Fluororubber compound, preparation method thereof and semiconductor sealing assembly

Abstract

The invention relates to the technical field of rubber sealing materials, in particular to a fluororubber compound, a preparation method thereof and a semiconductor sealing assembly. The invention relates to a preparation method. Providing a SiC-coated SiO2 composite filler and modified boron carbide, and mixing the SiC-coated SiO2 and the modified boron carbide according to a first predetermined proportion to form a plasma-resistant composite filler; the method comprises the following steps: providing raw fluororubber, a vulcanizing agent, a fluorine-based low-temperature-resistant plasticizer and an additive, plastifying the raw fluororubber, mixing the plastified raw fluororubber with the additive, and carrying out first-stage mixing; after the first-stage mixing is completed, continuing to add the plasma-resistant composite filler for second-stage mixing; after the second-stage mixing is completed, continuing to add a fluorine-series low-temperature-resistant plasticizer for third-stage mixing; and after the third-stage mixing is finished, rolling to obtain master batch, mixing a vulcanizing agent and the master batch, and mixing to obtain the fluororubber mixed rubber. The problems that in the prior art, the interface bonding strength is insufficient, and interface stripping is prone to occurring under plasma bombardment and temperature cycle impact are solved.

Description

Technical Field

[0001] This invention relates to the field of rubber sealing materials technology, and in particular to a fluororubber compound and its preparation method, and a semiconductor sealing component. Background Technology

[0002] Semiconductor manufacturing processes are typically carried out in high-temperature, high-vacuum, and highly corrosive plasma environments. The plasma formed by the gas places extremely high demands on sealing materials. Fluororubber (FKM) and perfluororubber (FFKM) have become core materials for semiconductor sealing components due to their excellent chemical resistance and thermal stability. To ensure that the wafer is not contaminated, the sealing material must have an extremely low particle release rate, excellent resistance to plasma etching, and a wide temperature range sealing capability.

[0003] In existing technologies, the main approach to solving the above problems is to use a single perfluororubber (FFKM) as the matrix, add traditional reinforcing fillers such as carbon black, and improve its density and corrosion resistance through high-temperature secondary vulcanization. This improves the material's heat resistance and chemical inertness to some extent. However, the traditional filler and the fluororubber raw rubber only undergo physical adsorption, resulting in insufficient interfacial bonding strength. Under plasma bombardment and temperature cycling, interfacial delamination easily occurs, leading to particle shedding and wafer contamination. At the same time, the delamination interface becomes a channel for plasma erosion, accelerating material degradation. Summary of the Invention

[0004] To address the problems of insufficient interfacial bonding strength and easy interfacial delamination under plasma bombardment and temperature cycling, this invention provides a fluororubber compound, its preparation method, and a semiconductor sealing component.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing fluororubber compound, the method comprising: providing SiC@SiO2 composite filler and modified boron carbide, mixing SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler; providing fluororubber raw rubber, vulcanizing agent, fluorinated low-temperature resistant plasticizer and additives, plasticizing the fluororubber raw rubber and mixing it with the additives and performing a first-stage mixing; after completing the first-stage mixing, continuing to add the plasma-resistant composite filler for a second-stage mixing; after completing the second-stage mixing, continuing to add the fluorinated low-temperature resistant plasticizer for a third-stage mixing; rolling the mixture after completing the third-stage mixing to obtain a masterbatch, mixing the vulcanizing agent and the masterbatch and then mixing to obtain a fluororubber compound, wherein the SiC@SiO2 composite filler and modified boron carbide in the fluororubber compound form hydrogen bonds with the fluororubber, and the modified boron carbide forms covalent bonds with the fluororubber.

[0006] Preferably, the method provides SiC@SiO2 composite filler and modified boron carbide. The method of mixing SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler includes: providing silicon carbide, a solvent, and tetraethyl orthosilicate; dispersing silicon carbide in the solvent and ultrasonically treating it for 20-30 min; adding ammonia water at a stirring rate of 100-200 r / min to obtain a mixture; the pH of the mixture being 9.2-9.5; adding tetraethyl orthosilicate to the mixture; and reacting at a constant temperature of 50-55°C for 5-7 h. After the reaction is completed, the SiC@SiO2 composite filler is obtained by centrifugation and drying. Boron nitride, solvent and titanate coupling agent are provided. Boron nitride is dispersed in solvent and then titanate coupling agent is added. The mixture is refluxed and stirred at 70~80℃ for 3~4h to carry out the reaction. After the reaction is completed, the mixture is filtered, washed and dried to obtain modified boron nitride, wherein the mass fraction of titanate coupling agent is 3~4wt%. SiC@SiO2 and modified boron carbide are mixed at a mass ratio of 1:0.8~1.2 to form a plasma-resistant composite filler.

[0007] Preferably, the fluororubber raw rubber, vulcanizing agent, fluorinated low-temperature plasticizer, and additives include: providing fluororubber and perfluorinated rubber, mixing fluororubber and perfluorinated rubber at a mass ratio of 70~80:20~30 to obtain fluororubber raw rubber, wherein the difference in Mooney viscosity between fluororubber and perfluorinated rubber is ≤20; providing perfluoropolyether ester and fluoroalkylphosphonate, mixing perfluoropolyether ester and fluoroalkylphosphonate at a mass ratio of 6~8:1 to obtain fluorinated low-temperature plasticizer; providing 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, mixing 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate at a mass ratio of 1:1.2~1.5 to obtain vulcanizing agent; the additives include acid scavengers, processing aids, and antioxidants, wherein the acid scavengers include magnesium oxide and calcium hydroxide, and the mass ratio of magnesium oxide to calcium hydroxide is 2:1.

[0008] Preferably, the process of plasticizing the fluororubber raw rubber and mixing it with additives to carry out the first stage of mixing includes: plasticizing the fluororubber raw rubber at 35~40 rpm for 2~4 min; after plasticizing, mixing the plasticized fluororubber raw rubber with additives and mixing at a temperature of 45~50℃ and a stirring speed of 30~35 rpm for 2~4 min to complete the first stage of mixing.

[0009] Preferably, the second stage of mixing after completing the first stage of mixing involves adding plasma-resistant composite filler: dividing the plasma-resistant composite filler into two halves according to its components; after completing the first stage of mixing, adding one half of the plasma-resistant composite filler and mixing at a temperature of 55-60°C and a stirring speed of 45-50 rpm for 3-6 minutes; adding the other half of the plasma-resistant composite filler and mixing at a temperature of 55-60°C and a stirring speed of 45-50 rpm for 3-6 minutes; and then heating the temperature from 55-60°C to 85-90°C to complete the second stage of mixing.

[0010] Preferably, after completing the second stage of mixing, the third stage of mixing involves adding a fluorinated low-temperature resistant plasticizer and mixing at a stirring speed of 35-40 rpm for 2-4 minutes to complete the third stage of mixing.

