Method for plasma vapor deposition of aluminum oxide

Abstract

The invention provides a method for plasma vapor deposition of aluminum oxide, which comprises the following steps of: feeding an ETFE (Ethyl Tetra Fluoro Ethylene) film into a pretreatment area of a vacuum reaction cavity for plasma cleaning and activation; transferring the cleaned ETFE film to a deposition area of the vacuum reaction cavity, and heating the ETFE film at the temperature of 50-80 DEG C; aluminum methacrylate is injected into an evaporator to be gasified, oxygen is mixed with aluminum methacrylate steam, then the oxygen and the aluminum methacrylate steam are injected into a deposition area together, the conveying flow of the aluminum methacrylate is 0.1-1 sccm, and the conveying flow of the oxygen is 5-20 sccm; starting a radio frequency power supply to excite plasma in the deposition area, wherein the radio frequency power is 50-500 W; the ETFE film generating Al2O3 is transferred to a post-treatment area of a vacuum reaction cavity, oxygen plasma annealing operation is carried out, and the vacuum degree of the vacuum reaction cavity is 0.1-5 Pa. The coating obtained by the method has the advantages of better thickness uniformity, smaller roughness and fewer byproducts, so that the product has better barrier property, chemical resistance and mechanical property.

Description

Technical Field

[0001] The invention relates to the technical field of preparing metal coatings, and in particular to a method for plasma vapor deposition of aluminum oxide. Background Art

[0002] The plasma-assisted vapor deposition process of aluminum oxide has the problem of poor conformality. In addition, the process parameters of vapor deposition of aluminum oxide affect the thickness uniformity, roughness, and impurities of the coating, which in turn affects the barrier properties, chemical resistance, and mechanical properties of the product. Currently, the plasma-assisted vapor deposition process of aluminum oxide cannot achieve good barrier properties, chemical resistance, and mechanical properties at the same time. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a method for plasma vapor deposition of aluminum oxide, the coating obtained by this method has the advantages of good thickness uniformity, less roughness and fewer by-products, so that the product has better barrier properties, chemical resistance and mechanical properties.

[0004] In order to solve the above problems, the technical solutions adopted by the present invention are as follows: A method for plasma vapor deposition of aluminum oxide comprises the following steps: The ETFE film is sent into a pretreatment area of a vacuum reaction chamber and plasma cleaned and activated in the pretreatment area; Transferring the cleaned ETFE film to the deposition area of the vacuum reaction chamber and heating the ETFE film at a temperature of 50-80° C.; Aluminum methacrylate is injected into an evaporator for vaporization, oxygen is mixed into the aluminum methacrylate vapor, and the two are injected together into the deposition area. Inert gas is injected into the deposition area as a carrier gas. The aluminum methacrylate is delivered at a flow rate of 0.1-1 sccm, and the oxygen is delivered at a flow rate of 5-20 sccm. Starting a radio frequency power supply to excite plasma in the deposition area so that Al2O3 is generated on the surface of the ETFE film, with a radio frequency power of 50-500 W; The ETFE film on which Al2O3 is generated is transferred to the post-processing area of the vacuum reaction chamber and subjected to oxygen plasma annealing operation at a power of 100 W for 2 minutes. The vacuum degree of the vacuum reaction chamber in the above steps is 0.1-5 Pa.

[0005] In some possible implementations, the ETFE film is transported by a roll-to-roll process, and the moving speed of the ETFE film is 0.1-5 m / min.

[0006] In some possible implementations, the further step includes: outputting the ETFE film forming the Al2O3 layer out of the vacuum reaction chamber, cooling the film to room temperature via a cooling roller, and then rolling the film up.

[0007] In some possible implementations, the delivery flow rate of the aluminum methacrylate is 0.2-0.5 sccm, and the delivery flow rate of the oxygen is 10-15 sccm.

[0008] In some possible implementations, the moving speed of the ETFE film is 0.5-2 m / min.

