Sealing solution as well as preparation method and application thereof

Abstract

The invention relates to a sealing solution and a preparation method and application thereof, and relates to the technical field of anodic oxidation. The invention provides a preparation method of a sealing solution, which comprises the following steps: (1) mixing a fluotitanic acid solution, a zirconium fluoride solution, a glycerol solution, a sodium metaphosphate solution and water to obtain a stock solution; and (2) adding pure water into the stock solution, and uniformly stirring to obtain a closed solution. When the prepared sealing solution is used for preparing a part oxide layer, a surface film layer with ultrahigh sealing performance and excellent corrosion resistance can be obtained, the vacuum leak rate of the surface film layer is as low as 10-12 Pa.L / s, the corrosion-resistant hydrochloric acid Bubble test exceeds 4 h, and the requirements for ultrahigh sealing performance and excellent corrosion resistance are met.

Description

Technical Field

[0001] This invention relates to the field of anodizing technology, specifically to a sealed solution, its preparation method, and its application. Background Technology

[0002] In semiconductor photolithography, an ultra-high vacuum environment must be maintained, and corrosive gases are involved. Many components require extremely high sealing performance and excellent corrosion resistance. Normal aluminum alloy surfaces cannot meet the corrosion resistance requirements and must be anodized. However, the microscopic cracks, porous structure, and wrinkles that exist in normal anodized films cannot meet the requirements for ultra-high vacuum sealing. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide a sealing solution, its preparation method, and its application. This invention provides a sealing solution, its preparation method, and its application, which, when used in the preparation of oxide layers on parts, can yield a surface film with ultra-high sealing performance and excellent corrosion resistance, achieving a vacuum leakage rate as low as 10%. -12 Pa·L / s, with a hydrochloric acid Bubble test exceeding 8 hours, meeting the requirements for ultra-high sealing performance and excellent corrosion resistance.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: The first objective of this invention is to provide a method for preparing a closed solution, comprising the following steps: (1) Mix fluorotitanic acid solution, zirconium fluoride solution, glycerol solution, sodium metaphosphate solution and water to obtain the stock solution; (2) Add pure water to the original solution and stir evenly to obtain a closed solution.

[0005] The beneficial effects of this invention are: glycerol has a corrosion-inhibiting effect; fluorozirconic acid preferentially reduces high points under the microscopic film layer, which can level the microscopic oxide layer and further improve the sealing effect; zirconium fluoride provides excellent sealing properties, significantly improving the sealing rate and corrosion resistance of the film layer. Using the sealing solution prepared by this invention, there is no need to grind the sealing surface after anodizing, which can significantly shorten the process time, reduce costs, and decrease rework rate.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, in step (1), the concentration of fluorotitanic acid is 7 g / L to 9 g / L, the concentration of zirconium fluoride is 3 g / L to 6 g / L, the concentration of glycerol is 18 g / L to 21 g / L, and the concentration of sodium metaphosphate is 1 g / L to 3 g / L.

[0008] Furthermore, the concentration of the original solution in the sealed solution is 1 g / L to 2 g / L.

[0009] Furthermore, if the pH is high, use the original solution to lower the pH value; if the pH value is low, use ammonia to raise the pH value. If the aluminum ion content in the sealing solution is <0.5g, it should be discarded, or if the usage time exceeds 1 month, it should be discarded.

[0010] A second objective of this invention is to provide a closed solution.

[0011] The beneficial effects of this invention are: the sealing solution of this invention can not only seal the oxide film, but also level the oxide film to meet the sealing requirements.

[0012] Furthermore, the pH of the sealing solution is 3-4.

[0013] A third objective of this invention is to provide an application of a sealing solution, which is used in the preparation of an oxide layer on a part.

[0014] The fourth objective of this invention is to provide a method for preparing an oxide layer on a part, the method being as follows: The parts are anodized to obtain parts with an oxide film on the surface. The parts with an oxide film on the surface are then placed in a sealed solution for sealing. Finally, they are taken out and dried to obtain parts with an oxide layer attached.

[0015] The beneficial effects of this invention are: improving the corrosion resistance of the part surface through surface anodizing, allowing it to operate in the corrosive gas environment of photolithography; subsequent sealing yields a surface film with ultra-high sealing performance and excellent corrosion resistance, with a vacuum leakage rate as low as 10%. -12 Pa·L / s, with a hydrochloric acid Bubble test exceeding 8 hours, meeting the requirements for ultra-high sealing performance and excellent corrosion resistance.

