Environment-friendly high-lubrication water-based cutting fluid for semiconductor cutting and preparation method of environment-friendly high-lubrication water-based cutting fluid

Abstract

The invention provides an environment-friendly high-lubrication water-based cutting fluid for semiconductor cutting. The invention relates to a water-based adhesive, which is prepared from the following ingredients in parts by weight: 0.5 to 1.5 parts of alkyl glycoside surface modified cross-linked starch nanometer microspheres, 5.0 to 8.0 parts of polyglycerol, 3.0 to 5.0 parts of food-grade white mineral oil, 1.0 to 2.0 parts of tannic acid, 1.0 to 2.0 parts of sodium gluconate, 0.5 to 1.0 part of carbonic acid cyclohexylamine, 2.0 to 4.0 parts of alkyl glycoside, 1.0 to 2.0 parts of fatty alcohol-polyoxyethylene ether, 0.1 to 0.3 part of organic silicon defoaming agents, 0.1 to 0.2 part of isothiazolinone derivatives, 0.5 to 1.5 parts of 2-amino-2-methyl-1-propyl alcohol and 65.0 to 85.0 parts of deionized water. According to the invention, the biodegradable surface modified starch nano-microspheres, polyglycerol and white oil are adopted to construct'triple-mode 'lubrication, and tannic acid, sodium gluconate and cyclohexylamine carbonate are utilized to form a synergistic antirust system, so that the risk that a wafer is scratched by hard particles is completely eradicated. The cutting fluid does not contain harmful substances such as sulfur, chlorine and boron, has the characteristics of high lubrication, rust prevention, easy cleaning and environmental protection, and is suitable for precise cutting of semiconductors.

Description

Technical Field

[0001] This invention belongs to the field of metalworking fluid technology, specifically relating to a water-based cutting fluid that can be used for device processing in semiconductor manufacturing processes. Background Technology

[0002] Water-based cutting fluids are crucial auxiliary materials in semiconductor wafer cutting, grinding, and other processing steps, and their performance directly affects tool life, machining accuracy, workpiece surface quality, and production costs. An ideal semiconductor cutting fluid must simultaneously meet stringent requirements such as high lubricity, excellent rust prevention, superb cleaning properties, absolute chemical compatibility, and environmental and operator friendliness.

[0003] In recent years, the industry has conducted numerous explorations to improve the lubrication performance of cutting fluids, but existing technical solutions still have a series of technical defects that urgently need to be addressed, mainly in the following aspects: Firstly, in lubrication technology, many solutions introduce high-hardness nanoparticles to achieve super-lubricating effects. For example, existing technologies (such as CN115948193B) use hard inorganic particles with a Mohs hardness of 8 or higher, such as zirconium oxide and tungsten carbide, to reduce friction through their "micro-bearing" effect. However, these hard particles are prone to embedding in or scratching the soft wafer surface during precision machining, leading to micro-damage to the circuitry, and pose a risk of residual contamination due to their difficulty in thorough cleaning. Other technologies (such as CN116751617B and CN115960671B) rely on complex nanocomposite materials (such as porous graphene oxide loaded with sulfurized fatty acid esters and boron nitride-loaded nanospheres). While these materials are ingeniously designed, their synthesis processes are cumbersome and lengthy, involving multiple steps of high-temperature, high-pressure, or vacuum reactions, resulting in high production costs, difficulty in batch stability control, and challenges in large-scale industrial applications.

[0004] Secondly, existing technologies have significant shortcomings in terms of environmental friendliness and chemical safety. Some formulations (such as CN113563959B and CN115746945B) introduce compounds containing sulfur and chlorine to improve extreme pressure anti-wear or anti-rust properties. These elements are strictly controlled pollutants in the semiconductor industry and may migrate to the chip surface, causing corrosion of metal circuits and seriously affecting the long-term reliability and yield of devices. In addition, some plant oil-based technologies (such as CN109233946B), although initially biodegradable, are prone to oxidation and rancidity due to their unsaturated bonds, leading to a shortened cutting fluid life and the potential for microbial growth.

[0005] Furthermore, existing technologies face challenges in balancing rust prevention and cleaning performance. Many rust inhibitors are incompatible with other components in the system or are inherently toxic. On the other hand, the excessive use of surfactants to achieve a cleaning effect can easily lead to excessive foaming, affecting processing visibility and cooling efficiency, forcing the addition of defoamers to the formulation, increasing the complexity and potential instability of the system.

