Epoxy resin-nano cerium oxide composite polishing liquid and preparation method thereof

Abstract

The application discloses an epoxy resin-nano cerium oxide composite polishing liquid and a preparation method thereof. The epoxy resin-nano cerium oxide composite polishing liquid comprises the following components in parts by weight: 10-25 parts of water-based epoxy resin, 3-5 parts of modified epoxy resin, 15-30 parts of nano cerium oxide, 20-40 parts of water, 10-20 parts of ethanol, 2-5 parts of a dispersing agent, 1-3 parts of a surfactant, 0.5-2 parts of a stabilizing agent, 0.1-0.5 parts of polydimethylsiloxane and 0.3-1 part of a preservative. The modified epoxy resin is prepared by modification of a silane coupling agent, tris(4-carboxyphenyl) imidazole and fulvic acid. The preparation method is completed through the steps of preparing a solvent system, dispersing nano cerium oxide and composite grinding. The method can strengthen the interfacial bonding force, inhibit the abrasive aggregation, improve the dispersion stability, polishing performance and storage durability of the polishing liquid, and reduce the surface roughness of a workpiece, and is suitable for precision machining of optical elements, semiconductor wafers and the like, and meets the needs of high-end manufacturing ultra-precision polishing.

Description

Technical Field

[0001] This invention belongs to the field of polishing fluid technology, and particularly relates to an epoxy resin-nano cerium oxide composite polishing fluid and its preparation method. Background Technology

[0002] Polishing slurry is a core functional medium in precision machining, used to achieve surface smoothness and brightness of workpieces. Through the synergistic effect of mechanical grinding and chemical etching, it removes defects such as micro-protrusions and scratches from the workpiece surface, reducing surface roughness and ultimately achieving the required smoothness and flatness. As a key consumable in the polishing process, the performance of polishing slurry directly determines the machining accuracy, surface quality, and production efficiency of the workpiece. It is widely applicable to many high-end manufacturing fields such as semiconductor manufacturing, optical component processing, precision instrument assembly, and automotive parts polishing, and is an important support for the development of modern manufacturing towards high precision and high integration.

[0003] From the perspective of composition and mechanism of action, polishing slurries are typically formulated from nano-sized abrasives, solvents, dispersants, surfactants, and functional additives (such as stabilizers and preservatives). Among these, abrasives are the core component that determines polishing efficiency and surface quality; their hardness, particle size, and dispersion stability directly affect the polishing effect. Currently, the mainstream abrasive types include cerium oxide, alumina, silica sol, and nanodiamonds. Among these, nano-cerium oxide, with its unique physicochemical properties, has become the preferred abrasive for polishing precision workpieces such as optical glass and semiconductor wafers. It has moderate hardness, enabling efficient cutting without scratching the substrate; excellent chemical activity, allowing it to undergo a weak chemical reaction with the substrate surface to assist in the removal of impurities; and self-sharpening properties, continuously exposing new active crystal edges during the polishing process to maintain a continuous and stable polishing capability. Furthermore, its service life is 3-5 times that of traditional abrasives such as iron oxide powder, combining environmental friendliness and economy.

[0004] With the increasing demands for workpiece surface precision in high-end manufacturing, single abrasive polishing slurries are no longer sufficient to meet complex processing requirements. The development of composite polishing slurries that combine excellent dispersion stability, interfacial adhesion, and polishing performance through organic matrix and inorganic abrasive modification has become a mainstream trend in the industry. Epoxy resin, due to its good adhesion, film-forming properties, and mechanical strength, is often used as the organic matrix for composite polishing slurries. It can synergistically interact with abrasive particles to improve the overall stability of the polishing slurry and the wear resistance of the polishing film. However, traditional epoxy-cerium oxide composite systems still suffer from insufficient interfacial adhesion and abrasive agglomeration, limiting further optimization of polishing performance.

[0005] The research and development of nano-cerium oxide polishing fluids has made some progress. For example, Chinese invention patent CN201910432776.3 discloses a nano-cerium oxide polishing fluid and its preparation method. The nano-cerium oxide polishing fluid comprises the following components in the following proportions: 5-30 parts nano-cerium oxide, 10-40 parts deionized water, 20-70 parts glycerol, and 1-5 parts compounded surfactant. This invention is used for polishing glass, which can improve polishing efficiency and effect without causing contamination to the glass or processing equipment. However, this polishing slurry still has significant technical shortcomings: the system does not introduce organic matrix components, and only uses glycerol as a solvent and wetting agent, and compound surfactants as a dispersion medium. The nano-cerium oxide is dispersed in the system only by the physical adsorption of surfactants, and there are no strong chemical bonds between it and the substrate. The interfacial bonding is weak, and abrasive particles are prone to fall off during the polishing process, which not only reduces the polishing efficiency, but may also leave particles on the glass surface or cause fine scratches, affecting the polishing precision. It relies only on the steric hindrance and electrostatic repulsion of surfactants and lacks long-term stable modification methods. In addition, the nano-cerium oxide itself has a high surface energy, and it is easy for particles to agglomerate during long-term storage or under temperature fluctuations, which leads to the deterioration of the polishing slurry performance and shortens its storage and service life.