[0011] Preferably, the mixture after the third stage of mixing is subjected to roll pressing to obtain masterbatch, and the vulcanizing agent and masterbatch are mixed and then compounded to obtain fluororubber compound, which includes: providing a roll pressing assembly, discharging the compound after the third stage of mixing at 85~90°C to obtain initial colloid, rolling the colloid in the roll pressing assembly at a roller gap of less than 1mm and a roller temperature of ≤50°C 4~5 times to form initial roll-pressed sheets, and letting the roll-pressed sheets stand at room temperature for 10~12h to obtain masterbatch; and then... Add vulcanizing agent to the rubber at 40~45℃ and mix at a stirring speed of 35~40rpm for 2~4min. Continue to heat the rubber from the discharge temperature of 40~45℃ to 75~80℃ to discharge the rubber and form the colloid to be treated. The colloid to be treated is then rolled 2~3 times in a roller pressing assembly at a roller gap of less than 2~3mm and a roller temperature of ≤50℃ to form the roll sheet to be treated. The roll sheet to be treated is then left to stand at room temperature for 10~12h to obtain the fluororubber compound. To solve the above-mentioned technical problems, the present invention provides another technical solution as follows: a fluororubber compound, wherein the raw materials for preparing the fluororubber compound include: 100 parts of fluororubber raw rubber, 20-30 parts of plasma-resistant composite filler, 4-6 parts of fluorine-based low-temperature resistant plasticizer; 4-5 parts of vulcanizing agent; and 4-6 parts of additives; wherein the raw materials for the plasma-resistant composite filler include SiC@SiO2 composite filler and modified boron carbide; and the mass ratio of the SiC@SiO2 composite filler to modified boron carbide is 1:0.8-1.2.

[0012] Preferably, the fluororubber raw rubber comprises fluororubber and perfluororubber, wherein the mass ratio of fluororubber to perfluororubber is 70~80:20~30, and the difference in Mooney viscosity between fluororubber and perfluororubber is ≤20; the fluorinated low-temperature resistant plasticizer comprises perfluoropolyether ester and fluoroalkylphosphonate, wherein the mass ratio of perfluoropolyether ester to fluoroalkylphosphonate is 6~8:1; the vulcanizing agent comprises 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, wherein the mass ratio of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to triallyl isocyanurate is 1:1.2~1.5; the additives comprise acid scavengers, processing aids, and antioxidants, wherein the acid scavengers comprise magnesium oxide and calcium hydroxide, wherein the mass ratio of magnesium oxide to calcium hydroxide is 2:1.

[0013] To solve the above-mentioned technical problems, the present invention provides another technical solution as follows: a semiconductor sealing component, wherein at least a portion of the semiconductor sealing component is made of the above-mentioned fluororubber compound.

[0014] Compared with the prior art, the fluororubber compound and its preparation method, as well as the semiconductor sealing assembly provided by the present invention, have the following beneficial effects: 1. A method for preparing fluororubber compound provided by embodiments of the present invention, the method comprising: providing SiC@SiO2 composite filler and modified boron carbide, mixing SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler; providing fluororubber raw rubber, vulcanizing agent, fluorinated low-temperature resistant plasticizer and additives, plasticizing the fluororubber raw rubber and mixing it with the additives and performing a first stage of mixing; after completing the first stage of mixing, continuing to add the plasma-resistant composite filler for a second stage of mixing; after completing the second stage of mixing, continuing to add the fluorinated low-temperature resistant plasticizer for a third stage of mixing; performing a roll pressing treatment on the mixture after completing the third stage of mixing to obtain a masterbatch, mixing the vulcanizing agent and the masterbatch and then mixing to obtain a fluororubber compound, wherein the SiC@SiO2 composite filler and modified boron carbide in the fluororubber compound form hydrogen bonds with the fluororubber, and the modified boron carbide forms covalent bonds with the fluororubber. This embodiment, by precisely controlling the sol-gel preparation conditions of SiC@SiO2, the grafting conditions of the modified boron nitride coupling agent, and the compounding ratio of the two fillers, constructs a dual-active interface on the filler surface that can form hydrogen bonds and covalent bonds with fluororubber, respectively. The plasma-resistant composite filler prepared in this way, after being compounded with fluororubber, exhibits synergistic effects between the two interfaces, effectively suppressing filler peeling from the rubber matrix under plasma environment and wide temperature range conditions, thus reducing the problem of particle release at the material interface level.

[0015] 2. This invention also provides a fluororubber compound preparation material comprising: 100 parts of fluororubber raw rubber, 20-30 parts of plasma-resistant composite filler, 4-6 parts of fluorine-based low-temperature resistant plasticizer, 4-5 parts of vulcanizing agent, and 4-6 parts of additives; the plasma-resistant composite filler comprises SiC@SiO2 composite filler and modified boron carbide; the mass ratio of SiC@SiO2 composite filler to modified boron carbide is 1:0.8-1.2. The fluororubber compound of this invention provides a hydrogen bond network and covalent bond bridging to form a complementary and reinforced composite structure at the filler-rubber interface. When subjected to plasma bombardment and wide-temperature-range thermal cycling, the composite structure can effectively resist stress damage at the interface and inhibit the filler from peeling off from the rubber matrix, thereby achieving a low-particle-release fluororubber compound for semiconductor sealing at the material interface level.

[0016] 3. This embodiment of the invention also provides a semiconductor sealing assembly, wherein at least a portion of the semiconductor sealing assembly is made of the aforementioned fluororubber compound. The semiconductor sealing assembly described in this embodiment uses a fluororubber compound with dual interfacial bonding characteristics of hydrogen bonds and covalent bonds as the material. In a plasma environment, it can effectively suppress the release of particles caused by filler peeling from the matrix, and simultaneously maintain low-temperature elasticity and high-temperature resistance to compression set under wide temperature range conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 present 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 schematic diagram of the preparation method of fluororubber compound provided in the first embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the formation of the SiC@SiO2 core-shell structure.

[0020] Figure 3 This is a schematic diagram of the formation of modified boron nitride.

[0021] Figure 4 This is a schematic diagram of the plasma protection mechanism of fluororubber compound.

[0022] Figure 5 This is a schematic diagram of the structure of the semiconductor sealing assembly provided in the third embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] In the embodiments provided by this invention, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0025] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also recognize that the embodiments described in the specification are optional embodiments, and the actions and modules involved are not necessarily essential to the invention.

[0026] In various embodiments of the present invention, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0027] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It is particularly important to note that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0028] Please see Figure 1 The first embodiment of the present invention provides a method for preparing fluororubber compound, the method comprising: S1 provides SiC@SiO2 composite filler and modified boron carbide, and mixes SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler; S2 provides fluororubber raw material, vulcanizing agent, fluorine-based low-temperature resistant plasticizer and additives. After plasticizing the fluororubber raw material, it is mixed with the additives and then carried out the first stage of compounding. S3, after completing the first stage of mixing, continue to add plasma-resistant composite filler for the second stage of mixing; S4, after completing the second stage of mixing, continue to add fluorine-based low-temperature resistant plasticizers for the third stage of mixing; S5. Roll pressing is performed on the mixture after the third stage of mixing to obtain masterbatch. The vulcanizing agent and masterbatch are mixed and then mixed to obtain fluororubber compound. In the fluororubber compound, SiC@SiO2 composite filler and modified boron carbide form hydrogen bonds with fluororubber, and modified boron carbide forms covalent bonds with fluororubber.

[0029] Understandable, please combine them. Figure 2 and Figure 3 The method for preparing fluororubber compound in this embodiment involves compounding SiC@SiO2 composite filler prepared by the sol-gel method with modified boron nitride, and combining this with a staged mixing process. This allows the two fillers to form dual interfacial bonds of hydrogen bonds and covalent bonds in the fluororubber raw rubber, solving the problems of poor interfacial compatibility between inorganic fillers and fluororubber, easy agglomeration, and easy peeling and particle formation under plasma environment and temperature cycling shock in the prior art. The SiC@SiO2 composite filler provided in step S1 of this embodiment is prepared by the sol-gel method, which can form a uniform amorphous SiO2 shell on the surface of SiC particles. The surface of this shell is rich in Si-OH silanol active sites. Specifically, the modified boron nitride introduces active groups that can participate in vulcanization on the surface of boron nitride. The plasma-resistant composite filler formed by mixing the two has the interfacial activity of forming both hydrogen bonds and covalent bonds with fluororubber.

