High-performance rubber material for semiconductor sealing ring and preparation process of high-performance rubber material

Abstract

The invention belongs to the technical field of high polymer materials, and relates to a high-performance rubber material for a semiconductor sealing ring and a preparation process of the high-performance rubber material. The rubber material comprises the following components in parts by weight: 60-80 parts of a rubber base material, 10-15 parts of a toughening reinforcing agent, 15-20 parts of a copolymerization reinforcing agent, 9-11 parts of a heat conduction reinforcing agent, 8-10 parts of a conductive reinforcing agent, 4-6 parts of a stable modifier and 4-6 parts of a crosslinking bridging agent. The rubber base material is formed by compounding oil-resistant rubber and heat-resistant rubber, the heat-conducting and electric-conducting reinforcing agent is composed of multiphase ceramic and a carbon nanomaterial, and the crosslinking system is formed by combining a peroxide vulcanizing agent and an accelerant. The preparation process comprises the steps of mixing and pre-dispersing, closed kneading, main material open milling, mold pressing vulcanization and the like. The obtained material is high in thermal stability, small in compression deformation, low in metal ion precipitation and suitable for preparation of sealing ring products in high-cleanliness and high-temperature semiconductor manufacturing environments and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and relates to a high-performance rubber material for a semiconductor sealing ring and a preparation process thereof. Background Art

[0002] As semiconductor manufacturing technology develops towards higher precision and higher cleanliness, the performance requirements for various sealing components in process equipment are becoming increasingly stringent. Especially in high-temperature and highly corrosive environments such as plasma etching, chemical vapor deposition (CVD), and atomic layer deposition (ALD), the sealing rings must not only withstand strong ionization corrosion, but also ensure long-term sealing stability and extremely low risk of particle release.

[0003] At present, the sealing ring materials commonly used in semiconductor manufacturing equipment are mainly fluororubber (FKM), perfluororubber (FFKM), ethylene propylene diene monomer (EPDM), etc. Although FFKM materials are widely used in high-end processes due to their excellent chemical corrosion resistance and high temperature resistance, their high price, complex processing technology, poor resilience and other issues have limited their promotion. In contrast, although conventional fluororubber materials have certain corrosion resistance and thermal stability, they are prone to decomposition under the action of strong plasma and high-energy reactive gases, resulting in particle shedding or seal failure. In addition, the compatibility of different rubber matrices and fillers will also affect their overall physical properties, durability and plasma compatibility.

[0004] On the other hand, most current rubber sealing ring products are still formed using traditional high-temperature vulcanization or hot pressing methods. The compounding system is primarily designed around common fillers and crosslinking agents, lacking systematic optimization paths for plasma etching, low-metal contamination, or micro-contamination-sensitive processes. Existing preparation processes still have significant deficiencies in material purity control, inorganic filler dispersion, and heat treatment uniformity. This results in sealing rings experiencing high compression set, short residual life, and excessive degassing rates during actual use, making it difficult to meet the high reliability and low pollution requirements of advanced semiconductor manufacturing processes.

[0005] Therefore, how to develop a rubber material that has high temperature resistance, low outgassing properties, good mechanical properties and molding stability, and to build a set of high-purity molding processes suitable for the preparation of semiconductor sealing rings has become an important direction for technological improvement in this field. Summary of the Invention

[0006] In view of the above problems, the present invention aims to provide: a high-performance rubber material for semiconductor sealing rings, comprising the following raw materials in parts by weight: 60-80 parts of a rubber base material, 10-15 parts of a toughening enhancer, 15-20 parts of a copolymer enhancer, 9-11 parts of a thermal conductivity enhancer, 8-10 parts of a conductive enhancer, 4-6 parts of a stabilizing modifier, and 4-6 parts of a cross-linking agent;

[0007] The rubber base material includes: oil-resistant rubber and heat-resistant rubber, the oil-resistant rubber includes chloroprene rubber, butyl rubber or halogenated butyl rubber, the heat-resistant rubber includes silicone rubber, polysiloxane, fluorinated silicone rubber or fluorosilicone rubber, and the mass ratio of the oil-resistant rubber to the heat-resistant rubber is: (0.8-1.0): (3.2-3.5).

[0008] Furthermore, the toughening and reinforcing agent includes: natural rubber, butadiene rubber, crotyl alcohol, polyethylene glycol, carbon black, refined cotton and titanate coupling agent.

[0009] Furthermore, the chemical formula of the titanate coupling agent is: R1 n O-Ti-(O-R2) m-n According to the different lipophilic groups R1, the titanate coupling agent is at least one or more combinations of:

[0010] Among them, the first combination: R1 is an alcohol-containing group, including C7H 15 O, C3H6OH, C6H4OH and (C3H6OH)3, four types in total, n=1-3, m=4, R2 is C4H9;

[0011] The second combination: R1 is an amide-containing group, including C7H 15 CONH and C6H4NH2, two types in total, n = 1-2, m = 4, R2 is C2H5;

[0012] The third combination: R1 is an amino group, including C7H 15 OCH2CH2NH2, C3H6NH2 and C6H4CNH2, three types in total, n = 1-3, m = 4, R2 is C3H7;

[0013] The fourth combination: R1 is a phosphoric acid group: C3H6P(O)(OC2H5)2, n=1, m=4, R2=C3H7;

[0014] The titanate coupling agent is used in an amount of 0.1-0.3% of the total weight.