[0009] In some possible embodiments, the RF power during the formation of Al2O3 is 100-300 W.

[0010] In some possible implementations, the radio frequency power of the pretreatment zone is 50 W, and the cleaning and activation time is 1-5 minutes.

[0011] In some possible implementations, the vacuum degree of the vacuum reaction chamber is 0.1-1 Pa.

[0012] In some possible embodiments, the vaporization temperature of the aluminum methacrylate is 80-120°C.

[0013] Compared with the prior art, the present invention has the following beneficial effects: In this application, the coordination of various process parameters ensures that the ETFE film containing Al2O3 exhibits excellent thickness uniformity, minimal roughness, and fewer byproducts, resulting in a product with excellent barrier properties, chemical resistance, and mechanical properties. Furthermore, by coordinating the delivery flow rate with the RF power, post-treatment steps, pre-treatment steps, and vacuum level, an aluminum oxide coating can be formed on the surface of the ETFE film at temperatures between 50°C and 80°C, thereby preventing thermal damage to the ETFE film substrate.

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flowchart of a method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0018] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0019] An embodiment of the present application provides a method for plasma vapor deposition of aluminum oxide, which includes the following steps.

[0020] Step S101: An ETFE (ethylene tetrafluoroethylene) film is placed in a pretreatment zone within a vacuum reaction chamber and plasma cleaned and activated. For example, Ar plasma cleaning and activation can be used. Cleaning removes contaminants from the film surface and increases the film's surface energy.

[0021] In some embodiments, the RF power in the pretreatment zone is 50 W, and the cleaning and activation time is 1–5 minutes. The combination of power and time improves the cleaning effect while increasing the surface energy to above 50 mN / m, thereby increasing the bonding strength between the metal oxide film and the polymer.

[0022] Step S102: The cleaned ETFE film is transferred to the deposition area of the vacuum reaction chamber and heated to a temperature of 50-80°C (e.g., 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C, or any range between these two values). This heating temperature prevents deformation of the ETFE film, thereby improving the product's conformability.

[0023] Step S103: Aluminum methacrylate is injected into the evaporator for gasification, oxygen is mixed into the aluminum methacrylate vapor, and the two are injected into the deposition area together. An inert gas is injected into the deposition area as a carrier gas. Exemplarily, the inert gas can be mixed with oxygen into the aluminum methacrylate vapor, or the inert gas can be injected into the deposition area independently. Exemplarily, the aluminum methacrylate vapor can be delivered by a mass flow controller. Exemplarily, oxygen can be injected into the delivery pipe of the aluminum methacrylate vapor for mixing. Exemplarily, the inert gas can be selected from one of Ar and N2. The addition of the inert gas is beneficial to assisting plasma stability. The aluminum methacrylate delivery rate is 0.1–1 sccm, for example, 0.1 sccm, 0.2 sccm, 0.3 sccm, 0.4 sccm, 0.5 sccm, 0.6 sccm, 0.7 sccm, 0.8 sccm, 0.9 sccm, 0.1 sccm, or a value in between. The oxygen delivery rate is 5–20 sccm, for example, 5 sccm, 10 sccm, 15 sccm, 20 sccm, or a value in between. The flow rates of aluminum methacrylate and oxygen are preferably selected to ensure that aluminum radicals are oxidized as aluminum oxide rather than aluminum oxide, ensuring that the organic ligands are completely oxidized to reduce carbon residues.

[0024] In some embodiments, the delivery flow rate of the aluminum methacrylate is 0.2-0.5 sccm, and the delivery flow rate of the oxygen is 10-15 sccm, thereby further ensuring the production of aluminum oxide and reducing carbon residue.

[0025] In some embodiments, the aluminum methacrylate has a vaporization temperature of 80-120°C, and can be, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 110°C, 120°C, or any value therebetween. The vaporization temperature is selected to prevent premature decomposition of the aluminum methacrylate.