[0030] Further, in steps S2 to S4. In step S2, the vulcanizing agent, fluorinated low-temperature plasticizer, and additives completed the first stage of mixing, maintaining the appropriate viscosity of the fluororubber raw rubber at a lower temperature. Step S3 involves the second stage of mixing, which facilitates full contact between the Si-OH groups on the surface of the SiC@SiO2 composite filler and the active hydrogen atoms in the fluororubber molecular chain, forming hydrogen bonds. Specifically, the active hydrogen atoms provided by the methylene groups (-CH2-) in the fluororubber molecular chain can form -CH2-OH…O-Si and -OH-H…OB- type hydrogen bond networks with the oxygen atoms in the silanol groups (-Si-OH) on the SiC@SiO2 surface and the edge hydroxyl groups (-B-OH) on the modified boron nitride surface that are not completely covered by the coupling agent. Although hydrogen bonds are non-covalent bonds, they can significantly improve the dispersibility of the SiC@SiO2 composite filler in the fluororubber raw rubber and buffer interfacial stress. In step S4, the third stage of mixing involves returning to low-temperature conditions and adding a low-temperature resistant plasticizer to prevent the fluororubber molecular chains from disintegrating due to high temperatures, while also protecting the already formed hydrogen bond network from damage. In step S5, when the vulcanizing agent is mixed with the masterbatch, the titanate coupling agent graft layer on the surface of the modified boron nitride further reacts with the fluororubber crosslinking network during the vulcanization stage to form a BO-Ti-Rub covalent bond structure, enabling the modified boron nitride to achieve a strong molecular-level bond with the rubber matrix.

[0031] It should be understood that in this embodiment, SiC@SiO2 prepared by the sol-gel method provides hydrogen bonding interfacial interactions, while boron nitride modified by titanate coupling agent provides covalent bonding interfacial interactions. A staged mixing process is employed to ensure the full formation of both interfacial interactions in the fluororubber raw rubber. In the fluororubber compound thus prepared, a dual interfacial bonding network of hydrogen bonds and covalent bonds is established between the two fillers and the fluororubber. Under plasma bombardment and wide-temperature thermal cycling, stress damage and particle delamination are not easily generated at the filler-rubber interface, thereby maintaining long-term sealing reliability under the harsh conditions of semiconductors.

[0032] Specifically, in step S1, SiC@SiO2 composite filler and modified boron carbide are provided. The process of mixing SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler includes: Silicon carbide, solvent, and tetraethyl orthosilicate are provided. Silicon carbide is dispersed in the solvent and ultrasonically treated for 20-30 min. Ammonia is added at a stirring rate of 100 r / min-200 r / min to obtain a mixture with a pH of 9.2-9.5. Tetraethyl orthosilicate is added to the mixture and reacted at a constant temperature of 50-55℃ for 5-7 h. After the reaction is completed, the mixture is centrifuged and dried to obtain SiC@SiO2 composite filler. Boron nitride, solvent, and titanate coupling agent are provided. Boron nitride is dispersed in the solvent and then the titanate coupling agent is added. The mixture is refluxed and stirred at 70-80℃ for 3-4 h to carry out the reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain modified boron nitride, wherein the mass fraction of the titanate coupling agent is 3-4 wt%. SiC@SiO2 and modified boron carbide are mixed at a mass ratio of 1:0.8-1.2 to form a plasma-resistant composite filler.

[0033] Understandably, please refer to Figure 2 In this embodiment, the SiC@SiO2 composite filler was prepared using the sol-gel method. First, silicon carbide was dispersed in a solvent and ultrasonically treated for 20-30 minutes to fully disperse the SiC particles and expose the Si-OH active sites formed on their surface by spontaneous oxidation in the air. Then, ammonia was added at a stirring rate of 100-200 r / min to adjust the pH to 9.2-9.5. The weakly alkaline environment promoted the deprotonation reaction of Si-OH to generate Si-O. - This provides active anchor sites for the subsequent adsorption and condensation of tetraethyl orthosilicate (TEOS). After the addition of TEOS, the reaction is carried out at a constant temperature of 50-55℃ for 5-7 hours. This temperature range ensures a suitable rate for the TEOS hydrolysis and condensation reaction while avoiding SiC grain coarsening or increased surface defects caused by high temperatures. After the reaction is completed, a continuous and uniform amorphous SiO2 shell is formed on the surface of the SiC particles. This shell is rich in Si-OH active groups, which can form stable hydrogen bonds with the fluororubber molecular chains.

[0034] For further details, please refer to Figure 3 In this embodiment, the modified boron nitride was prepared by surface grafting modification with a titanate coupling agent. Hexagonal boron nitride was dispersed in a solvent, and the -B-OH hydroxyl groups present at its edges and surface provided reaction sites for the coupling agent. After adding 3-4% (w / w) of titanate coupling agent, the mixture was refluxed and stirred at 70-80℃ for 3-4 hours. Under these temperature and time conditions, the coupling agent and the edge hydroxyl groups of boron nitride underwent a condensation reaction to form BO-Ti covalent bonds, transforming the boron nitride surface from a highly polar, easily agglomerated state to a low-polarity, easily dispersed state. Controlling the titanate coupling agent dosage within the range of 3-4% ensured sufficient surface grafting rate to improve dispersibility while avoiding the formation of multiple physical adsorption layers on the filler surface by excessive coupling agent, which could affect the subsequent vulcanization reaction.

[0035] Furthermore, in this embodiment, SiC@SiO2 and modified boron nitride are compounded at a mass ratio of 1:0.8-1.2. The Si-OH groups provided by the SiC@SiO2 shell mainly contribute hydrogen bonding, while the BO-Ti groups on the surface of the modified boron nitride contribute covalent bonding. When the mass ratio of the two is controlled within the above range, hydrogen bonds and covalent bonds form a synergistically reinforced composite interface layer at the filler-rubber interface. The hydrogen bond network provides basic interfacial bonding and stress buffering capacity, while the covalent bonds form a BO-Ti-Rub chemical bridging structure during the vulcanization stage, giving the interface stronger anti-peeling ability. The two types of interfacial interactions work together to enable the composite filler to achieve good initial dispersion in fluororubber raw rubber while resisting the damage caused by plasma bombardment and thermal cycling stress.

[0036] It should be understood that this embodiment, by precisely controlling the sol-gel preparation conditions of SiC@SiO2, the coupling agent grafting conditions of modified boron nitride, and the compounding ratio of the two fillers, constructs a dual-active interface on the filler surface that can form hydrogen bonds and covalent bonds with fluororubber, respectively. The plasma-resistant composite filler prepared in this way, after being compounded with fluororubber, exhibits synergistic effects from the two interfaces, effectively suppressing the peeling of the filler from the rubber matrix under plasma environment and wide temperature range conditions, thus reducing the problem of particle release at the material interface level.

[0037] It should be noted that the ultrasonic treatment time for dispersing silicon carbide in a solvent can also be 20-25, 22-28, or 26-30 min, the stirring rate can also be 100-180 r / min or 150-200 r / min, and the pH of the mixture can also be 9.2-9.4 or 9.3-9.5. Tetraethyl orthosilicate can be added to the mixture and reacted at a constant temperature of 50-54℃ or 52-55℃ for 5-6.5 h or 6-7 h. Boron nitride can be dispersed in a solvent and then a titanate coupling agent can be added, and the reaction can be carried out under reflux and stirring at 70-75℃ or 73-80℃ for 3-4 h. SiC@SiO2 and modified boron carbide can also be mixed at a mass ratio of 1:0.9, 1:1, or 1:1.1 to form a plasma-resistant composite filler.