[0015] Furthermore, the copolymerization reinforcing agent includes: ethylene propylene diene monomer rubber, polyurethane rubber, butyl methacrylate, dioctyl phthalate and antimony trioxide.

[0016] Furthermore, the copolymer reinforcing agent is composed of the following components: 7-9 parts of EPDM rubber, 4-6 parts of polyurethane rubber, 2-3 parts of butyl methacrylate, 1 part of dioctyl phthalate, and 1 part of antimony trioxide.

[0017] Furthermore, the thermal conductivity enhancer includes: boron nitride, aluminum nitride and zinc oxide.

[0018] Further, the thermal conductivity enhancer includes, by weight parts: 3 - 4 parts of boron nitride, 3 - 4 parts of aluminum nitride, and 4 parts of zinc oxide.

[0019] Further, the electrical conductivity enhancer includes carbon nanotubes and graphene fibers.

[0020] Further, the electrical conductivity enhancer includes, by weight parts: 5 - 6 parts of carbon nanotubes and 3 - 4 parts of graphene fibers.

[0021] Further, the stability modifier includes phenolic antioxidants and amine antioxidants. The phenolic antioxidant is a substituted phenol, and the amine antioxidant is an arylenediamine and a ketone amine.

[0022] Further, the stability modifier includes, by weight parts: 2 - 3 parts of substituted phenol, 1 - 2 parts of arylenediamine, and 1 - 2 parts of ketone amine.

[0023] Further, the substituted phenol is 2,6 - bis(tert - butyl) - 4 - methylphenol and tris(3,5 - di - tert - butyl - 4 - hydroxyphenyl) phosphite.

[0024] Further, the arylenediamine and the ketone amine are mixed at a molar ratio of (1:1.5) - (1.5:1).

[0025] Further, the cross - linking agent includes a peroxide vulcanizing agent, an active cross - linking agent, an anti - scorching agent, and a vulcanization accelerator.

[0026] Further, the cross - linking agent includes, by weight parts: 1 part of peroxide vulcanizing agent, 1 - 2 parts of active cross - linking agent, 1 part of anti - scorching agent, and 2 parts of vulcanization accelerator.

[0027] Further, the peroxide vulcanizing agent is dicumyl peroxide, the active cross - linking agent is N,N' - ethylene thiourea, the anti - scorching agent is mercaptobenzothiazole, and the vulcanization accelerator is 2 - mercaptobenzothiazole.

[0028] The present invention also provides a preparation process of a high - performance rubber material for a semiconductor sealing ring, which is used to prepare the high - performance rubber material for a semiconductor sealing ring, and includes the following steps:

[0029] S1. Raw material mixing: Weigh all raw materials by weight parts. Place the copolymer enhancer, thermal conductivity enhancer, electrical conductivity enhancer, and stability modifier, and the copolymer enhancer and solid enhancer into a first pulverizer, add anhydrous ethanol, and stir and mix evenly to obtain a mixed powder.

[0030] S2. Toughening Copolymerization: Weigh the toughening and reinforcing agent and the rubber base material according to the weight ratio of 1:(5 - 10) of the mixed powder, place them in a kneader, and use closed - loop kneading. Control the kneading temperature at (85 ± 5)°C, the kneading time at 1 - 2 h, and the rotation speed at 16 - 20 r / min to obtain the toughening copolymer rubber;

[0031] S3. Masterbatch Mixing: Weigh the remaining rubber base material, crush it in a second crusher, and then put it into the hopper together with the remaining mixed powder for standby. Put the toughening copolymer rubber on the roller of an open mill and mix it by open - mill mixing method. At the same time, add the standby raw materials from the hopper, and control the material ratio: copolymer reinforcing agent: solid reinforcing agent: toughening and reinforcing agent: rubber base material as (80 - 100):(80 - 100):2:50;

[0032] S4. Vulcanization and Molding: Place the mixed rubber in an internal mixer, add a cross - linking agent for vulcanization, and then perform calendering molding to obtain the product.

[0033] Further, in the step S2, the closed - loop kneading includes pressure kneading, so that the internal pressure of the kneading chamber is 0.3 - 0.5 MPa.

[0034] Further, in the step S3, the temperature of the roller of the open mill is (60 ± 10)°C.

[0035] Further, in the step S4, the vulcanization temperature is 150 - 160°C, the vulcanization pressure is 30 - 35 Mpa, and the vulcanization time is 25 - 35 min.