[0026] Step S104: Activating a radio frequency power source to excite a plasma in the deposition zone, thereby generating Al2O3 on the surface of the ETFE film. The radio frequency power is 50-500 W, and can be, for example, 50 W, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, 500 W, or any value therebetween. The selected range of radio frequency power facilitates controlling the energy density of the plasma, thereby facilitating an increase in the generation rate of Al2O3, reducing byproducts, and reducing carbon residue.

[0027] In some embodiments, the RF power during the formation of Al2O3 is 100-300 W. Further reduction of the RF power is beneficial to further improve the yield of Al2O3 and reduce carbon residue.

[0028] Step S105: The ETFE film, after forming Al2O3, is transferred to the post-treatment zone of the vacuum reaction chamber and subjected to an oxygen plasma annealing operation at a power of 100 W for 2 minutes. The vacuum level of the vacuum reaction chamber in this step is 0.1-5 Pa, i.e., the vacuum level in the pre-treatment zone, deposition zone, and post-treatment zone is all 0.1-5 Pa. These annealing parameters can eliminate residual organic matter.

[0029] In some embodiments, the vacuum degree of the vacuum reaction chamber is 0.1-1 Pa. Further narrowing the range of vacuum degree is beneficial to maintaining plasma stability.

[0030] Step S106: The ETFE film with the Al2O3 layer formed thereon outputted from the vacuum reaction chamber is cooled to room temperature by a cooling roller and then rolled up, thereby facilitating reduction of stress accumulation.

[0031] In some embodiments, the ETFE film is transported via a roll-to-roll process, whereby a motor drives a material roller to rotate the ETFE film in different regions. The ETFE film is moved at a speed of 0.1–5 m / min, thereby facilitating control of coating thickness. This roll-to-roll process can improve mass production efficiency.

[0032] In some embodiments, the moving speed of the ETFE film is 0.5-2 m / min, so that the coating thickness is controlled at 50-200 nm. Example

[0033] A method for plasma vapor deposition of aluminum oxide comprises the following steps: introducing an ETFE film into a pretreatment zone of a vacuum reaction chamber, performing Ar plasma cleaning and activation in the pretreatment zone at a radio frequency power of 50 W for 2 minutes; transferring the cleaned ETFE film to a deposition zone of the vacuum reaction chamber, and heating the ETFE film at 50°C; injecting aluminum methacrylate into an evaporator for vaporization at a temperature of 90°C; mixing oxygen with the aluminum methacrylate vapor, and then injecting both into the deposition zone; injecting an inert gas as a carrier gas into the deposition zone; Ar gas, which can be mixed into the oxygen and aluminum methacrylate vapor; and delivering the aluminum methacrylate at a flow rate of 0.1 sccm and 5 sccm. Activating a radio frequency power supply to ignite a plasma in the deposition zone, causing Al2O3 to form on the surface of the ETFE film; and generating the Al2O3 on the surface of the ETFE film at a radio frequency power of 50 W. The ETFE film, after forming the Al2O3 layer, is transferred to a post-processing area of the vacuum reaction chamber and subjected to an oxygen plasma annealing operation at a power of 100 W for 2 minutes. The vacuum level of the vacuum reaction chamber during the above steps is 0.1 Pa. The method transports the ETFE film via a roll-to-roll process. The ETFE film is moved at a speed of 0.1 m / min. The ETFE film, after forming the Al2O3 layer, is cooled to room temperature via cooling rollers and then reeled up. Example

[0034] The differences from Example 1 are that the heating temperature of the ETFE film is 60°C, the flow rate of the aluminum methacrylate is 0.2 sccm, and the flow rate of the oxygen is 10 sccm. The vaporization temperature of the aluminum methacrylate is 80°C. When forming the Al2O3 coating, the radio frequency power is 100 W, and the vacuum level of the vacuum reaction chamber is 0.5 Pa. The movement speed of the ETFE film is 0.5 m / min. Example