[0038] Specifically, the preparation principle of SiC@SiO2 is as follows: The Si dangling bonds on the surface of SiC particles spontaneously oxidize in air, forming stable Si-OH active sites. In a weakly alkaline environment regulated by ammonia, the Si-OH undergoes a deprotonation reaction. Si-OH + OH- → Si-O- + H2O The added tetraethyl orthosilicate (TEOS) undergoes hydrolysis under isothermal and weakly alkaline conditions at 55°C, producing silicic acid monomers and ethanol.

[0039] The silicic acid monomers generated by hydrolysis adsorb onto the Si-O- active sites on the SiC surface, forming Si–O–Si covalent bonds through dehydration condensation: Si-O-+Si(OH)4→Si–O–Si(OH)3+OH- Subsequently, silica monomers continue to condense on the formed SiO2 precursor, gradually growing into a continuous and dense amorphous SiO2 shell: Si(OH)4+(OH)3Si–O–Si→(-Si-O-Si-O-Si-)+H2O Furthermore, this invention employs a sol-gel method to prepare SiC@SiO2 composite fillers. Compared to the traditional high-temperature thermal oxidation method, this method forms a SiO2 shell on the surface of SiC particles through the hydrolysis and condensation of tetraethyl orthosilicate under a mild condition of 55°C. This avoids problems such as SiC grain coarsening, increased surface defects, uneven shell layer, and microcracks caused by high-temperature thermal oxidation. Simultaneously, the SiO2 shell prepared by the sol-gel method is rich in Si-OH active sites, which can form stable hydrogen bonds with the fluororubber matrix, improving the interfacial bonding strength between the filler and the rubber and reducing the risk of particle release.

[0040] Furthermore, after hexagonal boron carbide is surface-grafted with a titanate coupling agent, only a surface chemical change occurs, introducing BO-Ti covalent bonds. The internal crystal structure and chemical composition remain unchanged. Physically, it transforms from a highly polar, easily agglomerated powder into a low-polarity, easily dispersible powder, thereby achieving efficient interfacial bonding with the fluororubber matrix. The reaction mechanism is as follows: h-BN-OH+Ti(OR)4→h-BN-O-Ti(OR)3+ROH; Furthermore, in step S2 above, the fluororubber raw material, vulcanizing agent, fluorinated low-temperature plasticizer, and additives provided include: The product provides fluororubber and perfluorinated rubber, wherein fluororubber and perfluorinated rubber are mixed at a mass ratio of 70~80:20~30 to obtain fluororubber raw rubber, wherein the difference in Mooney viscosity between fluororubber and perfluorinated rubber is ≤20; it also provides perfluorinated polyether ester and fluoroalkyl phosphonate, wherein perfluorinated polyether ester and fluoroalkyl phosphonate are mixed at a mass ratio of 6~8:1 to obtain a fluorinated low-temperature resistant plasticizer; it further provides 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, wherein 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate are mixed at a mass ratio of 1:1.2~1.5 to obtain a vulcanizing agent; additives include acid scavengers, processing aids and antioxidants, wherein the acid scavengers include magnesium oxide and calcium hydroxide, wherein the mass ratio of magnesium oxide and calcium hydroxide is 2:1.

[0041] Understandably, in this embodiment, the fluororubber raw rubber is prepared by blending fluororubber (FKM) and perfluororubber (FFKM) at a mass ratio of 70-80:20-30. Fluororubber has good processing fluidity, providing good processing performance during mixing and molding; perfluororubber, due to the complete replacement of carbon-hydrogen bonds in its molecular chain by fluorine atoms, has higher chemical inertness and resistance to plasma etching. After blending, fluororubber imparts good processability to the rubber compound, while perfluororubber enhances the structural stability of the vulcanizate in a high-temperature plasma environment. Limiting the Mooney viscosity difference between the two to ≤20 avoids uneven blending caused by excessive viscosity differences, ensuring uniform micro-mixing of the two raw rubbers during the mixing process.

[0042] Furthermore, in this embodiment, the fluorinated low-temperature plasticizer is a compound of perfluoropolyether ester and fluoroalkylphosphonate in a mass ratio of 6-8:1. Perfluoropolyether ester has flexible perfluoroether segments, and its main chain structure is similar to that of fluororubber molecules. The two exhibit excellent compatibility, allowing them to insert between fluororubber molecular chains, increasing the free volume of the molecular chains, weakening interchain forces, thereby lowering the glass transition temperature and improving chain mobility at low temperatures. Fluorinated alkylphosphonate has good compatibility with the surfaces of fluororubber and fillers, synergistically improving interfacial bonding. Simultaneously, the phosphonate groups in its molecular structure help form a stable distribution in the rubber matrix, preventing the plasticizer from migrating and precipitating to the surface during long-term use. After compounding, while ensuring high-temperature resistance and non-volatility, the two can effectively improve the toughness of fluororubber at -40℃, preventing low-temperature hardening.

[0043] Furthermore, in this embodiment, the vulcanizing agent is a compound of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate (TAIC) in a mass ratio of 1:1.2~1.5. Tert-butylperoxyhexane, as a peroxide vulcanizing agent, decomposes under heating conditions to generate free radicals, initiating a cross-linking reaction of the fluororubber molecular chains; triallyl isocyanurate, as a co-crosslinking agent, can participate in the formation of the cross-linking network, increasing the number of crosslinking points and adjusting the crosslinking density. The compounding of the two in the above ratio can form a moderately cross-linked network structure during vulcanization, ensuring that the vulcanized rubber has good resistance to compression set at 250°C while maintaining sufficient chain segment movement space to maintain low-temperature elasticity, thus balancing high-temperature stability and low-temperature flexibility.

[0044] Furthermore, in this embodiment, the acid absorbent is composed of highly active magnesium oxide and calcium hydroxide in a mass ratio of 2:1. Fluororubber releases trace amounts of hydrogen fluoride (HF) during vulcanization and high-temperature use. If hydrogen fluoride accumulates in the rubber compound, it will catalyze the degradation reaction of the fluororubber molecular chains. Both magnesium oxide and calcium hydroxide can neutralize hydrogen fluoride; their combined use can improve acid absorption efficiency. Simultaneously, the introduction of calcium hydroxide helps improve the compression set properties of the vulcanized rubber.

[0045] It should be understood that this embodiment, by limiting the formulation of the raw rubber system, plasticizer system, vulcanization system and acid scavenger system, achieves synergistic matching of the raw rubber system, plasticizer system, vulcanization system and acid scavenger system, so that the fluororubber compound has good low-temperature elasticity and high-temperature compression set resistance in a wide temperature range. The fluororubber compound prepared thus meets the harsh operating conditions of semiconductor processes from -40°C to 250°C.

[0046] It should be noted that, in this embodiment, the mass ratio of fluororubber to perfluororubber can also be 70~75:20~25, 74~80:24~30, or 77~80:20~26; the mass ratio of perfluoropolyether ester to fluoroalkylphosphonate can also be 7:1, 6.5:1, or 7.5:1; and the mass ratio of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to triallyl isocyanurate can also be 1:1.3 or 1:1.4.

[0047] Furthermore, in step S2 above, the process of plasticizing the fluororubber raw rubber and mixing it with additives to carry out the first stage of mixing includes: plasticizing the fluororubber raw rubber at 35~40 rpm for 2~4 min; after plasticizing, mixing the plasticized fluororubber raw rubber with additives, and mixing at a temperature of 45~50℃ and a stirring speed of 30~35 rpm for 2~4 min to complete the first stage of mixing.