[0036] Beneficial Effects

[0037] A high - performance rubber material for semiconductor sealing rings provided by the present invention, through the compound design of oil - resistant rubber and heat - resistant rubber, on the basis of ensuring the chemical corrosion resistance of the material, takes into account high - temperature stability and mechanical flexibility. The combination of the introduced toughening and reinforcing agent and copolymer reinforcing agent enables the material to have good compression - resilience performance and structural stability under the condition of cross - linking density control.

[0038] The heat - conducting reinforcing agent and the conductive reinforcing agent are further introduced into the material system. Through the multi - phase filler to form a composite filling structure, while maintaining the dielectric uniformity of the material, the regulation of interface thermal conductivity and carrier - flow channel structure is realized. The adopted combination of stabilizing modifiers includes substituted phenols, aromatic amines and ketoamines, which is suitable for inhibiting free - radical reactions during high - temperature aging and improving the long - term stability of the material.

[0039] In terms of the preparation process, the present invention enables various functional components to be evenly distributed in the system by setting up the dispersion of mixed powder, closed-loop kneading, masterbatch mixing, and multi-stage feeding control. By using a combination of peroxide vulcanizing agents and accelerators to synergistically construct a crosslinking network, the crosslinking efficiency and processing stability of the rubber compound are improved, meeting the requirements of high-precision compression molding and sheet extrusion molding processes.

[0040] The material of the present invention is applicable to the sealing environment exposed to plasma gas, strongly corrosive media, and high heat load conditions during the semiconductor manufacturing process, meeting the basic performance requirements for high cleanliness, low outgassing, and high-temperature resistant sealing products. Brief Description of the Drawings

[0041] Figure 1 It is a schematic diagram of the comparative experiment results (T5% temperature) of the present invention;

[0042] Figure 2 It is a schematic diagram of the comparative experiment results (residual carbon rate) of the present invention;

[0043] Figure 3 It is a schematic diagram of the comparative experiment results (compression set rate) of the present invention;

[0044] Figure 4 It is a schematic diagram of the comparative experiment results (total outgassing amount) of the present invention. Detailed Description of the Embodiments

[0045] To deepen the understanding of the present invention, the following will further elaborate on the present invention in combination with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation to the protection scope of the present invention.

[0046] Embodiment 1

[0047] This embodiment provides a high-performance rubber material for semiconductor sealing rings and its preparation process. The components and operating parameters are as follows:

[0048] Raw material composition (by weight):

[0049] Rubber base material: 20 parts of chloroprene rubber, 60 parts of fluorosilicone rubber (mass ratio 1:3);

[0050] Toughening and reinforcing agent: 2 parts of natural rubber, 3 parts of cis-butadiene rubber, 1 part of crotyl alcohol, 2 parts of polyethylene glycol, 4 parts of carbon black, 1 part of refined cotton, 0.3 part of titanate coupling agent;

[0051] Copolymer reinforcing agent: 8 parts of ethylene-propylene-diene monomer rubber, 5 parts of polyurethane rubber, 2 parts of butyl methacrylate, 1 part of dioctyl phthalate, 1 part of antimony trioxide;

[0052] Thermal conductivity enhancing agent: 3 parts of boron nitride, 3 parts of aluminum nitride, 4 parts of zinc oxide

[0053] Conductive enhancer: 6 parts of carbon nanotubes, 4 parts of graphene fibers

[0054] Stabilizing modifier: 2 parts of 2,6-bis(tert-butyl)-4-methylphenol, 1 part of tris(3,5-di-tert-butyl-4-hydroxyphenyl) phosphite, 1 part of arylenediamine, 1 part of ketoamine (molar ratio 1:1).

[0055] Crosslinking bridging agent: 1 part of dicumyl peroxide, 2 parts of N,N'-ethylene thiourea, 1 part of mercaptobenzimidazole, 2 parts of 2-mercaptobenzothiazole

[0056] Preparation process

[0057] Step S1: Raw material mixing: Put a total of about 45 parts of the above copolymer enhancer, thermal conductivity enhancer, conductive enhancer and stabilizing modifier into a pulverizing mixer, add 200 mL of absolute ethanol, and stir and mix for 30 minutes to obtain a uniformly mixed powder.

[0058] Step S2: Toughening copolymerization: Blend the mixed powder with a rubber base material (80 parts) and a toughening and strengthening agent (10 parts) at a weight ratio of 1:6, put them into a closed kneader, control the kneading temperature at 85±5°C, the pressure at 0.4 MPa, the rotation speed at 18 r / min, and the kneading time at 1.5 hours to obtain a toughened copolymer rubber.

[0059] Step S3: Masterbatch mixing: Crush the remaining rubber base material (10 parts) in a crusher for standby; Place the toughened copolymer rubber in the roller of an open mill (temperature set at 65°C), and add the mixed powder and the remaining rubber base material while rolling; During the mixing process, control the total material ratio: copolymer enhancer: solid enhancer: toughening enhancer: rubber base material is 90:90:2:50, the roll gap is 5 mm, and mix for 15 minutes.