[0006] In summary, existing nano-cerium oxide-based polishing slurries still have room for improvement in terms of interfacial bonding, dispersion stability, and polishing durability, and cannot fully meet the stringent requirements of ultra-precision polishing in high-end manufacturing. Therefore, developing a composite polishing slurry that enhances interfacial interaction and improves dispersion stability and polishing performance through matrix modification has become an important research direction in the field of polishing slurry technology. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, this invention improves epoxy resin and combines it with components such as nano-cerium oxide to prepare a composite polishing liquid with excellent interfacial bonding force, dispersion stability, polishing performance and storage durability.

[0008] To achieve the above objectives, the following technical solution is adopted: On the one hand, the present invention provides an epoxy resin-nano cerium oxide composite polishing liquid, comprising the following components in parts by weight: 10-25 parts of aqueous epoxy resin, 3-5 parts of modified epoxy resin, 15-30 parts of nano cerium oxide, 20-40 parts of water, 10-20 parts of ethanol, 2-5 parts of dispersant, 1-3 parts of surfactant, 0.5-2 parts of stabilizer, 0.1-0.5 parts of polydimethylsiloxane, and 0.3-1 parts of preservative.

[0009] Furthermore, the modified epoxy resin is prepared by the following steps: (1) Bisphenol A and epichlorohydrin were added to toluene as monomers, the temperature was raised to 80-90℃, sodium hydroxide was added as catalyst, and the temperature was raised to 90-100℃ after the addition was completed. The reaction was kept at a constant temperature for 2-4 hours. After the reaction was completed, deionized water was added to the system, the mixture was stirred for 30 minutes and then allowed to stand to separate into layers. The aqueous phase was removed, and the pH of the organic phase was adjusted to neutral with 5-10% dilute hydrochloric acid. The organic phase was then washed with deionized water and then distilled under reduced pressure to obtain epoxy resin. (2) Add epoxy resin to anhydrous ethanol, stir and heat to 60-70℃ to completely dissolve epoxy resin, slowly add γ-aminoethylaminopropyltrimethoxysilane dropwise, control the dropwise addition time to 30-40 min, after the dropwise addition is completed, heat to 70-80℃, keep the temperature constant for 1-2 h, and keep the stirring speed at 120-150 r / min; after the reaction is completed, cool the system to 40-50℃, and obtain silanized epoxy resin by vacuum distillation; (3) Add the silanized epoxy resin to N,N-dimethylformamide, stir and heat to 80-90℃, add tris(4-carboxyphenyl)imidazolium, fulvic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in sequence, stir evenly and heat to 100-120℃, and react at a constant temperature for 3-5h. After the reaction is completed, cool the system to room temperature and slowly pour it into anhydrous ethanol equivalent to 3 times the volume of the reaction system, stir to precipitate; after standing for 1-2h, filter to collect the precipitate, wash with anhydrous ethanol, vacuum dry to obtain modified epoxy resin, grind through a 100-mesh sieve for later use.

[0010] Further, in step (1), the molar ratio of bisphenol A to epichlorohydrin is 1:2-3; the amount of sodium hydroxide catalyst is 50-80% of the mass of bisphenol A; and the amount of toluene solvent is 1.5-2 times the total mass of bisphenol A and epichlorohydrin.

[0011] Further, in step (2), the mass ratio of epoxy resin to γ-aminoethylaminopropyltrimethoxysilane is 100:5-15; the amount of anhydrous ethanol solvent is 1-1.5 times the mass of epoxy resin; and the amount of glacial acetic acid catalyst is 0.1-0.3% of the mass of epoxy resin.

[0012] Further, in step (3), the mass ratio of silanized epoxy resin, tris(4-carboxyphenyl)imidazolium, and fulvic acid is 100:3-8:1-4; the amount of N,N-dimethylformamide solvent is 2-3 times the mass of silanized epoxy resin; and the amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride catalyst is 10-15% of the mass of tris(4-carboxyphenyl)imidazolium.

[0013] Furthermore, the particle size of the nano-cerium oxide is 50-200 nm.

[0014] Furthermore, the dispersant is selected from one or more of sodium polycarboxylate, sodium hexametaphosphate, and ammonium polyacrylate.

[0015] Furthermore, the surfactant is a nonionic surfactant selected from one or more of Tween 80, Span 80, and polyethylene glycol octylphenyl ether.