[0048] Understandably, in this embodiment, the compounded fluororubber raw rubber is first masticated at a speed of 35-40 rpm for 2-4 minutes. The purpose of mastication is to further mix the fluororubber and perfluororubber raw rubber evenly through the shearing action of the rollers, and at the same time, to break down the physical entanglement between the raw rubber molecular chains through mechanical shearing, thereby reducing the viscosity of the rubber compound and facilitating the subsequent mixing of additives. Controlling the mastication speed within the range of 35-40 rpm avoids the problem of excessive Mooney viscosity reduction due to excessively high speed, which would affect the mechanical properties of the vulcanized rubber; if the speed is too low, the shearing action will be insufficient, making it difficult to achieve sufficient mixing and viscosity homogenization of the two raw rubbers in a short time. After mastication, the masticated fluororubber raw rubber and additives are mixed at a temperature of 45-50°C and a stirring speed of 30-35 rpm for 2-4 minutes to complete the first stage of mixing. The first stage of mixing is controlled at a low temperature range of 45-50℃. Additives such as acid scavengers (e.g., magnesium oxide and calcium hydroxide), processing aids (e.g., perfluoropolyether wax), and antioxidants (e.g., hindered fluorinated phenols) are all small molecules or low-melting-point substances. If the mixing temperature is too high, these additives may volatilize or thermally decompose before being fully dispersed, leading to loss of effective components and deviation of the compound formulation from the design values. If the mixing temperature is too low, the rubber viscosity will be too high, making it difficult for the additives to achieve uniform dispersion within a limited time. The 45-50℃ temperature range ensures the stability of the additives while maintaining a suitable flow state for the fluororubber raw rubber. Simultaneously, controlling the stirring speed at a low speed range of 30-35 rpm further reduces shear heat generation during mixing, preventing additive decomposition due to localized overheating. The mixing time is controlled at 2-4 minutes, ensuring initial uniform mixing of the additives and raw rubber while avoiding prolonged low-temperature mixing that would reduce mixing efficiency. Under these conditions, the additives can form a relatively uniform initial dispersed phase in the fluororubber raw rubber.

[0049] It should be understood that the first-stage mixing in this embodiment provides a uniformly distributed initial compound for the subsequent addition of plasma-resistant composite fillers, facilitating the uniform dispersion of each component in the final fluororubber compound. It should be noted that the fluororubber raw rubber can also be plasticized at 35-38 rpm or 36-40 rpm for 2-4 minutes; after plasticizing, the plasticized fluororubber raw rubber and additives are mixed, and the first-stage mixing can be completed by mixing at a temperature of 45-48°C or 46-50°C and a stirring speed of 30-34 rpm or 32-35 rpm for 2-4 minutes.

[0050] Furthermore, in step S3 above, the second stage of mixing after completing the first stage of mixing involves adding plasma-resistant composite filler: dividing the plasma-resistant composite filler into two halves according to its components; after completing the first stage of mixing, adding one half of the plasma-resistant composite filler and mixing at a temperature of 55-60°C and a stirring speed of 45-50 rpm for 3-6 minutes; adding the other half of the plasma-resistant composite filler and mixing at a temperature of 55-60°C and a stirring speed of 45-50 rpm for 3-6 minutes; and then heating the temperature from 55-60°C to 85-90°C to complete the second stage of mixing.

[0051] Understandably, plasma-resistant composite fillers are composed of SiC@SiO2 and modified boron nitride in a specific ratio, both of which possess high specific surface area and surface activity. If all the fillers are added to the rubber compound at once, a large number of high-specific-surface-area particles simultaneously enter the rubber matrix, rapidly adsorbing the rubber molecular chains. This causes a sharp increase in the rubber compound's viscosity within a short period, forming a high-viscosity paste-like system. Under this high-viscosity state, shear force is difficult to effectively transfer to the interior of the filler agglomerates. During subsequent mixing, the relative movement between filler particles is restricted, making it difficult to break up the already formed agglomerates, thus leaving localized agglomerated areas in the rubber compound.

[0052] In this embodiment, the plasma-resistant composite filler is divided into two halves and added in two stages. After adding the first half of the filler, it is mixed at 55-60℃ and 45-50 rpm for 3-6 minutes. The medium temperature of 55-60℃ maintains the appropriate fluidity of the fluororubber raw rubber, which is beneficial for the wetting and dispersion of the filler particles and prevents the volatilization of small molecule additives due to excessive temperature. The medium-high speed of 45-50 rpm provides sufficient shear force to effectively break up the added filler agglomerates and uniformly disperse them in the rubber matrix. The 3-6 minute mixing time ensures that the filler completes the initial wetting and distribution in the matrix. After the first batch of filler forms a relatively uniform dispersion in the rubber compound, although the viscosity of the rubber compound increases, it still remains within the processable range. At this time, the second batch of filler is added. After adding the other half of the filler, it is mixed again for 3-6 minutes under the same medium temperature and medium-high speed conditions. At this point, the second batch of fillers enters the rubber compound system that already contains the first batch of dispersing fillers. Although the viscosity of the rubber compound increases somewhat, the second batch of fillers can achieve faster dispersion during mixing by utilizing the established shear field, as the first batch of fillers has already formed a certain dispersion network. The interval mixing between the two additions results in a stepwise increase in the viscosity of the rubber compound, avoiding dispersion difficulties caused by sudden viscosity changes. Finally, the temperature is heated from 55~60℃ to 85~90℃. This heating process further reduces the viscosity of the rubber compound, allowing the fillers to complete their final orientation and interfacial wetting at high temperatures, while simultaneously expelling air and low-molecular-weight volatiles entrained during mixing.

[0053] It should be understood that this embodiment achieves gradient dispersion and gradual coating of the filler by adding the high specific surface area plasma-resistant composite filler in two stages, combined with medium-temperature and medium-speed mixing conditions and staged temperature rise and glue removal. This avoids the problems of sudden viscosity change and local agglomeration of the rubber compound caused by adding the filler all at once. It should be noted that after completing the first stage of mixing, half of the plasma-resistant composite filler can be added and mixed for 3-6 minutes at a temperature of 55-58℃ or 56-60℃ and a stirring speed of 45-48 rpm or 46-50 rpm; the other half of the plasma-resistant composite filler can be added and mixed for 3-6 minutes at a temperature of 55-58℃ or 56-60℃ and a stirring speed of 45-48 rpm or 46-50 rpm.

[0054] Furthermore, in step S4 above, after completing the second stage of mixing, the addition of fluorine-based low-temperature resistant plasticizer for the third stage of mixing includes: after completing the second stage of mixing, adding fluorine-based low-temperature resistant plasticizer and mixing at a stirring speed of 35~40 rpm for 2~4 minutes to complete the third stage of mixing.

[0055] Understandably, the fluorinated low-temperature resistant plasticizer in this embodiment is a compound of perfluoropolyether ester and fluoroalkylphosphonate, and its molecular structure is highly similar to the main chain structure of fluororubber raw rubber (-CF2-CF2- / -CF2-CF(CF3)-). However, the prerequisite for the plasticizer to function in the rubber matrix is ​​that it can be uniformly dispersed in the rubber molecular chains in a molecular state, increasing the free volume between chains and weakening the interchain forces. If the mixing process involves high temperature or excessive shear, the fluororubber molecular chains have increased mobility at high temperatures, and the plasticizer molecules may excessively penetrate into the molecular chains or become locally aggregated, thus disrupting the uniform distribution of the plasticizer in the matrix. At the end of the second stage of mixing, the rubber compound temperature has reached a relatively high range of 85~90℃. If the plasticizer is added directly at this temperature and high-shear mixing continues, the high-temperature environment will cause the fluororubber molecular chains to be in a highly active state, weakening the intermolecular interaction forces. Under high-speed shear, the plasticizer molecules may be unevenly distributed, with some areas having excessively high plasticizer concentrations and others having excessively low concentrations. Under high temperature conditions, the regular arrangement of fluororubber molecular chains may be disrupted, forming a disordered state. This disordering is difficult to fully recover during subsequent vulcanization, ultimately affecting the crosslinking network structure and mechanical properties of the vulcanized rubber.