[0006] In summary, existing technologies have failed to provide a water-based cutting fluid solution that achieves a perfect balance between high-performance lubrication, absolute material safety, inherent environmental friendliness, low cost, and ease of processing, particularly a cutting fluid product that can fundamentally eliminate hard particle residue contamination while meeting semiconductor-grade cleanliness requirements. Therefore, there is an urgent need in the field for an innovative technical solution to overcome these systemic deficiencies and meet the extreme requirements of modern semiconductor manufacturing for cutting fluids. Summary of the Invention

[0007] This invention aims to solve the core technical challenge of balancing lubrication performance and environmental safety in existing water-based cutting fluids for semiconductor cutting applications, particularly addressing bottlenecks such as hard particle residue pollution, the presence of restricted harmful elements, complex and costly formulations, and poor biodegradability. By employing an innovative strategy of "triple-modal lubrication" and "molecular self-assembly rust prevention," a green lubrication system is creatively constructed using biodegradable, surface-modified starch nanospheres and polyglycerol-food-grade white oil to achieve synergistic lubrication of "rolling-fluid-boundary," fundamentally eliminating the risk of scratches from hard particles. A molecular self-assembly synergistic rust-preventive film is constructed using tannic acid-sodium gluconate-cyclohexylamine carbonate, achieving excellent environmentally friendly rust protection. Furthermore, an efficient cleaning system is built primarily with alkyl glycosides, ensuring both superior cleaning performance and biodegradability. Ultimately, a new water-based cutting fluid system is formed, possessing comprehensive advantages such as high-performance lubrication, excellent rust prevention, inherent environmental friendliness, low cost, and easy cleaning, making it particularly suitable for precision semiconductor wafer cutting applications with extremely high processing accuracy and cleanliness requirements.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: On one hand, the present invention provides a water-based cutting fluid with excellent lubrication and rust prevention properties, comprising a lubricant, a rust inhibitor, a surfactant, a defoamer, a bactericide, a pH stabilizer, deionized water, and surface-modified starch nanospheres as a key lubricating component, and is composed of the following components in parts by weight: 0.5–1.5 parts of cross-linked starch nanospheres modified with alkyl glycosides; Polyglycerol 5.0–8.0 parts; Food-grade white mineral oil, 3.0–5.0 parts; Tannic acid 1.0–2.0 parts; Sodium gluconate 1.0–2.0 parts; Cyclohexylamine carbonate 0.5–1.0 parts; Alkyl glycosides, 2.0–4.0 parts; 1.0 to 2.0 parts of fatty alcohol polyoxyethylene ether; 0.1 to 0.3 parts of silicone defoamer; 0.1–0.2 parts of isothiazolinone derivative; 0.5 to 1.5 parts of 2-amino-2-methyl-1-propanol; 65.0–85.0 parts of deionized water.

[0009] The surface-modified starch nanospheres have an alkyl glycoside surface modification degree of 30%-70%, a surface contact angle ≥90°, and an absolute value of Zeta potential ≥20mV, ensuring their dispersion stability in the system.

[0010] The method for preparing the surface-modified starch nanospheres includes the following steps: (1) Preparation of cross-linked starch nanospheres: 10-20 parts by weight of natural starch were dispersed in 80-100 parts by weight of deionized water and stirred and gelatinized at 40-50°C for 30 minutes; 1%-5% of the dry weight of starch was added as a cross-linking agent, citric acid or sodium trimetaphosphate, and dilute alkali solution was added dropwise to adjust the pH of the system to 9-11. The temperature was raised to 55-65°C and reacted at a constant temperature for 2-4 hours; after the reaction was completed, the mixture was cooled to room temperature, neutralized, centrifuged and washed, and then freeze-dried to obtain cross-linked starch nanosphere substrate; (2) Surface adsorption and hydrophobic modification: The above microsphere substrate is dispersed in deionized water at 60-70℃ at a mass concentration of 5% to 10%. An alkyl glycoside aqueous solution of 10% to 20% of the dry weight of the microspheres is slowly added dropwise under high-speed stirring, and the reaction is continued for 1 to 2 hours. (3) Drying and post-treatment: The reaction product is separated by centrifugation, vacuum dried at 50-60℃ to constant weight, and then pulverized by air jet and passed through a 400-600 mesh sieve to obtain surface-modified starch nanospheres.

[0011] The lubricant comprises polyglycerol and food-grade white mineral oil, wherein the polyglycerol accounts for 5.0 to 8.0% by mass in the water-based cutting fluid, and the food-grade white mineral oil accounts for 3.0 to 5.0% by mass in the water-based cutting fluid.

