Metal plate frame and fluororubber sealing assembly and preparation method thereof

Abstract

The invention provides a metal plate frame and fluororubber sealing assembly and a preparation method thereof, and the preparation method is applied to the technical field of semiconductor sealing and comprises the steps that S1, a metal plate frame is coated with an adhesive, dried and then cooled, and the adhesive is a trithiocyanuric acid derivative solution; s2, a cross-linking agent and an addition agent are added in the thin-passing mixing process of the perfluoroether elastomer, a mixed rubber compound is obtained, the addition agent comprises fluorinated silicon dioxide, fluorinated titanium dioxide or PFA micro powder, and the mass of the addition agent is 2-10% of the mass of the perfluoroether elastomer; and S3, the mixed rubber sheet is placed in a metal plate frame, the metal plate frame with the mixed rubber sheet is placed in a mold to be subjected to hot pressing vulcanization forming, then secondary vulcanization is conducted, then radiation vulcanization is conducted, and the assembly is obtained. The assembly prepared through the method is resistant to plasma etching and high in cleanliness, the bonding performance of the perfluoroether rubber and the metal plate frame is good, and the rate of finished products is high.

Description

Technical Field

[0001] This application relates to the field of semiconductor sealing technology, specifically to a metal plate frame and fluororubber sealing assembly and its preparation method. Background Technology

[0002] Semiconductor fabrication utilizes various sealed cleanrooms designed to prevent contaminants that could affect the quality of the final products, such as semiconductor wafers and chips. These chambers include gates and valves, such as slit valves, to isolate the chamber from the surrounding environment. These gates typically consist of a metal frame and sealing gaskets cross-linked to the frame. The materials used to fabricate these gaskets are usually made of fluoropolymers or fluoropolymers, and in some cases, perfluoroether rubber for highly contamination-resistant seals. These gates are commonly used in process reaction chambers during semiconductor fabrication to open and close the chamber.

[0003] Perfluoroelastomer (FFKM) materials possess chemical resistance, plasma resistance, and acceptable compression set and mechanical properties. Therefore, FFKM materials have a wide range of applications. FFKM is typically prepared from perfluorinated monomers, including at least one monomer with a vulcanization point, which polymerizes to form a perfluoroelastomer containing vulcanization sites. A typical FFKM rubber composition includes the aforementioned perfluoroelastomer, a crosslinking agent, and the desired filler.

[0004] The inertness of perfluoroether rubber compositions offers advantages for use in harsh and clean environments, but due to their low surface energy, it is difficult to achieve sufficient strength and durability when bonded to metal plate and frame surfaces with higher surface energy.

[0005] Therefore, a new technological solution is needed. Summary of the Invention

[0006] In view of this, embodiments of this specification provide a method for preparing a metal plate frame and perfluoroether rubber sealing assembly to improve the adhesion performance between the perfluoroether rubber and the metal plate frame.

[0007] This specification provides the following technical solution: a method for preparing a metal plate frame and fluororubber sealing assembly, comprising: S1. Apply an adhesive to the bonding area between the metal plate frame and the perfluoroether rubber, dry and cool it. The adhesive is a trithiocyanate derivative solution. S2. A crosslinking agent and filler are added to the perfluoroether elastomer during the thin-pass compounding process to obtain a compound. The filler includes fluorinated silica, fluorinated titanium dioxide, or PFA micro powder. The mass of the filler is 2-10 wt% of the mass of the perfluoroether elastomer. The perfluoroether elastomer uses a perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) containing a nitrile group as its vulcanizing point monomer. The vulcanizing point monomer is 1.5-3 wt% of the mass of the perfluoroether elastomer. S3. Place the mixed rubber sheet inside a metal frame, place the metal frame with the mixed rubber sheet inside a mold for hot pressing and vulcanization, remove the metal frame, clean the burrs, perform secondary vulcanization, and then perform radiation vulcanization to obtain the assembly.

[0008] Optionally, in S1, the metal plate is coated after undergoing mechanical treatment, solvent cleaning and degreasing, and plasma treatment in sequence. The mechanical treatment includes sanding and sandblasting.

[0009] Optionally, the metal frame is made of aluminum-magnesium alloy 6061.

[0010] Optionally, in S1, the solution concentration of the trithiocyanate derivative is 2-6 wt%.

[0011] Optionally, in S1, the trithiocyanate derivative is a monosodium trithiocyanate salt.

[0012] Optionally, in S1, the solvent in the trithiocyanate derivative solution is ethanol, methanol, or isopropanol.

[0013] Optionally, in S1, the drying temperature is 50-100 ℃ and the drying time is 8-15 min.

