, pentachlorosilane, hexafluoropropylene oxide, and perfluorobutylsulfonyl fluoride.

10. The spraying method according to claim 5, characterized in that: The coating includes one of SiNx coating, Si coating, or polytetrafluoroethylene coating.

Images