[0016] Furthermore, the stabilizer is selected from disodium EDTA and trisodium citrate.

[0017] Furthermore, the preservative is selected from sodium benzoate and potassium sorbate.

[0018] On the other hand, the present invention also provides a method for preparing an epoxy resin-nano cerium oxide composite polishing slurry, comprising the following steps: P1. Weigh the amount of water and ethanol in the formula, add them to the mixing tank, turn on the stirring, and the speed is 200-300 r / min. Add the modified epoxy resin and nano cerium oxide, heat to 40-50℃, stir for 30-40 min, and then ultrasonically disperse for 30-60 min at a power of 300-400W and a temperature of 50-60℃ to obtain the nano cerium oxide modified liquid. P2. Add water-based epoxy resin and other components to the nano-cerium oxide modified solution, increase the stirring speed to 500-600 r / min, stir for 1-2 h, then transfer the system to a sand mill and grind for 2-4 h, controlling the particle size D90 of the ground system to ≤300 nm, cool the ground system to room temperature, adjust the pH to 6.5-7.5, stir for 10-15 min, and after sieving, obtain the composite polishing solution.

[0019] The beneficial effects of this invention are: This invention innovatively introduces silane coupling agents, tris(4-carboxyphenyl)imidazole, and fulvic acid into the molecular structure of epoxy resin. These are then used as an organic matrix and modified with nano-cerium oxide. Finally, they are combined with water-soluble epoxy resin and other components to form a polishing fluid. The water-soluble epoxy resin component forms a flexible buffer film at the polishing interface, reducing the potential impact and scratch risk of rigid abrasives on the surface of precision workpieces, thus improving the safety and surface quality of the polishing process. The water-soluble epoxy resin significantly increases the overall viscosity of the polishing fluid and, through interaction with the epoxy resin on the surface of nano-cerium oxide, inhibits the aggregation tendency of nano-cerium oxide, ensuring excellent dispersion stability of the polishing fluid during storage and use.

[0020] This invention relates to a silane coupling agent that reacts with epoxy resin. Through the synergistic effect of amino and organosilicon groups in the molecule, the interfacial bonding force and overall stability of the system are significantly improved. The amino group can act as a nucleophile to attack the epoxy groups of the epoxy resin, causing them to open the ring and generate a large number of secondary hydroxyl groups, providing sufficient active sites for subsequent crosslinking reactions. At the same time, the amino group can form hydrogen bonds or ionic bonds with the modifier, strengthening the three-dimensional crosslinking network and enhancing the coordination activity of the modifier and the chemical polishing activity of cerium oxide. The silanol groups generated by the hydrolysis of the organosilicon groups condense with the hydroxyl groups on the surface of nano-cerium oxide to form stable covalent bonds, firmly anchoring cerium oxide in the epoxy resin matrix, solving the problem of easy detachment of cerium oxide particles in traditional systems. In addition, the organosilicon segments can relieve the internal stress of the matrix during curing, improve the wear resistance and weather resistance of the polishing film, reduce the surface tension of the epoxy resin, improve the wettability of the polishing liquid on the substrate surface, and ensure a uniform polishing rate.

[0021] Tris(4-carboxyphenyl)imidazolium has a structure consisting of a carboxyl group and an imidazole ring. The carboxyl group can undergo esterification with the hydroxyl groups generated during ring-opening of epoxy resin, thereby increasing the density of the cross-linked network and improving the hardness of the polished film. The carboxyl group can also react with Ce on the surface of cerium oxide. 3+ / Ce 4+ The formation of multidentate chelate coordination bonds further strengthens the interfacial bonding force, preventing particle shedding during polishing and improving polishing efficiency. The nitrogen atom of the imidazole ring can form secondary coordination bonds with cerium oxide, and simultaneously form hydrogen bonds with the amino group of the silane coupling agent. The triphenyl group forms a tripod structure, which can exert a significant steric hindrance effect, inhibiting cerium oxide agglomeration and extending the shelf life of the polishing solution. Fulvic acid contains active oxygen functional groups, which form a synergistic modification effect with tris(4-carboxyphenyl)imidazole, further optimizing the performance of the polishing solution. Its carboxyl and hydroxyl groups can form esterification or hydrogen bonding with epoxy resin, supplementing crosslinking sites, and simultaneously forming coordination bonds with cerium oxide, synergistically enhancing the interfacial bonding force. The anionic properties give the cerium oxide surface a uniform negative charge, achieving dual dispersion through electrostatic repulsion. Combined with the steric hindrance effect of tris(4-carboxyphenyl)imidazole, it reduces the surface roughness of the substrate after polishing. The phenolic hydroxyl groups can stabilize the Ce on the cerium oxide surface. 3+ Active sites inhibit oxidation, maintain chemical polishing activity, and reduce surface damage; flexible segments can alleviate substrate curing stress and improve the toughness and service life of the polished film. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the preparation process of the composite polishing liquid in various embodiments of the present invention; Figure 2 The graph shows the zeta potential measurement results of the polishing slurries prepared in the various embodiments and comparative examples of the present invention in the dispersion stability test. Figure 3 The graph shows the particle size distribution (D90 value) measurement results in the dispersion stability test of the polishing slurries prepared in various embodiments and comparative examples of the present invention; Figure 4 The graph shows the results of material removal rate per unit time in the polishing performance test of the polishing slurries prepared in various embodiments and comparative examples of the present invention. Figure 5 The graph shows the average roughness (Ra) measurement results of the polishing slurries prepared in various embodiments and comparative examples of the present invention in the polishing performance test; Figure 6 The graph shows the results of D90 growth rate determination of the polishing fluids prepared in the various embodiments and comparative examples of the present invention after 30 days of storage stability testing.