[0014] Optionally, in S2, the crosslinking agent is tetraphenyltin or hexaoxane, wherein the tetraphenyltin is 0.3-0.5 wt% of the mass of the perfluoroether elastomer, and the hexaoxane is 0.5-1 wt% of the mass of the perfluoroether elastomer.

[0015] Optionally, in S3, the hot-press vulcanization molding conditions are 140-160 ℃ × 10-20 min.

[0016] Optionally, in S3, the vulcanization conditions for the secondary vulcanization are 180-220 ℃ × 4-12 hr.

[0017] Optionally, in S3, the radiation dose of the radiation sulfurization is 30-100 kGy.

[0018] This application also provides a metal plate frame and fluororubber sealing assembly, which is prepared by the preparation method described above.

[0019] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: The preparation method of this application improves the adhesion performance of perfluoroether rubber to metal plate frame and the yield of sealing assembly under high-cleanliness plasma etching conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the method of this application. Detailed Implementation

[0022] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0023] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0025] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0026] Semiconductor fabrication utilizes various sealed cleanrooms designed to prevent contaminants that could affect the quality of the final manufactured products, such as semiconductor wafers and chips. These process chambers include gates and valves, such as slit valves, to isolate the chamber from the surrounding environment. These gates typically consist of a metal frame and sealing gaskets cross-linked to the metal frame. The materials used to manufacture these gaskets are typically made of fluoropolymers or fluoroelastics, and in some cases, perfluoroether rubber for highly contamination-resistant seals. These gates are commonly used in process reaction chambers during semiconductor fabrication to open and close the chamber.

[0027] Perfluoroelastomer (FFKM) materials possess chemical resistance, plasma resistance, and acceptable levels of compression set and mechanical properties. Therefore, FFKM materials have a wide range of applications. FFKM is typically prepared from perfluorinated monomers, including at least one monomer with a vulcanization point, which polymerizes to form a perfluoroelastomer containing vulcanization sites. A typical FFKM rubber composition includes the aforementioned perfluoroelastomer, a crosslinking agent, and the desired filler.

[0028] The inertness of perfluoroether rubber compositions offers advantages for use in harsh and clean environments, but due to their low surface energy, it is difficult to achieve sufficient strength and durability when bonded to metal plate and frame surfaces with higher surface energy.

[0029] Based on this, the embodiments of this specification propose a method for preparing a metal plate frame and fluororubber sealing assembly: such as Figure 1 As shown, including S1. Apply an adhesive to the bonding area between the metal plate frame and the perfluoroether rubber, dry and cool it. The adhesive is a trithiocyanate derivative solution. S2. A crosslinking agent and filler are added to the perfluoroether elastomer during the thin-pass compounding process to obtain a compound. The filler includes fluorinated silica, fluorinated titanium dioxide, or PFA micro powder. The mass of the filler is 2-10 wt% of the mass of the perfluoroether elastomer. The perfluoroether elastomer uses a nitrile-containing perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) as its vulcanizing point monomer, which is 1.5-3 wt% of the mass of the perfluoroether elastomer. S3. Place the mixed rubber sheet inside a metal frame, place the metal frame with the mixed rubber sheet inside a mold for hot pressing and vulcanization, remove the metal frame, clean the burrs, perform secondary vulcanization, and then perform radiation vulcanization to obtain the assembly.

[0030] In step S1, the metal frame undergoes mechanical processing, solvent cleaning and degreasing, and plasma treatment before coating. The mechanical processing includes sandblasting and grinding. The metal frame is made of aluminum-magnesium alloy 6061. The concentration of the trithiocyanate derivative solution is 2-6 wt%. The trithiocyanate derivative is monosodium trithiocyanate. The solvent in the trithiocyanate derivative solution is ethanol, methanol, or isopropanol solution. The drying temperature is 50-100 ℃, and the drying time is 8-15 min.

[0031] In S2, the crosslinking agent is tetraphenyltin or hexaoxane, wherein the tetraphenyltin is 0.3-0.5 wt% of the mass of the perfluoroether elastomer, and the hexaoxane is 0.5-1 wt% of the mass of the perfluoroether elastomer.

[0032] In S3, the hot-press vulcanization molding conditions are 140-160 ℃ × 10-20 min. The secondary vulcanization conditions are 180-220 ℃ × 4-12 hr. The radiation dose for radiation vulcanization is 30-100 kGy.

[0033] In this embodiment, the surface of the metal plate frame sealing area is sandblasted and then cleaned and degreased with ethanol and 5% HF solvent respectively. The adhesive is placed in an oven and dried at 60°C for 10 min. Other processes are common in the industry and will not be described in detail in the specific embodiment.