[0060] Step S4: Vulcanization molding: Put the mixed rubber into a mixer, add a total of 6 parts of crosslinking bridging agent, and the mixing time is 10 minutes; Then send it to a compression molding device, set the temperature at 155°C, the pressure at 32 MPa, and the vulcanization time at 30 minutes. Demold to obtain a high-performance sealing ring sample with a thickness of 3 mm and a diameter of 100 mm.

[0061] Example 2

[0062] This example provides another high-performance rubber material for semiconductor sealing rings and its preparation process. The components and operating parameters are as follows:

[0063] Raw material composition (by weight):

[0064] Rubber base material: 18 parts of butyl rubber, 62 parts of fluorosilicone rubber (mass ratio is about 0.9:3.1);

[0065] Toughening and strengthening agent: 1 part of natural rubber, 1 part of crotyl alcohol, 5 parts of carbon black, 0.2 part of titanate coupling agent (without using polyethylene glycol and refined cotton);

[0066] Copolymerization strengthening agent: 9 parts of ethylene propylene diene monomer rubber, 6 parts of polyurethane rubber, 2.5 parts of butyl methacrylate, 1 part of dioctyl phthalate, 1 part of antimony trioxide;

[0067] Thermal conductivity strengthening agent: 4 parts of boron nitride, 3 parts of aluminum nitride, 3 parts of zinc oxide;

[0068] Conductive strengthening agent: 5 parts of carbon nanotubes, 3 parts of graphene fibers;

[0069] Stabilizing modifier: 2 parts of 2,6-bis(tert-butyl)-4-methylphenol, 1.5 parts of arylenediamine, 1 part of ketoamine (molar ratio 1.5:1);

[0070] Crosslinking agent: 1 part of dicumyl peroxide, 1 part of N,N'-ethylene thiourea, 1 part of scorch retarder mercaptobenzothiazole, 2 parts of 2-mercaptobenzothiazole;

[0071] Preparation process

[0072] Step S1: Raw material mixing:

[0073] Put the copolymerization strengthening agent, thermal conductivity strengthening agent, conductive strengthening agent and stabilizing modifier (about 43 parts in total) into a high-speed mixer, add 150 mL of absolute ethanol, and stir and mix for 20 minutes to obtain a uniformly mixed powder.

[0074] Step S2: Toughening copolymerization:

[0075] Mix the above mixed powder with the rubber base material (80 parts) and the toughening and strengthening agent (7.2 parts in total) at a weight ratio of 1:7, put them into a closed kneader, set the kneading temperature at 90 °C, control the pressure in the cavity at 0.3 MPa, the rotation speed at 20 r / min, and the kneading time at 1 hour to obtain the toughened copolymer rubber.

[0076] Step S3: Masterbatch mixing:

[0077] Crush the remaining fluorosilicone rubber (about 8 parts) for standby; put the toughened copolymer rubber into a temperature-controlled open mill, set the roller temperature at 60 °C, and sequentially add the remaining rubber base material and the mixed powder while rolling. The total material ratio is controlled as copolymerization strengthening agent: solid strengthening agent: toughening and strengthening agent: rubber base material = 100:90:2:50, and the mixing time is controlled within 20 minutes.

[0078] Step S4: Vulcanization and molding:

[0079] Put the kneaded rubber into a Banbury mixer, add a total of 5 parts of crosslinking agent, and the mixing time is 10 minutes. Then use a hot press molding device for molding. The vulcanization temperature is 160 °C, the pressure is 33 MPa, and the time is set to 28 minutes. After demolding, the target sealing ring sheet is obtained.

[0080] Comparative experiment

[0081] Comparative Example 1 (Comparative example of technical solution)

[0082] This comparative example is used to verify the structural contribution of the thermal conductivity enhancer in the rubber system.

[0083] Raw material composition (by weight):

[0084] Rubber base material: 20 parts of chloroprene rubber, 60 parts of fluorosilicone rubber;

[0085] Toughening and strengthening agent: 2 parts of natural rubber, 3 parts of cis-butadiene rubber, 1 part of crotyl alcohol, 2 parts of polyethylene glycol, 4 parts of carbon black, 1 part of refined cotton, 0.3 part of titanate coupling agent;

[0086] Copolymerization strengthening agent: 8 parts of ethylene propylene diene monomer rubber, 5 parts of polyurethane rubber, 2 parts of butyl methacrylate, 1 part of dioctyl phthalate, 1 part of antimony trioxide;

[0087] Thermal conductivity enhancer: not added;

[0088] Conductive enhancer: 6 parts of carbon nanotubes, 4 parts of graphene fibers;

[0089] Stable modifier: 2 parts of 2,6-bis(tert-butyl)-4-methylphenol, 1 part of arylenediamine, 1 part of ketoamine (molar ratio 1:1);

[0090] Crosslinking agent: 1 part of dicumyl peroxide, 2 parts of N,N'-ethylene thiourea, 1 part of mercaptobenzimidazole, 2 parts of 2-mercaptobenzothiazole.