[0012] The rust inhibitor comprises tannic acid, sodium gluconate, and cyclohexylamine carbonate, wherein the mass percentage of tannic acid in the water-based cutting fluid is between 1.0% and 2.0%, the mass percentage of sodium gluconate in the water-based cutting fluid is between 1.0% and 2.0%, and the mass percentage of cyclohexylamine carbonate in the water-based cutting fluid is between 0.5% and 1.0%.

[0013] The surfactant comprises alkyl glycoside and fatty alcohol polyoxyethylene ether, wherein the alkyl glycoside has a mass percentage of 2.0% to 4.0% in the water-based cutting fluid, and the fatty alcohol polyoxyethylene ether has a mass percentage of 1.0% to 2.0% in the water-based cutting fluid.

[0014] The defoamer is an organosilicon defoamer, and its mass percentage in the water-based cutting fluid is between 0.1% and 0.3%.

[0015] The bactericide is an isothiazolinone derivative, and its mass percentage in the water-based cutting fluid is between 0.1% and 0.2%.

[0016] The pH stabilizer is 2-amino-2-methyl-1-propanol, and its dosage is 0.5 to 1.5 parts by weight, used to adjust the pH value of the water-based cutting fluid to between 7.5 and 8.0.

[0017] The deionized water constitutes 65.0% to 85.0% of the water-based cutting fluid by mass.

[0018] On the other hand, the present invention provides a method for preparing the above-mentioned water-based cutting fluid, comprising the following steps: (1) Preparation of surface-modified starch nanospheres Take a reaction vessel equipped with a stirrer and thermometer, add natural starch and deionized water, and stir and gelatinize at 40-50℃ for 30 minutes; add a crosslinking agent, adjust the pH to 9-11, and heat to 55-65℃ for 2-4 hours; after the reaction is completed, cool, neutralize, centrifuge, wash and freeze dry; redisperse the obtained microsphere substrate in deionized water at 60-70℃, add an alkyl glycoside aqueous solution, and stir for 1-2 hours; finally, centrifuge, vacuum dry, air jet mill and pass through a 400-600 mesh sieve to obtain surface-modified starch nanospheres.

[0019] (2) Preparation of water-based cutting fluid Tannic acid, sodium gluconate, polyglycerol, alkyl glycoside, and fatty alcohol polyoxyethylene ether were sequentially added to a portion of deionized water and stirred until completely dissolved. In another container, food-grade white mineral oil and cyclohexylamine carbonate were mixed evenly. The oil phase mixture was slowly added to the aqueous phase under high-speed stirring to form an emulsion. Surface-modified starch nanospheres were added and dispersed evenly before adding the remaining deionized water. The pH was adjusted to 7.5–8.0 with 2-amino-2-methyl-1-propanol. Finally, an organosilicon defoamer and an isothiazolinone derivative were added and stirred evenly to obtain the water-based cutting fluid. Beneficial effects

[0020] Compared with the prior art, the water-based cutting fluid of the present invention has the following advantages for semiconductor material cutting and processing: On the one hand, the surface-modified starch nanospheres in the water-based cutting fluid of this invention have a unique micro-rolling bearing effect. Together with the fluid lubrication of polyglycerol and the boundary lubrication of food-grade white mineral oil, they form a "triple-modal lubrication" system. This system can intelligently respond to changes in pressure and temperature during the cutting process, significantly reducing the coefficient of friction and cutting force. At the same time, because its hardness is much lower than that of silicon wafers, it can completely avoid the risk of hard particles scratching and embedding on the wafer surface.

[0021] On the other hand, the "molecular self-assembly" synergistic rust-preventive system composed of tannic acid, sodium gluconate, and cyclohexylamine carbonate can spontaneously form a dense and robust composite protective film on the metal surface, providing excellent inter-process rust prevention capabilities. At the same time, all components are environmentally friendly materials, completely free of elements such as sulfur, chlorine, and boron that are harmful to semiconductor processes, eliminating pollution risks at the source, and possessing excellent biodegradability and cleaning performance.

[0022] Furthermore, the cutting fluid prepared by this invention was tested for biodegradability over 90% after 28 days, meeting the rapid biodegradation standard. After accelerated stability testing (40℃, 30 days), the system showed no stratification or precipitation, and the rust prevention performance retention rate was ≥95%, indicating that it has excellent storage stability and service life. Attached Figure Description

[0023] Figure 1 This is a scanning electron microscope image of cross-linked starch nanospheres modified with alkyl glycosides, as shown in Example 1. Figure 2 Friction and wear curves of Example 2; Figure 3 Friction and wear curves of Example 3; Figure 4 Friction and wear curves of Example 4; Figure 5 Friction and wear curves for Comparative Example 1; Figure 6 Friction and wear curves for Comparative Example 2. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to specific embodiments. The scope of protection of the present invention is not limited to the following embodiments; these examples are provided for illustrative purposes only and do not limit the present invention in any way.