[0034] In this embodiment, hot-press vulcanization involves placing the metal frame in a mold and hot-pressing it at 160 ℃ for 16 min. Secondary vulcanization involves removing the metal frame with the bonded perfluoroether rubber seal, cleaning the burrs on the seal, and placing it in an oven for secondary vulcanization at 200 ℃ for 4 hr, followed by radiation vulcanization at a radiation dose of 40 kGy. This is a common process in the industry and will not be elaborated further in the specific embodiments.

[0035] The reagents used in this scheme are as follows: Perfluoroether elastomer, Solvay PFR95 raw rubber (USA); Fluorinated silicon dioxide and fluorinated titanium dioxide, for details of the preparation processes shown in Chinese invention patents CN115340648A and CN115651139A respectively; PFA micro powder, Daikin NEOFLON ACX-31 from Japan; Perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene was prepared in-house by Shanghai Senhuan New Materials Co., Ltd. For specific steps, please refer to Example 6 in US Patent US4138426A. Tetraphenyltin, Merck; Hexaoxane, Taihechang Chemical Co., Ltd. Example 1

[0036] S1. The metal plate frame is coated with adhesive, dried, and then cooled. The adhesive is an ethanol solution of sodium trithiocyanate with a concentration of 4 wt%. S2. During the thin-pass compounding process, 5 wt% fluorinated silica and 0.4 wt% tetraphenyltin are added to obtain the compound rubber. The vulcanization point monomer used in the perfluoroether elastomer is perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) containing a nitrile group, and the vulcanization point monomer is 1.5 wt% of the mass of the perfluoroether elastomer. S3. Place the compounded rubber sheet inside the metal frame, and then hot-press and vulcanize the metal frame containing the compounded rubber sheet in the mold. After removing the metal frame and cleaning the burrs on the perfluoroether rubber strip, perform a second vulcanization and then radiation vulcanization to obtain the assembly. Example 2

[0037] S1. The metal plate frame is coated with adhesive, dried, and then cooled. The adhesive is a methanol solution of sodium trithiocyanate with a concentration of 2 wt%. S2. During the thin-pass compounding process, 5 wt% fluorinated titanium dioxide and 0.4 wt% tetraphenyltin are added to obtain the compound rubber. The vulcanization point monomer used in the perfluoroether elastomer is perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) containing a nitrile group, and the vulcanization point monomer is 2.0 wt% of the mass of the perfluoroether elastomer. S3. Place the compounded rubber sheet inside the metal frame, and then hot-press and vulcanize the metal frame containing the compounded rubber sheet in the mold. After removing the metal frame and cleaning the burrs on the perfluoroether rubber strip, perform a second vulcanization and then radiation vulcanization to obtain the assembly. Example 3

[0038] S1. The metal plate frame is coated with adhesive, dried, and then cooled. The adhesive is an ethanol solution of sodium trithiocyanate with a concentration of 6 wt%. S2. During the thin-pass compounding process, 5 wt% PFA micro powder and 0.4 wt% tetraphenyltin are added to obtain the compound rubber. The vulcanization point monomer used in the perfluoroether elastomer is perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) containing a nitrile group, and the vulcanization point monomer is 3.0 wt% of the mass of the perfluoroether elastomer. S3. Place the compounded rubber sheet inside the metal frame, and then hot-press and vulcanize the metal frame containing the compounded rubber sheet in the mold. After removing the metal frame and cleaning the burrs on the fluororubber strip, perform a second vulcanization and then radiation vulcanization to obtain the assembly. Example 4

[0039] The difference between this embodiment and Embodiment 3 is that the mass of the fluorinated silica micropowder is 3 wt% of the perfluoroether elastomer. Example 5

[0040] The difference between this embodiment and Embodiment 3 is that the mass of the fluorinated silica micropowder is 10 wt% of the mass of the perfluoroether elastomer.

[0041] Comparative Example 1 The difference between this comparative example and Example 1 is that no additive was added in S2.

[0042] Comparative Example 2 The difference between this comparative example and Example 1 is that fluorinated silicon dioxide is replaced with ordinary silicon dioxide powder.

[0043] Comparative Example 3 The difference between this comparative example and Example 1 is that the mass of fluorinated silica is 1 wt% of the mass of the perfluoroether elastomer.

[0044] Comparative Example 4 The difference between this comparative example and Example 1 is that the mass of fluorinated silica is 13 wt% of the mass of the perfluoroether elastomer.

[0045] In the above embodiments and comparative examples, the prepared assemblies have groove dimensions of 5.5 mm × 336 mm and glue height of 14.65 mm.

[0046] Test methods The dimensions of the groove in the assembly to be tested are 5.5 mm × 336 mm, and the glue height is 14.65 mm.