[0016] Furthermore, the sealing area of ​​the part should have Ra < 0.2um; otherwise, the sealing surface needs to be ground. If there is a special structure that is not easy to seal, grinding is not required, but the machining lines must be aligned with the grain and Ra < 0.2um.

[0017] Furthermore, the anodizing is performed by immersing the parts in an oxalic acid solution and applying an electric current; the concentration of the oxalic acid solution is 40 g / L to 50 g / L; and the temperature is 13°C to 17°C.

[0018] The beneficial effects of adopting the above-mentioned further scheme are: the oxide layer of the oxalic acid anode has strong corrosion resistance and small micropores, and its hydrochloric acid Bubble test can easily exceed 4 hours. This oxide layer can meet the stability requirements for use in photolithographic corrosive environments.

[0019] Furthermore, the gradient current used for the anodizing is 0.5 A / dm. 2 ~1A / dm 2 The thickness of the oxide film is 15um to 25um.

[0020] Furthermore, during anodizing, first use 0.5 A / dm 2 Oxidation at a current density of 1 A / dm for 30 min, then at 1 A / dm 2 Oxidize at a current density for 40-60 minutes, with the specific time depending on achieving the target film thickness.

[0021] The beneficial effects of adopting the above-mentioned further solution are: the oxide layer of the oxalic acid anode has excellent elasticity, which is more suitable for sealing requirements; the lower current in the process can significantly reduce the generation of surface wrinkles and porosity, and further improve the sealing effect.

[0022] Furthermore, the sealing temperature is 80℃~90℃, and the sealing time is 3h~4h.

[0023] Furthermore, the drying temperature is 70℃~80℃, and the time is 20min~30min. Detailed Implementation

[0024] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0025] Example 1: Preparation of the blocking solution (1) Take 8 g / L of fluorotitanic acid, 5 g / L of zirconium fluoride, 20 g / L of glycerol, 2 g / L of sodium metaphosphate, and the remainder of deionized water, and mix them together to obtain a stock solution of 1~2 g / L. (2) Use pure water to build a bath for the stock solution with a concentration of 1g / L~2g / L, stir evenly, and obtain a closed solution with a pH of 3~4.

[0026] Example 2: Preparation of oxide layer on part (1) Parts with a sealed area Ra<0.2um were placed in a neutral degreasing solution for degreasing, then rinsed with overflow water for 2.5min. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were removed and chemically polished for 45s in an aluminum alloy chemical solution (Sifcoasc) at 93℃. Then, the parts were rinsed with overflow water for 2.5min. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were de-dusted with 25% w / w nitric acid at room temperature for 4min with bubble agitation. The overflow water rinse was performed twice more, 2.5min each time. Then, the surface of the parts after water rinsing was sprayed with pure water and placed in an oxalic acid solution (pure water bath) at 15℃ with a concentration of 40g / L for anodizing at 0.5A / dm. 2Oxidation at a current density of 30 min, followed by oxidation at 1 A / dm 2 The current density was then increased for 40-60 minutes to obtain a part with an oxide film thickness of 20 μm. (2) The parts with an oxide film thickness of 20 μm were rinsed twice with pure water for 2.5 min each time. During the water rinsing, air was circulated to stir the bubbles. The parts were then immersed in a sealing solution at 85°C and pH 3.5 for 3.5 h. After sealing, the parts were taken out and rinsed with pure water for 2.5 min. During the water rinsing, air was circulated to stir the bubbles. After the water rinsing, the surface was sprayed with pure water again. Finally, the surface moisture was dried with CDA and dried at 75°C for 30 min to obtain the parts with an oxide layer.