[0091] Preparation process

[0092] Step S1: Premixing of raw materials:

[0093] Weigh carbon black, carbon nanotubes, graphene fibers, ethylene propylene diene monomer rubber, polyurethane rubber, butyl methacrylate, dioctyl phthalate, antimony trioxide, antioxidant combination (substituted phenols, arylamines, ketoamines), crotyl alcohol, cis-butadiene rubber, natural rubber, refined cotton, polyethylene glycol, and titanate coupling agent in sequence, put them into a planetary high-speed mixer, add 150 mL of absolute ethanol as a dispersion carrier, and stir and mix at 200 rpm for 25 minutes to make the filler and modifier evenly coated and combined to obtain a gray-black mixed powder.

[0094] Step S2: Toughening copolymer mixing:

[0095] 80 parts of the mixed powder, 20 parts of chloroprene rubber, and 60 parts of fluorosilicone rubber are added together as the base material to a closed kneader (using a front-opening kneading system). The initial temperature is set at 85 °C, and after heating, it is maintained in the range of 85 ± 2 °C. The cavity pressure is set at 0.4 MPa, the kneading speed is set at 18 r / min, and the kneading time is 1.5 hours. No air is introduced during the process to avoid oxidative aging, and a uniform composite toughened rubber compound is obtained.

[0096] Step S3: Masterbatch mixing:

[0097] 8 parts of the remaining fluorosilicone rubber are crushed into particles with a size of 5 - 8 mm using a low-speed toothed crusher and reserved. The aforementioned toughened rubber compound is put into an open mill. The roller temperature is set at 65 °C, and the roller gap is 5 mm. The crushed rubber particles and the remaining mixed powder are synchronously added in portions from the feeding port at intervals of 2 minutes. While rolling, the material distribution is adjusted, and the mixing time is controlled within 20 minutes to ensure that the softness and uniformity of the rubber compound are consistent.

[0098] Step S4: Vulcanization and molding:

[0099] The kneaded rubber compound is cut into strips and then put into an internal mixer for secondary heat mixing. Crosslinking agents such as dicumyl peroxide, N,N'-ethylene thiourea, mercaptobenzimidazole, and 2-mercaptobenzothiazole are added. The internal mixing temperature is maintained at 90 °C, and the mixing time is 10 minutes. After discharging, it is immediately loaded into a sealed mold and vulcanized and molded in a vacuum molding press. The molding temperature is set at 155 °C, the pressure is 32 MPa, and the vulcanization holding time is 30 minutes. After natural cooling, it is demolded to obtain the test seal ring sheet.

[0100] Comparative Example 2 (Comparative example of technical solution)

[0101] This comparative example is used to verify the technical advantages of the multi-component rubber base material system, the conductive filler structure, and the peroxide crosslinking process.

[0102] Raw material composition (by weight parts):

[0103] Rubber base material: 100 parts of ethylene propylene diene monomer (EPDM);

[0104] Toughening and reinforcing agent: 8 parts of carbon black, 12 parts of light calcium carbonate;

[0105] Thermal conductivity enhancing agent: 3 parts of zinc oxide;

[0106] Stabilizing and modifying agent: 1.5 parts of aromatic amine antioxidant;

[0107] Crosslinking system: 2 parts of sulfur, 1 part of accelerator TMTD, 1.5 parts of accelerator MBTS, 0.5 part of scorch retarder C, 1 part of stearic acid;

[0108] Preparation process

[0109] Step S1: Base material plasticization and filler addition:

[0110] Cut the EPDM film into strips with a width of 2 - 4 cm, add it to an open mill (roll gap is 3 mm), control the starting temperature at room temperature, after 5 minutes of plasticization, add carbon black and calcium carbonate in sequence, and roll and mix for 10 minutes until the surface of the material is smooth.

[0111] Step S2: Auxiliary agent mixing:

[0112] Add antioxidant, zinc oxide, and stearic acid to the plasticized rubber and continue mixing. Gradually add sulfur, accelerator TMTD, MBTS, and scorch retarder C, and mix for 8 minutes until the rubber compound is evenly dispersed, then stop the machine and take it out. Control the thickness of the film at 3 mm and let it stand at room temperature for 2 hours.

[0113] Step S3: Mold pressing and vulcanization:

[0114] After cutting the film, place it in a standard flat plate vulcanization mold and perform hot pressing and forming on a vulcanizing machine. Set the temperature at 160 °C, the pressure at 18 MPa, and the vulcanization time at 20 minutes. After demolding and cooling, obtain a sealing ring sample with a thickness controlled at 2.5 mm.

[0115] Comparative Example 3 (Comparative example of the prior art)

[0116] This comparative example refers to the common commercial fluororubber sealing ring formula in current semiconductor equipment, does not introduce enhanced structures such as high thermal conductivity, high electrical conductivity, and multi-stage cross-linking systems, and the process flow also adopts the traditional open mill + conventional vulcanization method, serving as the basic reference group for the solution of the present invention.

