Method for plasma vapor deposition of aluminum trioxide

Abstract

The application provides a method for depositing aluminum trioxide by plasma vapor deposition, comprising the following steps: sending an ETFE film into a pretreatment area of a vacuum reaction chamber for plasma cleaning and activation; sending the cleaned ETFE film into a deposition area of the vacuum reaction chamber; heating the ETFE film at a temperature of 50-80 DEG C; injecting aluminum methacrylate into an evaporator for gasification, mixing oxygen into the aluminum methacrylate vapor, and then injecting the mixture into the deposition area, wherein the flow rate of the aluminum methacrylate is 0.1-1 sccm, and the flow rate of the oxygen is 5-20 sccm; starting a radio frequency power source to excite plasma in the deposition area, wherein the radio frequency power is 50-500 W; and sending the ETFE film with Al2O3 into a post-treatment area of the vacuum reaction chamber for oxygen plasma annealing, wherein the vacuum degree of the vacuum reaction chamber is 0.1-5 Pa. The coating obtained by the method has the advantages of good thickness uniformity, small roughness and less by-products, so that the product has good barrier property, chemical resistance and mechanical property.

Description

Technical Field

[0001] This invention relates to the technical field of preparing metal coatings, and specifically to a method for plasma vapor deposition of aluminum oxide. Background Technology

[0002] Plasma-assisted vapor deposition (PAD) of aluminum oxide has the problem of poor shape retention. In addition, the process parameters of ACD affect the thickness uniformity, roughness and impurities of the coating, which in turn affect the barrier properties, chemical resistance and mechanical properties of the product. At present, the PCD process cannot simultaneously achieve good barrier properties, chemical resistance and mechanical properties. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for plasma vapor deposition of aluminum oxide, wherein the coating obtained by the method has the advantages of good thickness uniformity, low roughness and fewer by-products, thereby enabling the product to have good barrier properties, chemical resistance and mechanical properties.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0005] A method for plasma vapor deposition of aluminum oxide includes the following steps:

[0006] The ETFE membrane is fed into the pretreatment zone of the vacuum reaction chamber, where it is then subjected to plasma cleaning and activation.

[0007] The cleaned ETFE membrane is transferred to the deposition zone of the vacuum reaction chamber and heated at a temperature of 50–80°C.

[0008] Aluminum methacrylate is injected into an evaporator to vaporize. Oxygen is mixed with the aluminum methacrylate vapor and then injected into the deposition zone together. An inert gas is injected into the deposition zone as a carrier gas. The flow rate of aluminum methacrylate is 0.1–1 sccm, and the flow rate of oxygen is 5–20 sccm.

[0009] The radio frequency power supply is turned on to excite plasma in the deposition region, so that Al2O3 is generated on the surface of the ETFE film, with a radio frequency power of 50–500 W.

[0010] The ETFE film that generates Al2O3 is transferred to the post-processing zone of the vacuum reaction chamber for oxygen plasma annealing 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.

[0011] In some possible implementations, the ETFE film is transported via a roll-to-roll process at a speed of 0.1–5 m / min.

[0012] In some possible implementations, the ETFE film forming the Al2O3 layer outside the vacuum reaction chamber is cooled to room temperature by a cooling roller and then wound up.

[0013] In some possible implementations, 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.

[0014] In some possible implementations, the ETFE membrane moves at a speed of 0.5–2 m / min.

[0015] In some possible implementations, the radio frequency power during Al2O3 formation is 100–300 W.

[0016] 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.

[0017] In some possible implementations, the vacuum level of the vacuum reaction chamber is 0.1-1 Pa.

[0018] In some possible implementations, the aluminum methacrylate has a vaporization temperature of 80–120°C.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] In this application, the coordination of various process parameters enables the Al2O3-containing ETFE membrane to exhibit advantages such as better thickness uniformity, lower roughness, and fewer byproducts, thereby resulting in a product with better barrier properties, chemical resistance, and mechanical properties. Furthermore, by coordinating the flow rate with RF power, post-processing steps, pre-processing steps, and vacuum levels, an alumina coating can be formed on the surface of the ETFE membrane at an environment of 50–80°C, thus helping to prevent thermal damage to the ETFE membrane substrate.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0022] Figure 1 A flowchart of a method provided in an embodiment of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] One embodiment of this application provides a method for plasma vapor deposition of aluminum oxide, the method comprising the following steps.