[0027] Example 3: Preparation of the oxide layer on the part (II) (1) Parts with a sealed area Ra<0.2um were placed in a neutral degreasing solution for degreasing, then rinsed with overflow water for 2 minutes. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were removed and chemically polished for 30 seconds in an aluminum alloy chemical solution (Sifcoasc) at 90℃. Then, the parts were rinsed with overflow water for 2 minutes. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were de-dusted with 20% w / w nitric acid at room temperature for 3 minutes with bubble agitation. The parts were then rinsed with overflow water twice, 2 minutes each time. After that, the surface of the parts was sprayed with pure water and then placed in an oxalic acid solution (pure water bath) at 13℃ with a concentration of 40g / L for anodizing at 0.5A / dm. 2 Oxidation at a current density of 30 min, followed by oxidation at 1 A / dm 2 The current density was then increased for 40-60 minutes to obtain a part with an oxide film thickness of 15 μm. (2) The part with an oxide film thickness of 15 μm was rinsed twice with pure water for 2 min each time. During the water rinsing, air was circulated to stir the bubbles. Then the part was immersed in the sealing solution prepared in Example 1 at 80°C and pH 3 for 3 h for sealing. After sealing, the part was taken out and rinsed with overflow water for 2 min. During the water rinsing, air was circulated to stir the bubbles. After the water rinsing, the surface was sprayed with pure water again. Finally, the surface moisture was dried with CDA and dried at 70°C for 30 min to obtain the part with an oxide layer.

[0028] Example 4: Preparation of the oxide layer on the part (Part 3) (1) Parts with sealed areas Ra<0.2um were placed in a neutral degreasing solution for degreasing, then rinsed with overflow water for 3 minutes. During the water rinse, air was ventilated for bubble agitation. After the water rinse, the parts were removed and chemically polished for 60 seconds in an aluminum alloy chemical solution (Sifcoasc) at 95°C. Then, the parts were rinsed with overflow water for 3 minutes. During the water rinse, air was ventilated for bubble agitation. After the water rinse, the parts were de-dusted with 30% w / w nitric acid at room temperature for 5 minutes with bubble agitation. The parts were then rinsed with overflow water twice, 3 minutes each time. After that, the surface of the parts was sprayed with pure water and then placed in an oxalic acid solution (pure water bath) at 17°C with a concentration of 40 g / L for anodizing at 0.5 A / dm. 2 Oxidation at a current density of 30 min, followed by oxidation at 1 A / dm 2 The current density was then increased for 40-60 minutes to obtain a part with an oxide film thickness of 25 μm. (2) The parts with an oxide film thickness of 25 μm were rinsed twice with pure water for 3 min each time. During the water rinsing, air was circulated to stir the bubbles. The parts were then immersed in a sealing solution at 90℃ and pH 4 for 4 h. After sealing, the parts were taken out and rinsed with pure water for 3 min each time. During the water rinsing, air was circulated to stir the bubbles. After the water rinsing, the surface was sprayed with pure water again. Finally, the surface moisture was dried with CDA and dried at 80℃ for 30 min to obtain the parts with an oxide layer.

[0029] Comparative Example 1: Preparation of oxide layer on part (1) Parts with a sealed area Ra<0.2um were placed in a neutral degreasing solution for degreasing, then rinsed with overflow water for 2.5min. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were removed and chemically polished for 45s in an aluminum alloy chemical solution (Sifcoasc) at 93℃. Then, the parts were rinsed with overflow water for 2.5min. During the water rinse, air was circulated for bubble agitation. After the water rinse, the parts were de-dusted with 25% w / w nitric acid at room temperature for 4min with bubble agitation. The overflow water rinse was performed twice more, 2.5min each time. Then, the surface of the parts after water rinsing was sprayed with pure water and placed in an oxalic acid solution (pure water bath) at 15℃ with a concentration of 40g / L for anodizing at 0.5A / dm. 2 Oxidation at a current density of 30 min, followed by oxidation at 1 A / dm 2 The current density was then increased for 40-60 minutes to obtain a part with an oxide film thickness of 20 μm. (2) The parts with an oxide film thickness of 20 μm were rinsed twice with pure water for 2.5 min each time. During the water rinsing, air was circulated to agitate the bubbles. The parts were then placed in pure water at 95~100℃ and sealed for 2~3 h. After sealing, the parts were taken out and rinsed with pure water for 2.5 min. During the water rinsing, air was circulated to agitate the bubbles. After the water rinsing was completed, the surface was sprayed with pure water again. Finally, the surface moisture was dried with CDA and dried at 75℃ for 30 min to obtain the parts with an oxide layer.