[0056] It should be understood that in this embodiment, after adding the fluorinated low-temperature resistant plasticizer, the stirring speed is controlled at a low speed range of 35-40 rpm. This speed is much lower than the 45-50 rpm during the second stage of mixing, which can effectively reduce the shear heat generated during the mixing process, keep the rubber compound temperature at a low level, and avoid the disintegration of fluororubber molecular chains due to excessive shear heat. The mixing time is controlled within a short range of 2-4 minutes, which ensures that the plasticizer is initially evenly distributed in the rubber compound, while avoiding excessive dispersion or migration of the plasticizer due to prolonged mixing. Under these low-temperature, low-speed, and short-time mixing conditions, the plasticizer molecules enter the spaces between the fluororubber molecular chains in a relatively gentle manner, and are evenly distributed in the inter-chain regions while maintaining the original regularity of the molecular chain arrangement. This embodiment employs a third-stage mixing process after the second-stage mixing, ensuring that the fluorinated low-temperature resistant plasticizer is uniformly dispersed between the fluororubber molecular chains under mild conditions. This effectively avoids the problems of fluororubber molecular chain disintegration and uneven plasticizer distribution that may occur under high-temperature and high-shear conditions. As a result, the plasticizer can fully exert its role in increasing the free volume between chains and reducing the glass transition temperature during subsequent vulcanization, allowing the compound to maintain good chain segment mobility and elastic recovery performance at a low temperature of ~40℃.

[0057] Furthermore, in step S5 above, the mixture after the third stage of mixing is subjected to roll pressing to obtain masterbatch, and the vulcanizing agent and masterbatch are mixed and then compounded to obtain fluororubber compound, including: A roller pressing assembly is provided. After the third stage of mixing is completed, the glue is discharged at 85~90℃ to obtain the initial colloid. The colloid is rolled 4~5 times in the roller pressing assembly at a roller gap of less than 1mm and a roller temperature ≤50℃ to form the initial roller pressing sheet. The roller pressing sheet is left at room temperature for 10~12h to obtain the masterbatch. The masterbatch is added to the vulcanizing agent at 40~45℃ and mixed at a stirring speed of 35~40rpm for 2~4min. The temperature is then further heated from the discharge temperature of 40~45℃ to 75~80℃ to discharge the glue to form the colloid to be treated. The colloid to be treated is rolled 2~3 times in the roller pressing assembly at a roller gap of less than 2~3mm and a roller temperature ≤50℃ to form the roller pressing sheet to be treated. The roller pressing sheet to be treated is left at room temperature for 10~12h to obtain the fluororubber compound.

[0058] Understandably, in this embodiment, after the third stage of mixing, the rubber is discharged at 85-90°C to obtain the initial colloid. The initial colloid underwent three stages of mixing and two heating processes in the internal mixer. Under the influence of shear and temperature, the rubber molecular chains developed a certain degree of orientation and entanglement. The filler dispersion and the rubber matrix were also in a non-equilibrium state, resulting in residual internal stress within the colloid. If vulcanization is performed directly, the internal stress stored in the rubber compound will be released during subsequent processing or vulcanization, leading to unstable flow behavior, fluctuating vulcanization rates, and dimensional deviations or uneven performance of the final vulcanized rubber.

[0059] It should be understood that in this embodiment, the initial colloid is first subjected to a thin-pass treatment in a roller pressing assembly. The roller gap is set to be less than 1 mm and the roller temperature not exceeding 50°C. Under these conditions, the colloid is subjected to 4-5 thin-passes. The small roller gap allows the rubber compound to withstand greater shear deformation, forcing the rubber molecular chains to rearrange in the shear flow field. Simultaneously, it further opens and disperses any small filler agglomerates that may remain from the internal mixer mixing process. Controlling the roller temperature below 50°C avoids excessively high rubber compound temperatures due to mechanical shearing during the thin-pass process, preventing premature vulcanization before the addition of the vulcanizing agent. After the thin-pass process, the roller press sheet is left at room temperature for 10-12 hours. This resting process allows the internal molecular chains of the rubber compound to gradually relax, eliminating the orientation and residual stress introduced during the thin-pass process. Simultaneously, the filler and rubber molecular chains continue to undergo interfacial wetting and rearrangement without external force, forming a more stable interaction state, ultimately yielding the masterbatch.

[0060] Furthermore, in this embodiment, when adding the vulcanizing agent to the masterbatch, the mixing temperature is controlled at 40-45℃, the rotation speed at 35-40 rpm, and the mixing time at 2-4 minutes. This low-temperature condition effectively prevents the vulcanizing agent from prematurely decomposing due to excessively high temperatures during the mixing stage, avoiding localized cross-linking of the rubber compound before it is formed, and ensuring that the vulcanizing agent only undergoes physical dispersion without chemical reaction during mixing. After mixing, the rubber compound temperature is heated from 40-45℃ to 75-80℃ for degassing. This heating process reduces the viscosity of the rubber compound, facilitating the removal of air trapped during mixing, and simultaneously allowing the vulcanizing agent to be further evenly distributed in the rubber compound. The resulting rubber compound is then subjected to another thin-pass rolling process. This time, the roller gap is adjusted to 2-3 mm, the roller temperature does not exceed 50℃, and the thin-pass is performed 2-3 times. Compared to the small roller gap of the first thin-pass, a slightly larger roller gap is used in this stage to avoid excessive disturbance to the already formed vulcanizing agent distribution, while simultaneously ensuring that the rubber compound forms a sheet of uniform thickness. After the initial thin pass, the mixture is left to stand at room temperature for 10-12 hours to fully release residual stress within the final compound and to ensure uniform molecular-level distribution of the vulcanizing agent. After two thin passes and two extended standing periods, the Mooney viscosity of the compound will stabilize within a suitable processing range. Specifically, this embodiment utilizes two thin pass rolls to fully release residual stress within the compound.

[0061] It should be noted that the masterbatch can also be mixed with vulcanizing agent at temperatures of 40~44℃, 42~45℃ or 43~45℃, and at a stirring speed of 35~38rpm or 36~40rpm for 2~4 minutes.

[0062] To make the technical solution of the present invention clearer, the following detailed description is provided in conjunction with embodiments and comparative examples.

[0063] Example 1: The compound rubber comprises the following raw materials in parts: 100 parts of fluororubber raw rubber (FKM:FFKM=75:25, Mooney viscosity FKM=50, FFKM=60 respectively), 25 parts of plasma-resistant composite filler (SiC@SiO2: modified boron carbide=1:1), 5 parts of fluorine-based low-temperature resistant plasticizer (perfluoropolyether ester: fluoroalkylphosphonate=7:1), 4.5 parts of vulcanization system (tert-butylperoxyhexane: TAIC=1:1.3), and 5 parts of acid scavenger (magnesium oxide: calcium hydroxide=2:1). During the preparation of SiC@SiO2, ammonia was added to adjust the pH to 9.3; during the preparation of modified boron carbide, 3.5% by weight of boron nitride titanate coupling agent was added; after completion, 12.5 parts of the above SiC@SiO2 and 12.5 parts of modified boron carbide were taken. The compound rubber preparation process was carried out according to the above multi-stage mixing process. During vulcanization molding, the material is first initially vulcanized at 168℃, 19MPa, and 13min; then it undergoes secondary vulcanization in stages at 150℃ for 2h, 180℃ for 2h, and 220℃ for 3h to obtain the sealing material.