[0025] In the embodiments, "parts" refers to "parts by weight".

[0026] Example 1: Preparation and structural characterization of surface-modified starch nanospheres The preparation of surface-modified starch nanospheres in this embodiment includes the following steps: (1) Preparation of cross-linked starch nanospheres A 1000 mL four-necked flask equipped with a stirrer and thermometer was placed on an oil bath. 15.0 g of tapioca starch and 90.0 g of deionized water were slowly added, and the mixture was stirred and gelatinized at 45 °C for 30 minutes. 0.45 g of citric acid was added as a crosslinking agent, and 1% NaOH solution was slowly added dropwise to adjust the pH of the system to 10.0. The temperature was raised to 60 °C and the reaction was maintained at this temperature for 3 hours. After the reaction was completed, the system was cooled to room temperature, neutralized with dilute hydrochloric acid, centrifuged, washed repeatedly with deionized water three times, and then freeze-dried at -50 °C for 24 hours to obtain crosslinked starch nanosphere substrate. (2) Surface adsorption and hydrophobic modification The cross-linked starch nanosphere substrate obtained above was redispersed in deionized water at 65°C at a mass concentration of 8% to form a suspension; under high-speed stirring (1200 rpm), an aqueous solution of alkyl glycoside APG0810 (prepared to a mass concentration of 10% by weight of microspheres) of 15% by dry weight of microspheres was slowly added dropwise to the suspension, and the reaction was continuously stirred for 1.5 hours. (3) Drying and post-treatment The resulting suspension was centrifuged to collect the solid product, which was then vacuum-dried at 55°C to constant weight. The dried product was then gently pulverized using an air jet mill and passed through a 500-mesh sieve to obtain surface-modified starch nanospheres. Particle size analysis showed that the microspheres had a particle size distribution of 150-400 nm and a D90 / D10 value of 2.5, indicating uniform particle size distribution. Contact angle measurement showed a surface contact angle of 105°, demonstrating good hydrophobicity. Scanning electron microscopy (SEM) results are shown below. Figure 1 As shown.

[0027] Example 2: Preparation of water-based cutting fluid The preparation of the water-based cutting fluid in this embodiment includes the following steps: (1) Aqueous phase preparation Take a 2000 mL reactor equipped with a stirrer, add 600.0 g of deionized water, turn on the stirrer, and add 15.0 g of tannic acid and 15.0 g of sodium gluconate in sequence, stirring until completely dissolved; then add 60.0 g of polyglycerol, 30.0 g of alkyl glycoside APG0810 and 15.0 g of fatty alcohol polyoxyethylene ether FMEE, and stir thoroughly until the solution is homogeneous and transparent; (2) Preparation of oil phase In another container, mix 40.0 g of food-grade white mineral oil (NAP-free) with 8.0 g of cyclohexylamine carbonate until homogeneous; (3) Emulsification While the aqueous solution is being stirred at high speed, the oil phase mixture is slowly added to the aqueous phase to form a milky white emulsion. (4) Dispersion 10.0 g of the surface-modified starch nanospheres prepared in Example 1 were slowly and uniformly added to the emulsion system, and stirred continuously for 30 minutes to ensure full dispersion. (5) Dilution and pH adjustment Add the remaining 135.5 g of deionized water; slowly add approximately 6.5 g of 2-amino-2-methyl-1-propanol AMP-95, and monitor the pH meter in real time to precisely adjust the pH of the system to 7.8; (6) Added later Finally, slowly add 2.0 g of silicone defoamer and 1.5 g of isothiazolinone derivative Kathon LXE, and stir at low speed for 20 minutes to ensure complete homogeneity; (7) Discharge After filtration through a 5 μm filter bag, the water-based cutting fluid was obtained and labeled as sample S-1.

[0028] Example 3: Preparation of water-based cutting fluid The preparation of the water-based cutting fluid in this embodiment includes the following steps: Following the preparation method of Example 2, the amounts of each component were adjusted as follows: 5.0 g of surface-modified starch nanospheres, 50.0 g of polyglycerol, 30.0 g of food-grade white mineral oil, 10.0 g of tannic acid, 20.0 g of sodium gluconate, 5.0 g of cyclohexylamine carbonate, 20.0 g of alkyl glycoside APG0810, 20.0 g of fatty alcohol polyoxyethylene ether FMEE, 1.0 g of silicone defoamer, 1.0 g of isothiazolinone derivative Kathon LXE, an appropriate amount of 2-amino-2-methyl-1-propanol AMP-95 (approximately 4.0 g, adjusted to pH 7.5), and 845.0 g of deionized water.