[0035] The difference from Example 1 is that the delivery flow rate of the aluminum methacrylate is 0.5 sccm, the delivery flow rate of the oxygen is 15 sccm, and the moving speed of the ETFE film is 2 m / min. Example

[0036] The difference from Example 2 is that the vaporization temperature of aluminum methacrylate is 120°C, the radio frequency power is 300 W when the Al2O3 coating is generated, and the vacuum degree of the vacuum reaction chamber is 1 Pa. Example

[0037] The difference from Example 1 is that the delivery flow rate of the aluminum methacrylate is 0.6 sccm, and the delivery flow rate of the oxygen is 17 sccm. Example

[0038] The difference from Example 1 is that the delivery flow rate of the aluminum methacrylate is 0.6 sccm, the delivery flow rate of the oxygen is 17 sccm, the radio frequency power is 350 W when forming the Al2O3 coating, and the vacuum degree of the vacuum reaction chamber is 5 Pa. The moving speed of the ETFE film is 3 m / min. Example

[0039] The difference from Example 6 is that the delivery flow rate of the aluminum methacrylate is 1 sccm, the delivery flow rate of the oxygen is 20 sccm, the radio frequency power is 500 W when forming the Al2O3 coating, and the vacuum degree of the vacuum reaction chamber is 5 Pa. The moving speed of the ETFE film is 5 m / min.

[0040] Comparative Example 1 The difference from Example 1 is that the delivery flow rate of the aluminum methacrylate is 2 sccm, the delivery flow rate of the oxygen is 21 sccm, the vacuum degree of the vacuum reaction chamber is 6 Pa, the RF power during the formation of Al2O3 is 550 W, and the heating temperature of the ETFE film is 85°C.

[0041] Comparative Example 2 The difference from the comparative example is that the heating temperature of the ETFE film is 48°C.

[0042] The chemical compositions of the above examples and comparative examples were analyzed using XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier transform infrared spectroscopy). In Examples 1 through 7, the Al 2p peak was located at 74.5 eV, the O 1s peak was located at 531 eV, and the O / Al atomic ratio was approximately 1.5. In Examples 2 through 4, the carbon residue was less than 5 at.%, while in Examples 1, 5, and 7, the carbon residue was between 6 at.% and 7 at. In Comparative Examples 1 and 2, the O / Al atomic ratio was approximately 1.2, and the carbon residue was greater than 7 at.%.

[0043] The physical properties of the above examples and comparative examples were tested by AFM (atomic force microscope) and ellipsometer. The surface roughness Ra of the coatings in Examples 2 to 4 was less than 5 nm, and the coatings were dense and non-porous. The surface roughness Ra of the coatings in Examples 1 and 5 to 7 was between 6 nm and 8 nm. The surface roughness Ra of the coatings in Comparative Examples 1 and 2 was greater than 10 nm. The thickness uniformity of the coatings in Examples 2 to 4 was ±5%, the thickness uniformity of the coatings in Examples 1 and 5 to 7 was ±7%, and the thickness uniformity of the coatings in Comparative Examples 1 to 2 was ±10%. The refractive index of Examples 1 to 7 was 1.65–1.70, and the refractive index of Comparative Examples 1 to 2 was 1.5-1.55.

[0044] The barrier properties of the products were characterized by WVTR (water vapor transmission rate, tested at 38°C, 90% RH) and OTR (oxygen transmission rate, tested at 23°C, 0% RH). The products in Examples 2-4 had a water vapor transmission rate of less than 1 g / m² / day and an oxygen transmission rate of less than 1 cm³ / m² / day. The products in Examples 1, 5, and 7 had a water vapor transmission rate between 1 g / m² / day and 2 g / m² / day, and an oxygen transmission rate between 1 cm³ / m² / day and 3 cm³ / m² / day. The products in Comparative Examples 1 and 2 had a water vapor transmission rate greater than 5 g / m² / day and an oxygen transmission rate greater than 6 cm³ / m² / day.