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0026] It should be noted that the composite polishing slurry prepared in this application can be applied to the grinding and polishing of semiconductor materials such as wafers and chips, and can also be applied to the grinding and polishing of products such as optical fiber materials, automotive parts, and optical components. The specific application scenarios are not specifically limited.

[0027] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all commercially available. The bisphenol A used in all embodiments of the present invention is ordinary bisphenol A type epoxy resin (model E-44, epoxy value 0.44). The preparation process of the composite polishing liquid in each embodiment of the present invention is shown in the attached figure. Figure 1 As shown.

[0028] Example 1: An epoxy resin-nano cerium oxide composite polishing fluid The composite polishing liquid comprises the following components in parts by weight: 10 parts of waterborne epoxy resin, 3 parts of modified epoxy resin, 15 parts of nano-cerium oxide, 20 parts of water, 10 parts of ethanol, 2 parts of dispersant, 1 part of surfactant, 0.5 parts of stabilizer, 0.1 parts of polydimethylsiloxane, and 0.3 parts of preservative.

[0029] The modified epoxy resin is prepared by the following steps: (1) Bisphenol A and epichlorohydrin were added to toluene as monomers, the temperature was raised to 80°C, sodium hydroxide was added as a catalyst, the temperature was raised to 90°C after the addition was completed, and the reaction was kept at a constant temperature for 2 hours. After the reaction was completed, deionized water was added to the system, the mixture was stirred for 30 minutes and then allowed to stand to separate into layers. The aqueous phase was removed, and the pH of the organic phase was adjusted to neutral with 5% hydrochloric acid. The organic phase was then washed with deionized water and then distilled under reduced pressure to obtain epoxy resin. (2) Add epoxy resin to anhydrous ethanol, stir and heat to 60°C to completely dissolve epoxy resin, slowly add γ-aminoethylaminopropyltrimethoxysilane dropwise, control the dropwise addition time to 30 min, after the dropwise addition is completed, heat to 70°C, keep the temperature constant for 1 h, and keep the stirring speed at 120 r / min; after the reaction is completed, cool the system to 40°C, and obtain silanized epoxy resin by vacuum distillation. (3) Add the silanized epoxy resin to N,N-dimethylformamide, stir and heat to 80°C, add tris(4-carboxyphenyl)imidazolium, fulvic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in sequence, stir evenly and heat to 100°C, and react at a constant temperature for 3 hours. After the reaction is completed, cool the system to room temperature and slowly pour it into anhydrous ethanol equivalent to 3 times the volume of the reaction system. Stir to precipitate the precipitate. After standing for 1 hour, filter and collect the precipitate, wash with anhydrous ethanol, and vacuum dry to obtain modified epoxy resin. Grind and pass through a 100-mesh sieve for later use.

[0030] In step (1), the molar ratio of bisphenol A to epichlorohydrin is 1:2; the amount of sodium hydroxide catalyst is 50% of the mass of bisphenol A; and the amount of toluene solvent is 1.5 times the total mass of bisphenol A and epichlorohydrin.

[0031] In step (2), the mass ratio of epoxy resin to γ-aminoethylaminopropyltrimethoxysilane is 100:5; the amount of anhydrous ethanol solvent is 1 times the mass of epoxy resin; and the amount of glacial acetic acid catalyst is 0.1% of the mass of epoxy resin.

[0032] In step (3), the mass ratio of silanized epoxy resin, tris(4-carboxyphenyl)imidazolium, and fulvic acid is 100:3:1; the amount of N,N-dimethylformamide solvent is twice the mass of silanized epoxy resin; and the amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride catalyst is 10% of the mass of tris(4-carboxyphenyl)imidazolium.