[0047] The assembled parts were treated with a Triton 160 plasma degumming machine for 300 min at a power of 800 W. The plasma treatment cycle was as follows: O2 treatment for 50 min, in-situ treatment followed by a 50 min cooling period; then NF3 treatment for 50 min, in-situ treatment followed by a 50 min cooling period; finally, O2 / NF3 treatment for 50 min, in-situ treatment followed by a 50 min cooling period. The flow rate was 50 sccm (standard cubic centimeters per minute), the pressure was 500 mt, and the balance gas was N2.

[0048] Table 1. Bonding status of metal plate frame and perfluoroelastomer assembly

[0049] *The types of non-conforming products include perfluoroether rubber strips sticking to the mold during demolding after molding, containing impurities such as black spots and / or excessive crystal points (more than 5 particles larger than 0.1 mm), glue marks (caused by poor elastomer flowability), local delamination, and edge curling. **The types of non-compliance include localized degumming and excessive surface particle count (more than 5 particles larger than 0.1 mm, Keyence VHX-X1F, Japan).

[0050] A comparison of Examples 3, 4, and 5 shows that a lower content of fluorinated silica improves dispersion performance and results in a higher product qualification rate. However, a higher content of fluorinated silica, such as 10 wt% (Example 5), leads to agglomeration, an increase in the number of surface particles, and consequently, a higher number of defective products.

[0051] A comparison between Example 1 and Comparative Example 1 shows that Comparative Example 1 did not add any filler, and the number of unqualified products increased after secondary vulcanization. The main problems were degumming and edge curling.

[0052] The comparison between Example 1 and Comparative Example 2 shows that the number of defective products after secondary vulcanization and etching of the sample in Example 1 is low, indicating that fluorinated silica has a stronger bonding ability with perfluoroether elastomers than ordinary silica powder, resulting in a lower number of defective products.

[0053] The comparison of Example 1, Comparative Example 3 and Comparative Example 4 shows that when the amount of fluorinated silica added is small, the number of unqualified products after secondary vulcanization of the sample is large and the yield is low. When the amount of fluorinated silica added is large, due to the agglomeration of fluorinated silica, the number of unqualified products after secondary vulcanization of the sample increases and does not meet the production requirements.

[0054] Example 3, with the addition of 5 wt% PFA micro powder, and Example 4, with the addition of an appropriate amount of fluorinated silica, showed low defect rates and high yields after secondary sulfidation and etching.

[0055] In this specification, the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the descriptions of the embodiments described later are relatively simple, and relevant parts can be referred to the descriptions of the foregoing embodiments.

[0056] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a metal plate frame and fluororubber sealing assembly, characterized in that: include S1. The metal plate frame is coated with adhesive, dried and then cooled. The adhesive is a solution of trithiocyanate derivative. S2. A crosslinking agent and filler are added to the perfluoroether elastomer during the thin-pass compounding process to obtain a compound. The filler includes fluorinated silica, fluorinated titanium dioxide, or PFA micro powder. The mass of the filler is 2-10 wt% of the mass of the perfluoroether elastomer. The perfluoroether elastomer uses a nitrile-containing perfluoro-8-cyano-5-methyl-3,6-dioxa-1-octene (8-CNVE) as its vulcanizing point monomer, which is 1.5-3 wt% of the mass of the perfluoroether elastomer. S3. Place the mixed rubber sheet inside a metal frame, place the metal frame with the mixed rubber sheet inside a mold for hot pressing and vulcanization, remove the metal frame, clean the burrs, perform secondary vulcanization, and then perform radiation vulcanization to obtain the assembly.

2. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S1, the metal plate is sequentially subjected to mechanical treatment, solvent cleaning and degreasing, and plasma treatment before coating. The mechanical treatment includes sanding and sandblasting.

3. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: The metal frame is made of aluminum-magnesium alloy 6061.

4. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S1, the solution concentration of the trithiocyanate derivative is 2-6 wt%.

5. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S1, the trithiocyanate derivative is a monosodium trithiocyanate salt.

6. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S1, the solvent in the trithiocyanate derivative solution is ethanol, methanol, or isopropanol.

7. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S1, the drying temperature is 50-100 ℃ and the drying time is 8-15 min.

8. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S2, the crosslinking agent is tetraphenyltin or hexaoxane, wherein the tetraphenyltin is 0.3-0.5 wt% of the mass of the perfluoroether elastomer, and the hexaoxane is 0.5-1 wt% of the mass of the perfluoroether elastomer.

9. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S3, the hot-press vulcanization molding conditions are 140-160 ℃ × 10-20 min.

10. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S3, the vulcanization conditions for the secondary vulcanization are 180-220 ℃ × 4-12 hr.

11. The method for preparing the metal plate frame and fluororubber sealing assembly according to claim 1, characterized in that: In S3, the radiation dose for radiation sulfurization is 30-100 kGy.

12. A metal plate frame and fluororubber sealing assembly, characterized in that: It is prepared by the method described in any one of claims 1-11.

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