[0027] Step S101: The ETFE (ethylene-tetrafluoroethylene copolymer) membrane is fed into the pretreatment zone of the vacuum reaction chamber, where it undergoes plasma cleaning and activation. For example, Ar plasma cleaning and activation can be performed. Cleaning removes contaminants from the membrane surface and increases the membrane's surface energy.

[0028] In some embodiments, the radio frequency power of the pretreatment zone is 50 W, and the cleaning and activation time is 1–5 minutes. The combination of power and time helps to improve the cleaning effect while increasing the surface energy to above 50 mN / m, thereby improving the bonding strength between the metal oxide film and the polymer.

[0029] Step S102: Transfer the cleaned ETFE film to the deposition area of ​​the vacuum reaction chamber and heat the ETFE film at a temperature of 50–80°C (exemplary values ​​could be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C, or any two of the above values). The selection of the heating temperature prevents deformation of the ETFE film, thereby improving the shape retention of the product.

[0030] Step S103: Aluminum methacrylate is injected into the evaporator to vaporize. Oxygen is mixed into the aluminum methacrylate vapor, and both are injected together into the deposition zone. An inert gas is injected into the deposition zone 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 zone independently. Exemplarily, the aluminum methacrylate vapor can be delivered using 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 either Ar or N2. The addition of an inert gas is beneficial for assisting plasma stabilization. The aluminum methacrylate delivery flow rate is 0.1–1 sccm, for example, it can be 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 between these values. The oxygen delivery flow rate is 5–20 sccm, for example, it can be 5 sccm, 10 sccm, 15 sccm, 20 sccm or a value between these values. The appropriate values ​​for the aluminum methacrylate and oxygen delivery flow rates ensure that the aluminum radicals are oxidized as aluminum oxide rather than aluminum oxide, ensuring complete oxidation of the organic ligands to reduce carbon residue.

[0031] In some embodiments, the flow rate of aluminum methacrylate is 0.2–0.5 sccm, and the flow rate of oxygen is 10–15 sccm, thereby facilitating further production of aluminum oxide and reducing carbon residue.

[0032] In some embodiments, the vaporization temperature of the aluminum methacrylate is 80–120°C, and exemplaryly, it can be 80°C, 85°C, 90°C, 95°C, 100°C, 110°C, 120°C, or any value between the above. The selection of the vaporization temperature helps to avoid premature decomposition of the aluminum methacrylate.

[0033] Step S104: Activate the radio frequency (RF) power supply to excite plasma in the deposition zone, causing Al2O3 to form on the ETFE film surface. The RF power is 50–500 W, and exemplary values ​​can be 50 W, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, 500 W, or any value between these values. Selecting a suitable RF power range allows for control of the plasma energy density, thereby improving the Al2O3 formation rate and reducing byproducts and carbon residue.

[0034] In some embodiments, the radio frequency power during Al2O3 formation is 100–300 W. Further limiting the radio frequency power is beneficial for further increasing the yield of Al2O3 and reducing carbon residue.

[0035] Step S105: The ETFE film containing Al2O3 is transferred to the post-processing zone of the vacuum reaction chamber for oxygen plasma annealing at a power of 100 W for 2 minutes. The vacuum level of the vacuum reaction chamber in the above steps is 0.1-5 Pa, meaning the vacuum levels in the pre-treatment zone, deposition zone, and post-treatment zone are all 0.1-5 Pa. These annealing parameters eliminate residual organic matter.

[0036] In some embodiments, the vacuum level of the vacuum reaction chamber is 0.1-1 Pa. Further narrowing the range of vacuum levels is beneficial for maintaining plasma stability.

[0037] Step S106: The ETFE film forming the Al2O3 layer outside the vacuum reaction chamber is cooled to room temperature by a cooling roller and then wound up, which helps to reduce stress accumulation.

[0038] In some embodiments, the ETFE film is conveyed via a roll-to-roll process, i.e., the ETFE film is moved in different areas by a motor-driven roller, with the film moving at a speed of 0.1–5 m / min, thereby facilitating control of the coating thickness. The roll-to-roll process improves mass production efficiency.