[0033] The nano-cerium oxide has a particle size of 50 nm; the dispersant is sodium polycarboxylate; the surfactant is Tween 80; the stabilizer is disodium EDTA; and the preservative is sodium benzoate.

[0034] A method for preparing an epoxy resin-nano cerium oxide composite polishing slurry includes the following steps: P1. Weigh the amount of water and ethanol in the formula, add them to the mixing tank, turn on the stirring, and the speed is 200 r / min. Add the modified epoxy resin and nano cerium oxide, heat to 40℃, stir for 30 min, and then ultrasonically disperse for 30 min at a power of 300W and a temperature of 50℃ to obtain the nano cerium oxide modified liquid. P2. Add waterborne epoxy resin and other components to the nano-cerium oxide modified solution, increase the stirring speed to 500 r / min, stir for 1 h, then transfer the system to a sand mill and grind for 2 h. Control the particle size D90 of the ground system to ≤300 nm, cool the ground system to room temperature, adjust the pH to 6.5, stir for 10 min, and after sieving, obtain the composite polishing solution.

[0035] Example 2: An epoxy resin-nano cerium oxide composite polishing liquid The composite polishing liquid comprises the following components in parts by weight: 25 parts of waterborne epoxy resin, 5 parts of modified epoxy resin, 30 parts of nano-cerium oxide, 40 parts of water, 20 parts of ethanol, 5 parts of dispersant, 3 parts of surfactant, 2 parts of stabilizer, 0.5 parts of polydimethylsiloxane, and 1 part of preservative.

[0036] The modified epoxy resin is prepared by the following steps: (1) Bisphenol A and epichlorohydrin were added to toluene as monomers, the temperature was raised to 90°C, sodium hydroxide was added as a catalyst, the temperature was raised to 100°C after the addition was completed, and the reaction was kept at a constant temperature for 4 hours. After the reaction was completed, deionized water was added to the system, the mixture was stirred for 30 minutes and then allowed to stand to separate into layers. The aqueous phase was removed, the pH of the organic phase was adjusted to neutral with 10% hydrochloric acid, and then washed with deionized water. The epoxy resin was then obtained by vacuum distillation. (2) Add epoxy resin to anhydrous ethanol, stir and heat to 70°C to completely dissolve epoxy resin, slowly add γ-aminoethylaminopropyltrimethoxysilane dropwise, control the dropwise addition time to 40 min, after the dropwise addition is completed, heat to 80°C, keep the temperature constant for 2 h, and keep the stirring speed at 150 r / min; after the reaction is completed, cool the system to 50°C, and obtain silanized epoxy resin by vacuum distillation. (3) Add the silanized epoxy resin to N,N-dimethylformamide, stir and heat to 90°C, add tris(4-carboxyphenyl)imidazolium, fulvic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in sequence, stir evenly and heat to 120°C, and react at a constant temperature for 5 hours. After the reaction is completed, cool the system to room temperature and slowly pour it into anhydrous ethanol equivalent to 3 times the volume of the reaction system. Stir to precipitate the precipitate. After standing for 2 hours, filter and collect the precipitate, wash with anhydrous ethanol, and vacuum dry to obtain modified epoxy resin. Grind it through a 100-mesh sieve for later use.

[0037] In step (1), the molar ratio of bisphenol A to epichlorohydrin is 1:3; the amount of sodium hydroxide catalyst is 80% of the mass of bisphenol A; and the amount of toluene solvent is twice the total mass of bisphenol A and epichlorohydrin.

[0038] In step (2), the mass ratio of epoxy resin to γ-aminoethylaminopropyltrimethoxysilane is 100:15; the amount of anhydrous ethanol solvent is 1.5 times the mass of epoxy resin; and the amount of glacial acetic acid catalyst is 0.3% of the mass of epoxy resin.

[0039] In step (3), the mass ratio of silanized epoxy resin, tris(4-carboxyphenyl)imidazolium, and fulvic acid is 100:8:4; the amount of N,N-dimethylformamide solvent is 3 times the mass of silanized epoxy resin; and the amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride catalyst is 15% of the mass of tris(4-carboxyphenyl)imidazolium.

[0040] The nano-cerium oxide has a particle size of 200 nm; the dispersant is sodium hexametaphosphate; the surfactant is Span 80; the stabilizer is trisodium citrate; and the preservative is potassium sorbate.