[0030] Comparative Example 2: Preparation of Oxide Layer on Parts Parts with a sealed area Ra < 0.2 μm were degreased in a neutral degreasing solution, then rinsed with overflow water for 2 minutes, with aeration and bubble agitation during rinsing. After rinsing, the parts were chemically polished for 30 seconds in an aluminum alloy chemical solution (Sifcoasc) at 90°C, followed by rinsing with overflow water for 2 minutes, with aeration and bubble agitation during rinsing. After rinsing, the parts were degreased with 20% w / w nitric acid at room temperature for 3 minutes, with bubble agitation, and then rinsed with overflow water twice more, 2 minutes each time. The surface of the rinsed parts was then sprayed with pure water and anodized in a 40 g / L oxalic acid solution (pure water bath) at 13°C at 0.5 A / dm². 2 Oxidation at a current density of 30 min, followed by oxidation at 1 A / dm 2 The current density was then increased for 40-60 minutes to obtain a part with an oxide film thickness of 15 μm. (2) The part with an oxide film thickness of 15 μm was rinsed twice with pure water for 2 min each time. During the water rinsing, air was circulated to stir the bubbles. Then the part was immersed in the sealing solution prepared in Example 1 at 80°C and pH 3 for 6 h for sealing. After sealing, the part was taken out and rinsed with overflow water for 2 min. During the water rinsing, air was circulated to stir the bubbles. After the water rinsing, the surface was sprayed with pure water again. Finally, the surface moisture was dried with CDA and dried at 70°C for 30 min to obtain the part with an oxide layer.

[0031] Performance testing: (1) Helium test: The vacuum leakage rate of the oxide-coated parts of Examples 2-4 and Comparative Examples 1-2 was measured using a helium analyzer (Infricon, Germany); (2) Corrosion-resistant hydrochloric acid Bubble test: A glass tube with a diameter of 15-20 mm was glued to the surface of the oxide-coated parts of Examples 2-4 and Comparative Examples 1-2 with waterproof adhesive. 5% WT hydrochloric acid was injected into the tube to a height of 10-20 mm. The surface of the oxide layer in contact with the hydrochloric acid at the bottom of the tube was observed (observed at least once every 10 minutes). The experiment was terminated when three bubbles were released continuously from the same point. The hydrochloric acid immersion time was recorded. The results are shown in Table 1. Table 1 From Table 1, we can obtain: The sealing solution prepared by the method of this invention, when used in the preparation of oxide layers on parts, can produce a surface film with ultra-high sealing performance and excellent corrosion resistance, with a vacuum leakage rate as low as 10%. -12 Pa·L / s, with a hydrochloric acid Bubble test exceeding 4 hours, meeting the requirements for ultra-high sealing performance and excellent corrosion resistance.

[0032] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a blocked solution, characterized in that, Includes the following steps: (1) Mix fluorotitanic acid solution, zirconium fluoride solution, glycerol solution, sodium metaphosphate solution and water to obtain the stock solution; (2) Add pure water to the original solution and stir evenly to obtain a closed solution.

2. The method for preparing a blocking solution according to claim 1, characterized in that, The concentration of fluorotitanic acid in step (1) is 7 g / L to 9 g / L, the concentration of zirconium fluoride is 3 g / L to 6 g / L, the concentration of glycerol is 18 g / L to 21 g / L, and the concentration of sodium metaphosphate is 1 g / L to 3 g / L.

3. The method for preparing a blocking solution according to claim 2, characterized in that, The concentration of the original solution in the sealed solution is 1 g / L to 2 g / L.

4. A sealed solution, characterized in that, The sealing solution is prepared by the preparation method according to any one of claims 1 to 3.

5. An application of a closed solution, characterized in that, The sealing solution described in claim 4 is used in the preparation of the oxide layer on the part.

6. A method for preparing an oxide layer on a component, characterized in that, The specific preparation method is as follows: The parts are anodized to obtain parts with an oxide film on the surface. The parts with an oxide film on the surface are then placed in the sealing solution as described in claim 4 for sealing. Finally, they are taken out and dried to obtain parts with an oxide layer attached.

7. The method for preparing an oxide layer on a part according to claim 6, characterized in that, The anodizing process involves immersing the parts in an oxalic acid solution and applying an electric current to perform anodizing; the concentration of the oxalic acid solution is 40 g / L to 50 g / L; and the temperature is 13°C to 17°C.

8. The method for preparing an oxide layer on a part according to claim 6, characterized in that, The gradient current used for the anodic oxidation is 0.5 A / dm. 2 ~1A / dm 2 The thickness of the oxide film is 15um to 25um.

9. The method for preparing an oxide layer on a part according to claim 6, characterized in that, The sealing temperature is 80℃~90℃, and the time is 3h~4h.

10. The method for preparing an oxide layer on a part according to claim 6, characterized in that, The drying temperature is 70℃~80℃, and the time is 20min~30min.

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