[0064] Example 2: Fluororubber raw rubber: Perfluorinated rubber raw rubber = 70:30 (Mounney viscosities are 50 and 65 respectively, with a difference of 15); Plasma-resistant composite filler SiC@SiO2: Modified boron carbide = 1:0.8. Other steps are the same as in Example 1.

[0065] Comparative Example 1: Plasma-resistant composite filler SiC@SiO2: modified boron carbide = 1:0.6, other steps are the same as in Example 1.

[0066] Comparative Example 2: No fluorinated low-temperature resistant plasticizer was added; other steps were the same as in Example 1.

[0067] The performance of the sealing materials obtained in the above embodiments and comparative examples was tested, and the results are shown in Table 1.

[0068] Table 1 Test results of mechanical and sealing properties

[0069] The fluororubber compounds in Examples 1 and 2 exhibit excellent overall performance. They have a tensile strength ≥22.5 MPa, elongation at break ≥238%, hardness 73~74 Shore A, compression set ≤15.2% at 200℃×70h, and Tg ≤-46℃, meeting the requirements for semiconductor seals.

[0070] In Comparative Example 1, due to the reduced proportion of modified boron carbide in the plasma-resistant composite filler, compared to Example 1, the number of covalent bond interfaces formed by coupling modification decreased, and the interfacial bonding force between the filler and the fluororubber matrix slightly decreased. This resulted in a decrease in tensile strength to 21.0 MPa, elongation at break to 225%, compression set to 19.0%, and low-molecular-weight volatiles to 0.42%. The plasma resistance also slightly decreased, indicating that the proportion of the plasma-resistant composite filler has a significant impact on the interfacial bonding force, plasma resistance, and overall mechanical properties of the material. In Comparative Example 2, due to the absence of a fluorinated low-temperature plasticizer, the low-temperature toughness of the compound decreased significantly, and the Tg increased to -28°C. It was prone to hardening at low temperatures and could not adapt to the wide temperature range conditions of semiconductors, proving that a fluorinated low-temperature plasticizer is key to improving the low-temperature sealing performance of the compound. It should be understood that this invention effectively improves technical defects such as high particle release rate, insufficient plasma resistance, poor wide temperature range sealing performance, and poor filler dispersibility and compatibility, providing a method for preparing high-performance materials for semiconductor sealing components.

[0071] Please combine Figure 1 and Figure 4 The second embodiment of the present invention also provides a fluororubber compound, wherein the raw materials for preparing the fluororubber compound include: 100 parts of fluororubber raw rubber, 20-30 parts of plasma-resistant composite filler, 4-6 parts of fluorine-based low-temperature resistant plasticizer, 4-5 parts of vulcanizing agent, and 4-6 parts of additives; the raw materials for the plasma-resistant composite filler include SiC@SiO2 composite filler and modified boron carbide; the mass ratio of SiC@SiO2 composite filler and modified boron carbide is 1:0.8-1.2.

[0072] Understandably, in this embodiment, SiC@SiO2 and modified boron nitride fillers form a composite interface layer in the rubber matrix that is synergistically reinforced by hydrogen bonds and covalent bonds. When the mass ratio of SiC@SiO2 composite filler to modified boron carbide is less than 1:0.8, the proportion of modified boron nitride is too low, the covalent bond interface effect is insufficient, and the strong bond between the filler and the rubber is difficult to guarantee, making the interface prone to damage under plasma bombardment. When the mass ratio is higher than 1:1.2, the proportion of modified boron nitride is too high. Although the covalent bond bonding is sufficient, the proportion of SiC@SiO2 is reduced, and the hydrogen bond network provided by the SiO2 shell is weakened, and the chemical inert shielding effect of the SiC core decreases, resulting in a weakened overall physical barrier capability of the filler against plasma. Controlling the ratio between 1:0.8 and 1.2 allows the hydrogen bond network and covalent bonds to bridge at the filler-rubber interface, forming a complementary and reinforced composite structure. The composite structure can effectively resist stress damage at the interface when subjected to plasma bombardment and wide-temperature thermal cycling, and inhibit the filler from peeling off from the rubber matrix, thereby achieving low particle release of fluororubber compound for semiconductor sealing from the material interface level.

[0073] Specifically, fluororubber raw rubber includes fluororubber and perfluorinated rubber, with a mass ratio of 70~80:20~30, wherein the difference in Mooney viscosity between fluororubber and perfluorinated rubber is ≤20; fluorinated low-temperature resistant plasticizers include perfluoropolyether esters and fluoroalkylphosphonates, with a mass ratio of 6~8:1; vulcanizing agents include 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, with a mass ratio of 1:1.2~1.5; additives include acid scavengers, processing aids, and antioxidants, wherein acid scavengers include magnesium oxide and calcium hydroxide, with a mass ratio of 2:1.

[0074] It should be understood that this embodiment, by limiting the formulation of the raw rubber system, plasticizer system, vulcanization system and acid scavenger system, achieves synergistic matching of the raw rubber system, plasticizer system, vulcanization system and acid scavenger system, so that the fluororubber compound has good low-temperature elasticity and high-temperature compression set resistance in a wide temperature range. The fluororubber compound prepared thus meets the harsh operating conditions of semiconductor processes from -40°C to 250°C.

[0075] Please combine Figure 1 and Figure 5 The third embodiment of the present invention provides a semiconductor sealing component, wherein at least a portion of the semiconductor sealing component is made of the aforementioned fluororubber compound.

[0076] Understandably, the semiconductor sealing assembly described in this embodiment is applied to process chambers, pipe connections, and valve opening and closing parts in semiconductor manufacturing processes involving plasma etching, deposition, and other steps. These parts are directly exposed to highly corrosive plasmas formed by NF3, ClF3, CF4, O2, etc., and simultaneously withstand wide-temperature thermal cycling from -40℃ to 250℃. The fluororubber compound provided in this embodiment, as the material for this assembly, has a core performance advantage in the synergistic effect of SiC@SiO2 and modified boron nitride in the plasma-resistant composite filler. The SiO2 shell surface of SiC@SiO2 is rich in Si-OH active sites, which can form a stable hydrogen bond network with the fluororubber molecular chain; the titanate coupling agent graft layer on the surface of the modified boron nitride forms a BO-Ti-Rub covalent bond bridging structure with the rubber crosslinking network during the vulcanization stage. The two form a composite interface layer in the rubber matrix that is synergistically enhanced by hydrogen bonds and covalent bonds, significantly improving the interfacial bonding strength between the filler and the matrix.

[0077] Specifically, when the sealing assembly is installed in a semiconductor process chamber, high-energy particles continuously bombard the surface of the assembly during plasma bombardment. If the bond between the filler and the rubber interface is weak, microcracks can easily form at the interface due to stress concentration, leading to the filler particles peeling off from the matrix and forming particulate matter that contaminates the wafer. In this embodiment, the SiC core itself possesses excellent chemical inertness and is not easily etched in fluorine- or oxygen-based plasma environments, effectively acting as a physical shielding layer to prevent high-energy particles from eroding the rubber matrix. The SiO2 shell on its surface forms extensive connections with the rubber matrix through hydrogen bonds, and the modified boron nitride forms a strong anchor with the rubber matrix through covalent bonds. Together, these two elements maintain a stable interfacial bond during plasma bombardment, preventing peeling off. Simultaneously, the sealing assembly has a wide temperature range sealing capability, meeting the requirements of a wide temperature range of -40℃ to 250℃. It should be understood that the semiconductor sealing assembly described in this embodiment uses fluororubber compound with dual interfacial bonding characteristics of hydrogen bonding and covalent bonding as material. In a plasma environment, it can effectively suppress the release of particles caused by the peeling of filler from the matrix, and maintain both low-temperature elasticity and high-temperature resistance to compression set under wide temperature range conditions.