[0045] In addition, the products of the above examples and comparative examples were subjected to chemical resistance testing. On the one hand, the products were immersed in a pH 2-12 solution for 24 hours to observe whether the coating corroded or fell off. On the other hand, the contact angle change was measured after wiping with acetone and ethanol. The products in Examples 1 to 7 showed no corrosion or shedding, while the products in Comparative Examples 1 to 2 showed partial corrosion and shedding. After wiping with an organic solvent, the contact angle change of the products in Examples 1 to 7 was less than 5°. The contact angle change of the products in Comparative Examples 1 and 2 was greater than 5°.

[0046] The mechanical properties of the above examples and comparative examples were tested using ASTM C1624 and IEC 62715-6-1. It was found that the products in Examples 1 to 7 had a critical load greater than 5 N, a curvature radius of 5 mm, and no cracks after 1000 cycles. The products in Comparative Examples 1 and 2 had a critical load less than 4 N, a curvature radius of 5 mm, and cracks appeared after 500 cycles.

[0047] In this application, the coordination of various process parameters ensures that the ETFE film containing Al2O3 exhibits excellent thickness uniformity, minimal roughness, and fewer byproducts, resulting in a product with excellent barrier properties, chemical resistance, and mechanical properties. Furthermore, by coordinating the delivery flow rate with the RF power, post-treatment steps, pre-treatment steps, and vacuum level, an aluminum oxide coating can be formed on the surface of the ETFE film at temperatures between 50°C and 80°C, thereby preventing thermal damage to the ETFE film substrate.

[0048] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A method for plasma vapor deposition of aluminum oxide, characterized in that: The steps include: The ETFE film is sent into a pretreatment area of a vacuum reaction chamber and plasma cleaned and activated in the pretreatment area; Transferring the cleaned ETFE film to the deposition area of the vacuum reaction chamber and heating the ETFE film at a temperature of 50-80° C.; Aluminum methacrylate is injected into an evaporator for vaporization, oxygen is mixed into the aluminum methacrylate vapor, and the two are injected together into the deposition area. Inert gas is injected into the deposition area as a carrier gas. The aluminum methacrylate is delivered at a flow rate of 0.1-1 sccm, and the oxygen is delivered at a flow rate of 5-20 sccm. Starting a radio frequency power supply to excite plasma in the deposition area so that Al2O3 is generated on the surface of the ETFE film, with a radio frequency power of 50-500 W; The ETFE film on which Al2O3 is generated is transferred to the post-processing area of the vacuum reaction chamber and subjected to an oxygen plasma annealing operation with a power of 100 W and a time of 2 minutes. The vacuum degree of the vacuum reaction chamber in the above steps is 0.1-5 Pa.

2. The method according to claim 1, wherein The ETFE film is transported by a roll-to-roll process, and the moving speed of the ETFE film is 0.1-5 m / min.

3. The method according to claim 2, wherein Also includes: The ETFE film forming the Al2O3 layer output from the vacuum reaction chamber is cooled to room temperature by a cooling roller and then rolled up.

4. The method according to any one of claims 1 to 3, wherein: The aluminum methacrylate is delivered at a flow rate of 0.2-0.5 sccm, and the oxygen is delivered at a flow rate of 10-15 sccm.

5. The method according to claim 2, wherein The moving speed of the ETFE film is 0.5-2 m / min.

6. The method according to claim 1, wherein The RF power during the formation of Al2O3 was 100–300 W.

7. The method according to claim 1, wherein The radio frequency power of the pretreatment zone is 50 W, and the cleaning and activation time is 1-5 minutes.

8. The method according to claim 1, wherein The vacuum degree of the vacuum reaction chamber is 0.1-1 Pa.

9. The method according to claim 1, wherein The vaporization temperature of the aluminum methacrylate is 80-120°C.

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