[0117] Raw material composition (by weight parts):

[0118] Rubber base material: Fluororubber 100 parts;

[0119] Filler system: 10 parts of carbon black, 1 part of stearic acid;

[0120] Processing aids: 2 parts of paraffin oil, 1 part of graphite;

[0121] Stabilizer: 1 part of hindered phenol antioxidant;

[0122] Vulcanization system: 2 parts of dicumyl peroxide, 2 parts of triazine cross-linking agent, 2 parts of magnesium oxide, 5 parts of silicon dioxide.

[0123] Preparation process

[0124] Step S1: Premixing in an open mill:

[0125] Add 100 parts of fluororubber ( Type B) After cutting into strips, put them into an open mill (the distance between the two rollers is set to 4 mm), and carry out basic plasticization at room temperature starting state. After the viscoelasticity of the rubber material decreases, add 10 parts of carbon black, 2 parts of paraffin oil, 1 part of graphite, and 1 part of stearic acid in sequence. After adding each kind of powder material, roll for 5 minutes, and continue to add the next component after there are no agglomerated particles on the surface.

[0126] Step S2: Crosslinking system mixing:

[0127] On the basis of the gradually uniform rubber compound, add 2 parts of dicumyl peroxide, 2 parts of triazine crosslinking agent, 2 parts of magnesium oxide, and 5 parts of silicon dioxide. Continue to roll for 10 minutes, and keep the mixing temperature between room temperature and 60 °C. After mixing is completed, stop the operation, adjust the thickness of the film to 2 mm, wrap it with a PE film for standby, and let it stand at room temperature for more than 4 hours to release stress.

[0128] Step S3: Mold pressing and vulcanization:

[0129] Cut the film into dimensions matching the mold cavity, and put it into a standard flat vulcanizer for mold pressing. The mold pressing temperature is set to 170 °C, the vulcanization pressure is 20 MPa, and the pressure holding time is 20 minutes. Then demold and cool naturally to room temperature. The obtained sample has a thickness of 3 mm and can be used for the basic test of the sealing ring performance.

[0130] Test conditions and test items

[0131] Test condition setting: The test is carried out in a temperature-controlled laboratory, the ambient temperature is 23 ± 2 °C, and the relative humidity is controlled at 50 ± 5%. All samples need to be pretreated before testing, that is, dried in a vacuum drying oven at 60 °C for 12 hours to remove the volatile residues in the material to ensure the accuracy and consistency of the test results. The sample specifications are uniformly prepared into sealing rings with a thickness of 3 mm and a diameter of 80 mm.

[0132] Test items:

[0133] 1. Thermal stability test: Use a thermogravimetric analyzer (TGA) for testing. The test atmosphere is nitrogen, the flow rate is 60 mL / min, the heating rate is set to 10 °C / min, and heat from room temperature to 800 °C. Record the 5% mass loss temperature (T5%) of the material and the char residue rate at 800 °C, which are used to evaluate the stability at the initial stage of thermal decomposition and the stability of the residue at high temperature.

[0134] 2. Compression set test: According to the GB / T 7759 or ASTM D395 standard, select a cylindrical sample with Φ29 mm × 12.5 mm, compress it at 25% compression amount at 200 °C for 70 hours, release it and place it at 23 °C for 30 minutes, measure its thickness change, and calculate the compression set rate to reflect the resilience ability of the material under hot pressing and sealing conditions.

[0135] 3. Volatile matter evolution test (total evolved gas volume): According to the semiconductor material cleanliness standard (such as SCCS standard or referring to ISO14644), place the sample in a clean vacuum chamber, hold it at 150 °C for 2 hours, and use a micro gas capture system to record the total mass of volatile matter per unit area, with the unit of μg / cm 2 . It is used to evaluate whether the material is likely to generate contaminant particles or gases in a high-temperature chamber.

[0136] 4. Ion migration element evolution test: Immerse the sample in ultrapure water or a hydrofluoric acid dilution solution, take it out after heat treatment at a constant temperature of 85 °C for 24 hours, and use an inductively coupled plasma optical emission spectrometer (ICP-OES) to analyze the contents of trace ions such as Na + , K + , Ca 2+ , Fe 3+ , Cl-, F-, etc., to judge the risk of metal impurity evolution of the material.

