Post-treatment method for perfluorinated sealing rings

Abstract

The application discloses a kind of post-processing methods of perfluorinated sealing ring, steps are as follows: S01: preparation perfluorinated sealing ring;S02: the perfluorinated sealing ring prepared is placed in hydrofluoric acid solution and is soaked;S03: the perfluorinated sealing ring after soaking is taken out, dry, again be placed in isopropanol solution and soak;S04: the perfluorinated sealing ring after soaking is taken out from isopropanol solution, and isopropanol solution is titrated sample;The perfluorinated sealing ring post-processing method described in the application, the perfluorinated sealing ring after being treated by the method can effectively reduce the metal cation contained in product;In semiconductor and liquid crystal display industry, the method can effectively improve the quality of wafer in wet etching, and the method is simple and convenient to operate, and only by solution soaking can good treatment effect be achieved, and it is economic and efficient.

Description

Technical Field

[0001] This invention relates to the field of sealing ring technology, specifically to a post-processing method for perfluorinated sealing rings. Background Technology

[0002] Existing perfluorinated seal products require cleaning after two-stage vulcanization. Current cleaning methods only involve ultrasonic surface cleaning in deionized water, which can remove surface contaminants but does not remove metal cations within the seal, thus failing to reduce the total amount of metal cations in the product. In the semiconductor and LCD industries, the dissolved metal cations affect wafer quality during wet etching, severely impacting yield. Consequently, frequent replacements lead to high equipment maintenance costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a post-treatment method for perfluorinated sealing rings, which solves the problem of high usage cost caused by the high metal cation content in perfluorinated sealing rings.

[0004] The present invention is achieved through the following technical solution.

[0005] The present invention provides a post-treatment method for a perfluorinated sealing ring, comprising the following steps:

[0006] S01: Preparation of perfluorinated sealing rings;

[0007] S02: Immerse the prepared perfluorinated sealing ring in a hydrofluoric acid solution;

[0008] S03: Remove the soaked perfluorinated sealing ring, dry it, and then soak it again in the isopropanol solution;

[0009] S04: Remove the soaked perfluorinated sealing ring from the isopropanol solution and titrate the isopropanol solution to determine the sample.

[0010] Furthermore, in step S01 above, the perfluoroelastomer is prepared by mixing and vulcanizing perfluoroether rubber, organic peroxide, and triallyl isocyanate as raw materials, and then preparing the perfluoroether rubber ring after vulcanization.

[0011] Furthermore, in step S02 above, the hydrofluoric acid solution is a 50% concentration hydrofluoric acid solution.

[0012] Furthermore, in step S02 above, the immersion conditions of the perfluorinated sealing ring in hydrofluoric acid solution are: immersion at 25°C for 4 hours, and vibration cleaning during immersion.

[0013] Furthermore, in step S03 above, the isopropanol solution is a 50% concentration isopropanol solution.

[0014] Furthermore, in step S03 above, the conditions for immersing the perfluorinated sealing ring in the isopropanol solution are: immersion at 25°C for 24 hours.

[0015] Furthermore, in step S04 above, after titration of the sample, the content of metal cations is tested using an analyzer.

[0016] The beneficial effects of the present invention are as follows: The post-treatment method for perfluorinated sealing rings described in this invention can effectively reduce the metal cations contained in the product after treatment by the perfluorinated sealing rings. In the semiconductor and liquid crystal display industries, this method can effectively improve the quality of wafers in wet etching. Moreover, this method is simple and convenient to operate, and only requires immersion in a solution to achieve good treatment results, which is economical and efficient. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating an embodiment of the present invention. Detailed Implementation

[0019] under Figure 1 The present invention will be described in detail below;

[0020] The post-treatment method for a perfluorinated sealing ring described in this application includes the following steps:

[0021] S01: Preparation of perfluorinated sealing rings;

[0022] S02: Immerse the prepared perfluorinated sealing ring in a hydrofluoric acid solution;

[0023] S03: Remove the soaked perfluorinated sealing ring, dry it, and then soak it again in the isopropanol solution;

[0024] S04: Remove the soaked perfluorinated sealing ring from the isopropanol solution and titrate the isopropanol solution to determine the sample.