[0041] A method for preparing an epoxy resin-nano cerium oxide composite polishing slurry includes the following steps: P1. Weigh the amount of water and ethanol in the formula, add them to the mixing tank, turn on the stirring, and the speed is 300 r / min. Add the modified epoxy resin and nano cerium oxide, heat to 50℃, stir for 40 min, and then ultrasonically disperse for 60 min at a power of 400W and a temperature of 60℃ to obtain the nano cerium oxide modified liquid. P2. Add water-based epoxy resin and other components to the nano-cerium oxide modified liquid, increase the stirring speed to 600 r / min, stir for 2 h, then transfer the system to a sand mill and grind for 4 h. Control the particle size D90 of the ground system to ≤300 nm, cool the ground system to room temperature, adjust the pH to 7.5, stir for 15 min, and after sieving, obtain the composite polishing liquid.

[0042] Example 3: An epoxy resin-nano cerium oxide composite polishing liquid The composite polishing liquid comprises the following components in parts by weight: 18 parts of waterborne epoxy resin, 4 parts of modified epoxy resin, 23 parts of nano-cerium oxide, 30 parts of water, 15 parts of ethanol, 3 parts of dispersant, 2 parts of surfactant, 1 part of stabilizer, 0.3 parts of polydimethylsiloxane, and 0.6 parts of preservative.

[0043] The modified epoxy resin is prepared by the following steps: (1) Bisphenol A and epichlorohydrin were added to toluene as monomers, the temperature was raised to 85°C, sodium hydroxide was added as a catalyst, the temperature was raised to 95°C after the addition was completed, and the reaction was kept at a constant temperature for 3 hours. After the reaction was completed, deionized water was added to the system, the mixture was stirred for 30 minutes and then allowed to stand to separate into layers. The aqueous phase was removed, and the pH of the organic phase was adjusted to neutral with 7.5% dilute hydrochloric acid. The organic phase was then washed with deionized water and then distilled under reduced pressure to obtain epoxy resin. (2) Add epoxy resin to anhydrous ethanol, stir and heat to 65°C to completely dissolve epoxy resin, slowly add γ-aminoethylaminopropyltrimethoxysilane dropwise, control the dropwise addition time to 35 min, after the dropwise addition is completed, heat to 75°C, keep the temperature constant for 1.5 h, and keep the stirring speed at 135 r / min; after the reaction is completed, cool the system to 45°C, and obtain silanized epoxy resin by vacuum distillation. (3) Add the silanized epoxy resin to N,N-dimethylformamide, stir and heat to 85°C, add tris(4-carboxyphenyl)imidazolium, fulvic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in sequence, stir evenly and heat to 110°C, and react at a constant temperature for 4 hours. After the reaction is completed, cool the system to room temperature and slowly pour it into anhydrous ethanol equivalent to 3 times the volume of the reaction system. Stir to precipitate the precipitate. After standing for 1.5 hours, filter and collect the precipitate, wash with anhydrous ethanol, and vacuum dry to obtain modified epoxy resin. Grind and pass through a 100-mesh sieve for later use.

[0044] In step (1), the molar ratio of bisphenol A to epichlorohydrin is 1:2.5; the amount of sodium hydroxide catalyst is 65% of the mass of bisphenol A; and the amount of toluene solvent is 1.75 times the total mass of bisphenol A and epichlorohydrin.

[0045] In step (2), the mass ratio of epoxy resin to γ-aminoethylaminopropyltrimethoxysilane is 100:10; the amount of anhydrous ethanol solvent is 1.25 times the mass of epoxy resin; and the amount of glacial acetic acid catalyst is 0.2% of the mass of epoxy resin.

[0046] In step (3), the mass ratio of silanized epoxy resin, tris(4-carboxyphenyl)imidazolium, and fulvic acid is 100:5:2; the amount of N,N-dimethylformamide solvent is 2.5 times the mass of silanized epoxy resin; and the amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride catalyst is 12.5% ​​of the mass of tris(4-carboxyphenyl)imidazolium.

[0047] The nano-cerium oxide has a particle size of 125 nm; the dispersant is ammonium polyacrylate and sodium polycarboxylate in a mass ratio of 1:1; the surfactant is polyethylene glycol octylphenyl ether and Tween 80 in a mass ratio of 1:1; the stabilizer is trisodium citrate; and the preservative is sodium benzoate.

[0048] A method for preparing an epoxy resin-nano cerium oxide composite polishing slurry includes the following steps: P1. Weigh the amount of water and ethanol in the formula, add them to the mixing tank, turn on the stirring, and the speed is 250 r / min. Add the modified epoxy resin and nano cerium oxide, heat to 45℃, stir for 35 min, and then ultrasonically disperse for 40 min at a power of 350W and a temperature of 55℃ to obtain the nano cerium oxide modified liquid. P2. Add water-based epoxy resin and other components to the nano-cerium oxide modified solution, increase the stirring speed to 550 r / min, stir for 1.5 h, then transfer the system to a sand mill and grind for 3 h. Control the particle size D90 of the system after grinding to ≤300 nm, cool the system after grinding to room temperature, adjust the pH to 7.0, stir for 12 min, and after sieving, obtain the composite polishing solution.