[0078] The foregoing has provided a detailed description of a fluororubber compound, its preparation method, and a semiconductor sealing assembly disclosed in the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent substitutions, and improvements made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a fluororubber compound, characterized in that, The method includes; We provide SiC@SiO2 composite filler and modified boron carbide, and mix SiC@SiO2 and modified boron carbide to form a plasma-resistant composite filler; We provide fluororubber raw materials, vulcanizing agents, fluorine-based low-temperature resistant plasticizers and additives. After plasticizing the fluororubber raw materials, we mix them with the additives and carry out the first stage of compounding. After the first stage of mixing is completed, plasma-resistant composite filler is added for the second stage of mixing. After completing the second stage of mixing, continue to add fluorine-based low-temperature resistant plasticizers for the third stage of mixing; The mixture after the third stage of mixing is rolled to obtain masterbatch. The vulcanizing agent and masterbatch are mixed and then mixed to obtain fluororubber compound. In the fluororubber compound, SiC@SiO2 composite filler and modified boron carbide form hydrogen bonds with fluororubber, and modified boron carbide forms covalent bonds with fluororubber.

2. The method for preparing fluororubber compound as described in claim 1, characterized in that: We provide SiC@SiO2 composite fillers and modified boron carbide, wherein mixing SiC@SiO2 and modified boron carbide forms a plasma-resistant composite filler comprising: Silicon carbide, solvent, and tetraethyl orthosilicate are provided. Silicon carbide is dispersed in the solvent and ultrasonically treated for 20-30 min. Ammonia is added at a stirring rate of 100 r / min-200 r / min to obtain a mixture with a pH of 9.2-9.

5. Tetraethyl orthosilicate is added to the mixture and reacted at a constant temperature of 50-55℃ for 5-7 h. After the reaction is completed, the mixture is centrifuged and dried to obtain SiC@SiO2 composite filler. Boron nitride, a solvent, and a titanate coupling agent are provided. Boron nitride is dispersed in the solvent, and then the titanate coupling agent is added. The mixture is refluxed and stirred at 70-80°C for 3-4 hours to carry out the reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain modified boron nitride, wherein the mass fraction of the titanate coupling agent is 3-4 wt%. SiC@SiO2 and modified boron carbide were mixed at a mass ratio of 1:0.8~1.2 to form a plasma-resistant composite filler.

3. The method for preparing fluororubber compound as described in claim 1, characterized in that: We provide fluororubber raw materials, vulcanizing agents, fluorinated low-temperature plasticizers and additives, including: Fluororubber and perfluorinated rubber are provided. Fluororubber and perfluorinated rubber are mixed at a mass ratio of 70~80:20~30 to obtain fluororubber raw rubber, wherein the difference in Mooney viscosity between fluororubber and perfluorinated rubber is ≤20. Perfluoropolyether ester and fluoroalkylphosphonate are provided. Perfluoropolyether ester and fluoroalkylphosphonate are mixed at a mass ratio of 6~8:1 to obtain a fluorine-based low-temperature resistant plasticizer. A vulcanizing agent is obtained by mixing 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate at a mass ratio of 1:1.2~1.

5. The additives include acid scavengers, processing aids, and antioxidants. The acid scavengers include magnesium oxide and calcium hydroxide, with a mass ratio of magnesium oxide to calcium hydroxide of 2:

1.

4. The method for preparing fluororubber compound as described in claim 1, characterized in that: The process of plasticizing raw fluororubber and mixing it with additives, followed by the first stage of compounding, includes: Plasticize the raw fluororubber at 35-40 rpm for 2-4 minutes; After plasticizing, the plasticized fluororubber raw rubber and additives are mixed and kneaded at a temperature of 45~50℃ and a stirring speed of 30~35rpm for 2~4 minutes to complete the first stage of mixing.

5. The method for preparing fluororubber compound as described in claim 1, characterized in that: After the first stage of mixing is completed, the plasma-resistant composite filler is added for the second stage of mixing, which includes: The plasma-resistant composite filler is divided into two halves according to its components. After completing the first stage of mixing, one half of the plasma-resistant composite filler is added and mixed at a temperature of 55~60℃ and a stirring speed of 45~50rpm for 3~6 minutes. The other half of the plasma-resistant composite filler is added and mixed at a temperature of 55~60℃ and a stirring speed of 45~50rpm for 3~6 minutes. The temperature is then increased from 55~60℃ to 85~90℃ to complete the second stage of mixing.

6. The method for preparing fluororubber compound as described in claim 1, characterized in that: After completing the second stage of mixing, a third stage of mixing is carried out by adding fluorinated low-temperature resistant plasticizers, including: After completing the second stage of mixing, add the fluorinated low-temperature resistant plasticizer and mix at a stirring speed of 35~40 rpm for 2~4 minutes to complete the third stage of mixing.

7. The method for preparing fluororubber compound as described in claim 1, characterized in that: The mixture after the third stage of compounding is rolled to obtain masterbatch. The vulcanizing agent and masterbatch are then mixed and compounded to obtain fluororubber compound, which includes: A roller pressing assembly is provided. After the third stage of mixing is completed, the glue is discharged at 85~90℃ to obtain the initial colloid. The colloid is rolled 4~5 times in the roller pressing assembly at a roller gap of less than 1mm and a roller temperature of ≤50℃ to form the initial roller pressing sheet. The roller pressing sheet is placed at room temperature for 10~12h to obtain the masterbatch. Add vulcanizing agent to masterbatch at 40~45℃, mix at 35~40rpm for 2~4min, continue to heat the temperature from the discharge temperature of 40~45℃ to 75~80℃ to discharge the rubber and form the colloid to be treated. The colloid to be treated is rolled 2-3 times in the roller pressing assembly at a roller gap of less than 2-3 mm and a roller temperature of ≤50℃ to form a roll sheet to be treated. The roll sheet to be treated is left to stand at room temperature for 10-12 hours to obtain fluororubber compound.

8. A fluororubber compound, characterized in that: The raw materials for preparing the fluororubber compound include: 100 parts of fluororubber raw rubber, 20-30 parts of plasma-resistant composite filler, 4-6 parts of fluorine-based low-temperature resistant plasticizer, 4-5 parts of vulcanizing agent, and 4-6 parts of additives; the raw materials for the plasma-resistant composite filler include SiC@SiO2 composite filler and modified boron carbide; the mass ratio of SiC@SiO2 composite filler to modified boron carbide is 1:0.8-1.

2.

9. The fluororubber compound as described in claim 8, characterized in that: The fluororubber raw rubber includes fluororubber and perfluororubber, and the mass ratio of fluororubber to perfluororubber is 70~80:20~30, wherein the difference in Mooney viscosity between fluororubber and perfluororubber is ≤20. The fluorinated low-temperature resistant plasticizer includes perfluoropolyether ester and fluoroalkylphosphonate, wherein the mass ratio of perfluoropolyether ester to fluoroalkylphosphonate is 6~8:1; The vulcanizing agent comprises 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, wherein the mass ratio of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to triallyl isocyanurate is 1:1.2~1.5; The additives include acid absorbers, processing aids, and antioxidants, wherein the acid absorbers include magnesium oxide and calcium hydroxide in a mass ratio of 2:

1.

10. A semiconductor sealing assembly, characterized in that: At least a portion of the semiconductor sealing assembly is made of the fluororubber compound as described in claim 8 or 9.

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