[0137] Test results

[0138] To verify the applicability of the high-performance rubber material of the present invention in semiconductor sealing rings, Example 1, Example 2, and Comparative Example 1 (removing the heat-conducting enhancer), Comparative Example 2 (conventional EPDM formulation), and Comparative Example 3 (traditional fluororubber solution) were respectively selected for key performance tests. The test items included thermogravimetric analysis (TGA), compression set rate, total evolved gas volume, and metal ion evolution concentration. The test results of each item are shown in Table 1 below:

[0139] Table 1 Test results of comparative experiments

[0140]

[0141] As Figure 1 shown, from the results of thermogravimetric analysis (TGA), the 5% thermal weight loss temperatures (T5%) of Example 1 and Example 2 were 233 °C and 238 °C respectively, both higher than those of Comparative Example 1 (210 °C) and Comparative Examples 2 and 3 (193 °C and 172 °C), indicating that the formulation system of the present invention has stronger thermal stability in terms of structural design. This advantage can be attributed to the introduction of fluorosilicone rubber, silicone rubber and their compound structures with high thermal stability in the rubber matrix, and at the same time supplemented with synergistically enhanced nano-scale fillers (such as boron nitride, aluminum nitride) to form a multi-phase thermal barrier in the system and delay the thermal decomposition starting point. In contrast, Comparative Example 3 only uses a single EPDM as the base material and does not configure structurally stable fillers, with early thermal decomposition and low char residue rate, indicating that it does not meet the conditions for long-term use in a high-temperature chamber.

[0142] As Figure 2As shown, in terms of the compression set performance, the deformation rate of the examples is controlled below 16%, much lower than that of traditional rubber materials. This result indicates that the rubber material of the present invention has high thermal resilience and good structural recovery ability, and is suitable for sealing applications under long-term compressive stress. The realization of this performance benefits from the multi-crosslinking bridge system (including peroxide vulcanizing agent, mercapto accelerator and active crosslinking agent) adopted in the formulation, which can establish a uniformly distributed crosslinking network in different temperature ranges and improve the compression creep resistance of the system. In contrast, Comparative Examples 2 and 3 use the traditional sulfur / carbon black vulcanization system or do not adopt a distributed crosslinking agent, and the crosslinking structure is unstable, and the compression set rate is easily increased due to thermal aging, thereby reducing the sealing performance.

[0143] As Figure 3 shown, in the total gas release test, the release of the example samples is controlled below 6 μg / cm 2 2, which is significantly better than all comparative examples, reflecting the full adaptation of the material of the present invention to cleanliness. This advantage is attributed to two aspects: one is that the present invention avoids low-molecular-weight migrates and volatile plasticizers in material selection, and the other is that free small molecules are effectively removed through high-temperature drying and vacuum treatment processes during the preparation process, so that the material is not likely to release harmful gases under high-temperature vacuum conditions, meeting the requirements for residue control in semiconductor clean rooms. In contrast, Comparative Examples 2 and 3 use ordinary fillers and conventional rubber processing systems, contain a certain amount of low-molecular-weight plasticizers and volatile by-products, and show a high gas release level in the test, posing a pollution risk.

[0144] As Figure 4 shown, in the metal ion migration test, the release concentrations of trace metal ions such as Na + , K + , Ca 2+ in the example materials are lower than 10 ppb, much lower than the 30-50 ppb level of the comparative examples. This is attributed to the high-purification treatment of the fillers (such as carbon black, thermally conductive ceramics, graphene fibers, etc.) in the examples, and the surface metal residues are sealed by titanate coupling agents, while avoiding the use of traditional metal oxides as auxiliaries, controlling the migration channels of metal impurities from the source. In contrast, there are metal ion residues in the auxiliaries such as magnesium oxide, silicon dioxide, and vulcanization accelerator used in Comparative Example 2, and their precipitation values far exceed the cleanliness standard, significantly increasing the risk of ionic contamination of the semiconductor structure, which may cause process corrosion or product defects.

[0145] Generally speaking, through the design of composite rubber matrix, the synergistic compounding of reinforcing phases, the introduction of high-purity filler system and the control of multi-stage crosslinking process, the material system proposed by the present invention systematically solves a number of core problems such as high-temperature sealing stability, compression set, clean volatilization and metal precipitation, and shows stable, reliable and better comprehensive performance than the prior art in the test results, fully meeting the high-standard application requirements of the semiconductor manufacturing environment for sealing materials.

[0146] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A high-performance rubber material for semiconductor sealing rings, characterized in that, It includes the following raw material components by weight parts: 60 - 80 parts of rubber base material, 10 - 15 parts of toughening and reinforcing agent, 15 - 20 parts of copolymer reinforcing agent, 9 - 11 parts of thermal conductivity reinforcing agent, 8 - 10 parts of electrical conductivity reinforcing agent, 4 - 6 parts of stabilizing modifier, 4 - 6 parts of crosslinking bridging agent; The rubber base material includes: oil - resistant rubber and heat - resistant rubber. The oil - resistant rubber includes chloroprene rubber, butyl rubber or halogenated butyl rubber. The heat - resistant rubber includes silicone rubber, polysiloxane, fluorinated silicone rubber or fluoro - silicone rubber, and the mass ratio of the oil - resistant rubber to the heat - resistant rubber is: (0.8 - 1.0):(3.2 - 3.5).

2. The high-performance rubber material for semiconductor sealing rings according to claim 1, wherein: The toughening and reinforcing agent includes: natural rubber, cis - butadiene rubber, crotyl alcohol, polyethylene glycol, carbon black, refined cotton and titanate coupling agent.