[0049] Comparative Example 1: The difference between this comparative example and Example 3 is that ordinary bisphenol A type epoxy resin (model E-44, epoxy value 0.44) without any modification is used instead of the modified epoxy resin described in this invention.

[0050] Comparative Example 2: The difference between this comparative example and Example 3 is that the silanized epoxy resin prepared only by steps (1) and (2) was used without further modification in step (3), i.e. it does not contain tris(4-carboxyphenyl)imidazolium and fulvic acid.

[0051] Comparative Example 3: The difference between this comparative example and Example 3 is that no epoxy resin components (including modified or unmodified epoxy resins and waterborne epoxy resins) are added, and the amount of dispersant is increased in an attempt to maintain the dispersibility of the system.

[0052] The composite polishing solution of this comparative example comprises the following components in parts by weight: 23 parts nano-cerium oxide, 30 parts water, 15 parts ethanol, 6 parts dispersant (ammonium polyacrylate and sodium polycarboxylate, mass ratio 1:1, total amount twice that of Example 3), 2 parts surfactant (polyethylene glycol octylphenyl ether and Tween 80, mass ratio 1:1), 1 part stabilizer (trisodium citrate), 0.3 parts polydimethylsiloxane, and 0.6 parts preservative (sodium benzoate).

[0053] Results Analysis Test Example 1: Dispersion Stability Test Referring to GB / T 32671.1-2016 "Method for Measurement of Zeta Potential of Colloidal Systems" and GB / T 19077-2016 "Laser Diffraction Method for Particle Size Analysis", the Zeta potential and particle size distribution (D90) were tested using a Malvern Zetasizer Nano ZS laser particle size and Zeta potential analyzer. The specific steps are as follows: After ultrasonically dispersing each polishing liquid sample for 5 min, an appropriate amount was placed in the sample cell and the Zeta potential and particle size distribution (D90 value) were measured at a constant temperature of 25℃. Each sample was tested in parallel three times and the average value was taken to evaluate the electrostatic stability and particle aggregation of the system.

[0054] Test results are as follows Figure 2 and Figure 3 As shown, the three embodiments of the present invention all exhibit high absolute values ​​of Zeta potential, with initial D90 particle sizes controlled below 300 nm, and minimal particle size growth after storage, indicating that the system possesses excellent electrostatic repulsion and steric hindrance effects, resulting in good dispersion stability. In contrast, the comparative samples showed significantly worse performance across all indicators, especially the unmodified comparative example 1 and the comparative example 3 lacking a resin matrix, exhibiting severe agglomeration and sedimentation.

[0055] Test Example 2: Polishing Performance Test Referring to the polishing performance testing methods commonly used in the semiconductor industry, the material removal rate (MRR) and surface roughness (Ra) after polishing were tested using a UNIPOL-1502 precision polishing machine and a surface profilometer. The specific steps are as follows: 4-inch silicon wafers (100 crystal faces) of the same specifications were used as the polishing object. Polishing was performed under the same conditions: polishing pressure (3 psi), polishing disc speed (60 rpm), polishing slurry supply rate (150 mL / min), and polishing time (10 min). The mass of the silicon wafers was weighed using a precision electronic balance before and after polishing, and the material removal rate (MRR) per unit time was calculated. After polishing, the arithmetic mean roughness (Ra) was measured at five randomly selected locations on the silicon wafer surface using a surface profilometer, and the average value was taken as the final roughness result.

[0056] Test results are as follows Figure 4 and Figure 5 As shown, the material removal rate (MRR) of the embodiments of the present invention is higher than that of all comparative examples, while the surface roughness (Ra) after polishing is lower, achieving a balance between high efficiency and high precision. This confirms that the strong interfacial bonding force provided by the modified epoxy resin can effectively transfer polishing force and fix the abrasive, avoiding ineffective detachment and scratches.

[0057] Test Example 3: Storage Stability Test Referring to industry-standard accelerated storage testing methods, particle size analysis was used to evaluate the long-term storage stability of the polishing slurry. The specific steps are as follows: Each polishing slurry sample was placed in a 50ml graduated transparent glass bottle, sealed, and placed in a 50℃ constant temperature oven for accelerated storage experiments. The D90 particle size was measured before storage and 30 days after storage, according to the method in Test Example 1, and the particle size growth rate was calculated to evaluate anti-agglomeration and long-term dispersion stability.