[0039] In some embodiments, the ETFE film is moved at a speed of 0.5–2 m / min, thereby controlling the coating thickness to be 50–200 nm. Example

[0040] A method for plasma vapor deposition of aluminum oxide includes the following steps: An ETFE film is fed into a pretreatment zone of a vacuum reaction chamber, where it undergoes Ar plasma cleaning and activation at a radio frequency power of 50 W for 2 minutes. The cleaned ETFE film is then transferred to the deposition zone of the vacuum reaction chamber and heated to 50°C. Aluminum methacrylate is injected into an evaporator for vaporization at 90°C. Oxygen is mixed with the aluminum methacrylate vapor and injected into the deposition zone along with it. An inert gas, Ar, is injected into the deposition zone as a carrier gas; the inert gas can be mixed with the oxygen and aluminum methacrylate vapor. The flow rate of the aluminum methacrylate is 0.1 sccm, and the flow rate of the oxygen is 5 sccm. A radio frequency power supply is activated to excite plasma in the deposition zone, causing Al₂O₃ to form on the surface of the ETFE film at a radio frequency power of 50 W. The ETFE film with the Al2O3 layer formed is transferred to the post-processing zone of the vacuum reaction chamber for oxygen plasma annealing at a power of 100 W for 2 minutes. The vacuum level of the vacuum reaction chamber is 0.1 Pa during this step. The ETFE film is transported using a roll-to-roll process at a speed of 0.1 m / min. The ETFE film with the Al2O3 layer formed outside the vacuum reaction chamber is cooled to room temperature by cooling rollers and then wound up. Example

[0041] The difference from Example 1 is that the heating temperature of the ETFE membrane 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. During the formation of the Al₂O₃ coating, the radio frequency power is 100 W, and the vacuum level of the vacuum reaction chamber is 0.5 Pa. The moving speed of the ETFE membrane is 0.5 m / min. Example

[0042] The difference from Example 1 is that the aluminum methacrylate delivery flow rate is 0.5 sccm, the oxygen delivery flow rate is 15 sccm, and the ETFE membrane travels at a speed of 2 m / min. Example

[0043] 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

[0044] 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

[0045] The difference from Example 1 is that the aluminum methacrylate delivery flow rate is 0.6 sccm, the oxygen delivery flow rate is 17 sccm, the radio frequency power is 350 W when generating the Al2O3 coating, and the vacuum degree of the vacuum reaction chamber is 5 Pa. The ETFE membrane moves at a speed of 3 m / min. Example

[0046] The difference from Example 6 is that the aluminum methacrylate delivery flow rate is 1 sccm, the oxygen delivery flow rate is 20 sccm, the radio frequency power is 500 W when generating the Al2O3 coating, and the vacuum degree of the vacuum reaction chamber is 5 Pa. The ETFE membrane moves at a speed of 5 m / min.

[0047] Comparative Example 1

[0048] The difference from Example 1 is that the aluminum methacrylate delivery flow rate is 2 sccm, the oxygen delivery flow rate is 21 sccm, the vacuum degree of the vacuum reaction chamber is 6 Pa, the radio frequency power when forming Al2O3 is 550 W, and the heating temperature of the ETFE membrane is 85°C.

[0049] Comparative Example 2

[0050] The difference from the comparative example is that the heating temperature of the ETFE membrane is 48°C.

[0051] The chemical compositions of the above examples and comparative examples were tested using XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier transform infrared spectroscopy). In Examples 1 to 7, the Al 2p peak was located at 74.5 eV, the O 1s peak was located at 531 eV, the O / Al atomic ratio was approximately 1.5, and the carbon residue in Examples 2 to 4 was less than 5 at.%, while the carbon residue in Examples 1, 5 to 7 was between 6 at.% and 7 at.%. In Comparative Examples 1 to 2, the O / Al atomic ratio was approximately 1.2, and the carbon residue was greater than 7 at.%.