3. The high-performance rubber material for a semiconductor sealing ring according to claim 2, wherein: The chemical formula of the titanate coupling agent is: R1 n O-Ti-(O-R2) m-n , and according to the difference of the lipophilic group R1, the titanate coupling agent is at least one or a combination of multiple kinds: Among them, the first combination: R1 is an alcohol-containing group, including C7H 15 O, C3H6OH, C6H4OH, and (C3H6OH)3, a total of four kinds, n = 1-3, m = 4, and R2 is C4H9; Second combination: R1 contains an amide group, including C7H 15 CONH and C6H4NH2, two in total, n = 1 - 2, m = 4, and R2 is C2H5; Third combination: R1 is an amino group-containing group, including C7H 15 OCH2CH2NH2, C3H6NH2, and C6H4CNH2, a total of three kinds, n = 1 - 3, m = 4, R2 is C3H7; The fourth combination: R1 is a phosphoric acid - containing group: C3H6P(O)(OC2H5)2, n = 1, m = 4, R2 = C3H7; The dosage of the titanate coupling agent is 0.1 - 0.3% of the total weight.

4. A high-performance rubber material for semiconductor sealing rings according to claim 1, characterized in that: The copolymer reinforcing agent is composed of the following components: 7 - 9 parts of ethylene - propylene - diene monomer rubber, 4 - 6 parts of polyurethane rubber, 2 - 3 parts of butyl methacrylate, 1 part of dioctyl phthalate, 1 part of antimony trioxide.

5. A high-performance rubber material for semiconductor sealing rings according to claim 1, characterized in that: The thermal conductivity reinforcing agent by weight parts includes: 3 - 4 parts of boron nitride, 3 - 4 parts of aluminum nitride, 4 parts of zinc oxide.

6. A high-performance rubber material for semiconductor sealing rings according to claim 1, characterized in that: The electrical conductivity reinforcing agent by weight parts includes: 5 - 6 parts of carbon nanotubes and 3 - 4 parts of graphene fibers.

7. A high-performance rubber material for semiconductor sealing rings according to claim 1, characterized in that: The stabilizing modifier includes phenolic antioxidants and amine antioxidants. The phenolic antioxidant is a substituted phenol, and the amine antioxidant is arylenediamine and ketoamine; by weight parts, it includes: 2 - 3 parts of substituted phenol, 1 - 2 parts of arylenediamine, 1 - 2 parts of ketoamine.

8. A high-performance rubber material for semiconductor sealing rings according to claim 1, characterized in that: The crosslinking bridging agent by weight parts includes: 1 part of peroxide vulcanizing agent, 1 - 2 parts of active crosslinking agent, 1 part of scorch retarder, 2 parts of vulcanization accelerator; the peroxide vulcanizing agent is dicumyl peroxide, the active crosslinking agent is N,N'-ethylenethiourea, the scorch retarder is mercaptobenzothiazole, and the vulcanization accelerator is 2 - mercaptobenzothiazole.

9. A preparation process of a high-performance rubber material for semiconductor sealing rings, which is used to prepare the high-performance rubber material for semiconductor sealing rings as described in any one of claims 1-8, characterized in that, It includes the following steps: S1. Raw material mixing: Weigh all raw materials by weight parts. Put the copolymer reinforcing agent, thermal conductivity reinforcing agent, electrical conductivity reinforcing agent and stabilizing modifier, and the copolymer reinforcing agent and solid reinforcing agent into the first pulverizer, add anhydrous ethanol, stir and mix evenly to obtain mixed powder; S2. Toughening copolymerization: Weigh the toughening and reinforcing agent and rubber base material according to the weight ratio of 1:(5 - 10) of the mixed powder, put them into a kneader, adopt closed - loop kneading, control the kneading temperature at (85±5)°C, control the kneading time at 1 - 2 h, and control the rotation speed at 16 - 20 r / min to obtain toughened copolymer rubber; S3. Masterbatch mixing: Weigh the remaining rubber base material, crush it in the second crusher, and then put it into the hopper together with the remaining mixed powder for standby. Put the toughened copolymer rubber on the rollers of the open mill, and carry out mixing by the open mill method. At the same time, add the standby raw materials from the hopper, and control the material ratio: copolymer reinforcing agent: solid reinforcing agent: toughening reinforcing agent: rubber base material is (80 - 100):(80 - 100):2:50; S4. Vulcanization and molding: Place the mixed rubber in an internal mixer, add a cross-linking agent for vulcanization, and then carry out calendering molding to obtain the product.

10. The preparation process of a high-performance rubber material for semiconductor sealing rings according to claim 9, characterized in that: In the step S2, the closed-loop kneading includes pressure kneading, and the internal pressure of the kneading chamber is 0.3 - 0.5 Mpa; In the step S3, the temperature of the rollers of the open mill is (60 ± 10) °C; In the step S4, the vulcanization temperature is 150 - 160 °C, the vulcanization pressure is 30 - 35 Mpa, and the vulcanization time is 25 - 35 min.

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