[0058] Test case results are as follows Figure 6 As shown, after 30 days of accelerated storage at 50°C, all embodiments of the present invention exhibited good stability and minimal particle size change.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0060] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An epoxy resin-nano cerium oxide composite polishing slurry, characterized in that: It comprises the following components in parts by weight: 10-25 parts waterborne epoxy resin, 3-5 parts modified epoxy resin, 15-30 parts nano-cerium oxide, 20-40 parts water, 10-20 parts ethanol, 2-5 parts dispersant, 1-3 parts surfactant, 0.5-2 parts stabilizer, 0.1-0.5 parts polydimethylsiloxane, and 0.3-1 parts preservative; The modified epoxy resin is prepared by the following steps: (1) Bisphenol A and epichlorohydrin were added to toluene as monomers, the temperature was raised to 80-90℃, sodium hydroxide was added as catalyst, and the temperature was raised to 90-100℃ after the addition was completed. The reaction was kept at a constant temperature for 2-4 hours. After the reaction was completed, deionized water was added to the system, the mixture was stirred for 30 minutes and then allowed to stand to separate into layers. The aqueous phase was removed, and the pH of the organic phase was adjusted to neutral with 5-10% dilute hydrochloric acid. The organic phase was then washed with deionized water and then distilled under reduced pressure to obtain epoxy resin. (2) Add epoxy resin to anhydrous ethanol, stir and heat to 60-70℃ to completely dissolve epoxy resin, slowly add γ-aminoethylaminopropyltrimethoxysilane dropwise, control the dropwise addition time to 30-40 min, after the dropwise addition is completed, heat to 70-80℃, keep the temperature constant for 1-2 h, and keep the stirring speed at 120-150 r / min; after the reaction is completed, cool the system to 40-50℃, and obtain silanized epoxy resin by vacuum distillation; (3) Add the silanized epoxy resin to N,N-dimethylformamide, stir and heat to 80-90℃, add tris(4-carboxyphenyl)imidazolium, fulvic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in sequence, stir evenly and heat to 100-120℃, and react at a constant temperature for 3-5h. After the reaction is completed, cool the system to room temperature and slowly pour it into anhydrous ethanol equivalent to 3 times the volume of the reaction system, stir to precipitate; after standing for 1-2h, filter to collect the precipitate, wash with anhydrous ethanol, vacuum dry to obtain modified epoxy resin, grind through a 100-mesh sieve for later use.

2. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 1, characterized in that: In step (1), the molar ratio of bisphenol A to epichlorohydrin is 1:2-3; the amount of sodium hydroxide catalyst is 50-80% of the mass of bisphenol A; and the amount of toluene solvent is 1.5-2 times the total mass of bisphenol A and epichlorohydrin.

3. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 2, characterized in that: In step (2), the mass ratio of epoxy resin to γ-aminoethylaminopropyltrimethoxysilane is 100:5-15; the amount of anhydrous ethanol solvent is 1-1.5 times the mass of epoxy resin; and the amount of glacial acetic acid catalyst is 0.1-0.3% of the mass of epoxy resin.

4. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 3, characterized in that: In step (3), the mass ratio of silanized epoxy resin, tris(4-carboxyphenyl)imidazolium, and fulvic acid is 100:3-8:1-4; the amount of N,N-dimethylformamide solvent is 2-3 times the mass of silanized epoxy resin; and the amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride catalyst is 10-15% of the mass of tris(4-carboxyphenyl)imidazolium.

5. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 4, characterized in that: The particle size of the nano-cerium oxide is 50-200 nm.

6. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 5, characterized in that: The dispersant is selected from one or more of sodium polycarboxylate, sodium hexametaphosphate, and ammonium polyacrylate.

7. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 6, characterized in that: The surfactant is a nonionic surfactant selected from one or more of Tween 80, Span 80, and polyethylene glycol octylphenyl ether.

8. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 7, characterized in that: The stabilizer is selected from disodium EDTA and trisodium citrate.

9. The epoxy resin-nano cerium oxide composite polishing slurry according to claim 8, characterized in that: The preservative is selected from sodium benzoate and potassium sorbate.

10. A method for preparing the epoxy resin-nano cerium oxide composite polishing liquid according to any one of claims 1-9, characterized in that: Includes the following steps: P1. Weigh the amount of water and ethanol in the formula, add them to the mixing tank, turn on the stirring, and the speed is 200-300 r / min. Add the modified epoxy resin and nano cerium oxide, heat to 40-50℃, stir for 30-40 min, and then ultrasonically disperse for 30-60 min at a power of 300-400W and a temperature of 50-60℃ to obtain the nano cerium oxide modified liquid. P2. Add water-based epoxy resin and other components to the nano-cerium oxide modified solution, increase the stirring speed to 500-600 r / min, stir for 1-2 h, then transfer the system to a sand mill and grind for 2-4 h, controlling the particle size D90 of the ground system to ≤300 nm, cool the ground system to room temperature, adjust the pH to 6.5-7.5, stir for 10-15 min, and after sieving, obtain the composite polishing solution.

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