[0052] The physical properties of the above examples and comparative examples were tested using AFM (Atomic Force Microscopy) and an ellipsometer. In Examples 2-4, the surface roughness Ra of the coatings was less than 5 nm, indicating a dense, non-porous coating. In Examples 1, 5-7, the surface roughness Ra of the coatings was between 6 nm and 8 nm. In Comparative Examples 1-2, the surface roughness Ra of the coatings was greater than 10 nm. The thickness uniformity of the coatings in Examples 2-4 was ±5%, in Examples 1, 5-7 it was ±7%, and in Comparative Examples 1-2 it was ±10%. The refractive index of Examples 1-7 was 1.65–1.70, and in Comparative Examples 1-2 it was 1.5–1.55.

[0053] The barrier properties of the products were characterized by WVTR (water vapor transmission rate, test conditions 38°C, 90% RH (humidity)) and OTR (oxygen transmission rate, test conditions 23°C, 0% RH (humidity)). In Examples 2-4, the water vapor transmission rate of the products was less than 1 g / m² / day, and the oxygen transmission rate was less than 1 cm³ / m² / day. In Examples 1, 5-7, the water vapor transmission rate of the products was between 1 g / m² / day and 2 g / m² / day, and the oxygen transmission rate was between 1 cm³ / m² / day and 3 cm³ / m² / day. In Comparative Examples 1 and 2, the water vapor transmission rate was greater than 5 g / m² / day, and the oxygen transmission rate was greater than 6 cm³ / m² / day.

[0054] In addition, chemical resistance tests were conducted on the products of the above examples and comparative examples. On one hand, the products were immersed in a pH 2–12 solution for 24 hours to observe whether the coating corroded or peeled off. On the other hand, the contact angle changes were measured after wiping with acetone and ethanol. The products in Examples 1–7 showed no corrosion or peeling, while the products in Comparative Examples 1–2 showed partial corrosion and peeling. After wiping with organic solvents, the contact angle changes of the products in Examples 1–7 were less than 5°. The contact angle changes of the products in Comparative Examples 1–2 were greater than 5°.

[0055] The mechanical properties of the above examples and comparative examples were tested according to standards 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 radius of curvature of 5 mm, and showed no cracks after 1000 cycles. The products in Comparative Examples 1 and 2 had a critical load less than 4 N, a radius of curvature of 5 mm, and showed cracks after 500 cycles.

[0056] In this application, the coordination of various process parameters enables the Al2O3-containing ETFE membrane to exhibit advantages such as better thickness uniformity, lower roughness, and fewer byproducts, thereby resulting in a product with better barrier properties, chemical resistance, and mechanical properties. Furthermore, by coordinating the flow rate with RF power, post-processing steps, pre-processing steps, and vacuum levels, an alumina coating can be formed on the surface of the ETFE membrane at an environment of 50–80°C, thus helping to prevent thermal damage to the ETFE membrane substrate.

[0057] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for plasma vapor deposition of aluminum oxide, characterized in that, Includes the following steps: The ETFE membrane is fed into the pretreatment zone of the vacuum reaction chamber, where it is then subjected to plasma cleaning and activation. The cleaned ETFE membrane is transferred to the deposition zone of the vacuum reaction chamber and heated at a temperature of 50–80°C. Aluminum methacrylate is injected into an evaporator to vaporize. Oxygen is mixed with the aluminum methacrylate vapor and then injected into the deposition zone together. An inert gas is injected into the deposition zone as a carrier gas. The flow rate of aluminum methacrylate is 0.2–0.5 sccm, and the flow rate of oxygen is 10–15 sccm. The radio frequency power supply is turned on to excite plasma in the deposition region, so that Al2O3 is generated on the surface of the ETFE film, with a radio frequency power of 100–300 W. The ETFE membrane that generates Al2O3 is transferred to the post-processing area of ​​the vacuum reaction chamber for oxygen plasma annealing 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. The ETFE membrane is transported by a roll-to-roll process at a speed of 0.5-2 m / min.

2. The method as described in claim 1, characterized in that, Also includes: The ETFE film, which forms an Al2O3 layer outside the vacuum reaction chamber, is cooled to room temperature by a cooling roller and then wound up.

3. The method as described in claim 1, characterized in that, The radio frequency power of the pretreatment area is 50 W, and the cleaning and activation time is 1–5 minutes.

4. The method as described in claim 1, characterized in that, The vacuum level of the vacuum reaction chamber is 0.1-1 Pa.

5. The method as described in claim 1, characterized in that, The vaporization temperature of the aluminum methacrylate is 80–120°C.

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