[0025] In step S01 above, the perfluoroelastomer ring is prepared by mixing and vulcanizing perfluoroether rubber, organic peroxide, and triallyl isocyanate as raw materials.

[0026] The most common type of perfluoroether rubber ring prepared is the 214# perfluoroether sealing ring in American standard AS568. The manufacturing process is as follows:

[0027] 100 parts by weight of perfluoroether rubber, preferably "PM-3500" manufactured by AGC, are selected; 0.75 parts by weight of organic peroxide, preferably "Double 25" manufactured by Arkema; ​​and 0.5 parts by weight of triallyl isocyanurate, preferably TAI C manufactured by Arkema. The mixtures are uniformly mixed using a two-roll mill, and then vulcanized at 165°C for 20 minutes for the first vulcanization. A 50T flatbed vulcanizing mill is conventionally used for the first vulcanization; 50T is the equipment model, but other models can be used. A second vulcanization is then performed at 250°C in a nitrogen-filled oven or other secondary vulcanization oven that achieves the same vulcanization requirements for 16 hours. The resulting perfluoroether rubber ring is designated as 0-Ri. ng product #214 (CS: 3.53mm, ID: 24.99mm), where CS: 3.53mm and ID: 24.99mm represent an O-ring with a wire diameter of 3.53mm and an inner diameter of 24.99mm.

[0028] In step S02 above, the hydrofluoric acid solution is a 50% concentration hydrofluoric acid solution.

[0029] In step S02 above, the perfluorinated sealing ring is immersed in hydrofluoric acid solution under the following conditions: immersion at 25°C for 4 hours, with vibration cleaning performed during immersion.

[0030] In step S03 above, the isopropanol solution is a 50% isopropanol solution.

[0031] In step S03 above, the conditions for immersing the perfluorinated sealing ring in isopropanol solution are: immersion at 25°C for 24 hours.

[0032] In step S04 above, after titration of the sample, the content of metal cations is tested using an analyzer. The analyzer is preferably an inductively coupled plasma mass spectrometer (ICP-MS) to test the content of metal cations in the isopropanol solution that has been soaked in a perfluorinated sealing ring.

[0033] The principle behind treating perfluoroelastomer seals using the above method is as follows: Soaking them in hydrofluoric acid helps to remove metal cations from the rubber product. Hydrofluoric acid has strong penetrating power, allowing it to penetrate deep into the rubber and effectively remove the metal cations. Metal cations (such as calcium, potassium, sodium, iron, and copper) in perfluoroelastomer seals can dissolve in hydrofluoric acid, thus reducing the metal content of the seals after cleaning.

[0034] The purpose of immersing the product in isopropanol is to dissolve residual metal cations in the rubber product. Therefore, after pickling with hydrofluoric acid, further cleaning with isopropanol solution can further remove residual metal cations in the perfluorinated seal.

[0035] When performing titration, nitric acid is added to the isopropanol solution to perform the titration, which facilitates the use of inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentration of metal cations.

[0036] Example 1: Following the post-treatment steps of the perfluoroelastomer sealing ring, a perfluoroelastomer rubber ring was first prepared. Then, the prepared perfluoroelastomer rubber ring was cleaned in a hydrofluoric acid solution, dried, and then placed in an isopropanol solution. Nitric acid was added for titration, and the total metal cations were tested using ICP-MS. The specific implementation method is as follows:

[0037] 100 parts by weight of perfluoroether rubber ("PM-3500", manufactured by AGC), 0.75 parts by weight of organic peroxide ("Bis-25", manufactured by Arkema), and 0.5 parts by weight of triallyl isocyanate (TAIC C, manufactured by Arkema) were uniformly mixed using a two-roll mill. The mixture was then vulcanized at 165°C for 20 min for the first vulcanization, followed by a second vulcanization at 250°C in a nitrogen-filled oven for 16 h. O-Ri ng product #214 (CS: 3.53 mm, ID: 24.99 mm) was prepared. The prepared sample was washed with hydrofluoric acid at 25°C for 4 h using vibration. After drying, the sample was digested in 50% isopropanol solution at 25°C for 24 h. The digested isopropanol solution was titrated with nitric acid, and the total metal cations were measured using inductively coupled plasma mass spectrometry (ICP-MS). The test results are shown in Table 1 below.

[0038] Comparative Example 1, as a post-treatment method for conventional perfluoroelastomer (PF) sealing rings, involves the same preparation process as Example 1. The difference lies in that the prepared PF sealing ring is immersed in pure water and cleaned under the same conditions. The steps and conditions are identical, serving as a reference for comparison with Example 1. First, a perfluoroether rubber ring is prepared. Then, the prepared perfluoroether rubber ring is cleaned in pure water, dried, and then placed in an isopropanol solution. After titration with nitric acid, the total amount of metal cations is measured using ICP-MS. The specific implementation method is as follows:

[0039] 100 parts by weight of perfluoroether rubber ("PM-3500", manufactured by AGC), 0.75 parts by weight of organic peroxide ("Bis-25", manufactured by Arkema), and 0.5 parts by weight of triallyl isocyanate (TAIC, manufactured by Arkema) were uniformly mixed using a two-roll mill. The mixture was then vulcanized at 165°C for 20 min for the first vulcanization, followed by a second vulcanization at 250°C in a nitrogen-filled oven for 16 h. O-Ring product #214 (CS: 3.53 mm, ID: 24.99 mm) was prepared. The prepared sample was washed with pure water at 25°C for 4 h using vibration. After drying, the washed sealing ring was digested in 50% isopropanol solution at 25°C for 24 h. The digested isopropanol solution was titrated with nitric acid, and the total metal cations were measured using ICP-MS. The test results are shown in Table 1 below.

[0040] Example 1 6.204 Comparative Example 1 38.472

[0041] Table 1

[0042] As shown in Table 1, if pure water is used to clean rubber products, only the surface of the product can be cleaned, and the metal ions inside the product cannot be removed. However, the total amount of metal cations in the perfluoroelastomers treated by the post-treatment method disclosed in this application is significantly reduced, making them more suitable for the semiconductor and liquid crystal display industries. Using perfluoroelastomers treated by this method can effectively improve the quality of wafers in wet etching, reduce the replacement frequency of perfluoroelastomers, and reduce the usage cost in production and manufacturing.

[0043] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand and implement the present invention. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A post-treatment method for perfluorinated sealing rings, characterized in that: S01: Preparation of perfluorinated sealing rings; S02: Immerse the prepared perfluorinated sealing ring in a hydrofluoric acid solution; S03: Remove the soaked perfluorinated sealing ring, dry it, and then soak it again in the isopropanol solution; S04: Remove the soaked perfluorinated sealing ring from the isopropanol solution and titrate the isopropanol solution to determine the sample. In step S01 above, the perfluoro seal ring is prepared by mixing and vulcanizing perfluoroether rubber, organic peroxide and triallyl isocyanate as raw materials. In step S02 above, the perfluorinated sealing ring is immersed in hydrofluoric acid solution under the following conditions: immersion at 25°C for 4 hours, with vibration cleaning during immersion; the hydrofluoric acid solution is a 50% concentration hydrofluoric acid solution. In step S03 above, the isopropanol solution is a 50% concentration isopropanol solution; In step S03 above, the conditions for immersing the perfluorinated sealing ring in isopropanol solution are: immersion at 25°C for 24 hours; In step S04 above, after titration of the sample, the content of metal cations is tested using an analyzer, and the concentration of metal cations is tested using an inductively coupled plasma mass spectrometer (ICP-MS).

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