[0029] After stirring evenly and filtering through a 5 μm filter bag, the water-based cutting fluid was obtained and labeled as sample S-2.

[0030] Example 4: Preparation of water-based cutting fluid The preparation of the water-based cutting fluid in this embodiment includes the following steps: Following the preparation method of Example 2, the amounts of each component were adjusted as follows: 15.0 g of surface-modified starch nanospheres, 80.0 g of polyglycerol, 50.0 g of food-grade white mineral oil, 20.0 g of tannic acid, 10.0 g of sodium gluconate, 10.0 g of cyclohexylamine carbonate, 40.0 g of alkyl glycoside APG0810, 10.0 g of fatty alcohol polyoxyethylene ether FMEE, 3.0 g of silicone defoamer, 2.0 g of isothiazolinone derivative Kathon LXE, an appropriate amount of 2-amino-2-methyl-1-propanol AMP-95 (approximately 9.0 g, adjusted to pH 8.0), and 751.0 g of deionized water.

[0031] After stirring evenly and filtering through a 5 μm filter bag, the water-based cutting fluid was obtained and labeled as sample S-3.

[0032] Comparative Example 1 Zirconia nanoparticles with a Mohs hardness >8 (D50 = 100nm) were used instead of the surface-modified starch nanospheres in this invention. The amount added was 10.0 g. The remaining components and preparation method were the same as in Example 2, and comparative sample C-1 was obtained.

[0033] Comparative Example 2 Without adding any microspheres or particulate lubricants, and with the remaining components and preparation method the same as in Example 2, comparative sample C-2 was obtained. Performance testing. Test Example 1: Friction Coefficient Test The friction coefficients of the water-based cutting fluid samples S-1 to S-3 prepared in Examples 2-4 of this invention, as well as the comparative samples C-1 and C-2, were tested using the following methods: Tribological evaluation was performed using an MS-T3001 friction and wear testing machine. The friction pair consisted of GCr15 bearing steel balls and a TC4 titanium alloy disk. The experimental conditions were fixed as follows: normal load 10 N, spindle speed 150 r / min, and rotation radius 3 mm (corresponding to a rotation diameter of 6 mm). Before testing, the friction pair was ultrasonically cleaned with petroleum ether and then ethanol to remove surface contaminants and obtain a consistent initial surface finish. After the sample was clamped, a small amount of the water-based cutting fluid to be tested was uniformly dropped onto the surface of the TC4 disk using a micro-syringe. The testing machine was then immediately started, and the change in the friction coefficient was continuously recorded over 30 minutes. After the test, the complete friction curve was saved, and the test results are shown in Figure 2-6.

[0034] Results analysis: Depend on Figure 2-6It can be seen that the friction coefficients of the water-based cutting fluid samples S-1 to S-3 obtained in Examples 2-4 are all lower than those of the comparative samples C-1 and C-2. Among them, Example 4 (S-3) has the lowest friction coefficient at 0.045, indicating that it has the best lubrication performance; Examples 2 (S-1) and 3 (S-2) have friction coefficients of 0.057 and 0.062 respectively, which are also significantly better than the comparative samples. In contrast, the friction coefficient of Comparative Example 2 (C-2) without added functional components is as high as 0.092, while that of Comparative Example 1 (C-1) is 0.071, further confirming that the cutting fluid prepared by the present invention can significantly reduce the friction coefficient and improve the lubrication effect.

[0035] Test Example 2: Rust Prevention and Foaming Test The rust-preventive properties and foaming properties of the water-based cutting fluid samples S-1 to S-3 prepared in Examples 2-4 of this invention, as well as the comparative samples C-1 and C-2, were tested using the following methods: Rust prevention performance was evaluated using the cast iron single-piece method according to GB / T 6144 standard. After grinding and cleaning, the standard cast iron test piece was immersed in the working fluid of the cutting fluid to be tested and placed in a humidification tank at (35±2)℃ for 24 hours. After the test, the test piece was removed, rinsed with deionized water, and the surface corrosion was immediately observed. Foaming performance was also tested according to GB / T 6144 standard. 100 mL of the working fluid was measured into a stoppered graduated cylinder, and after vigorous shaking at a constant temperature of (25±1)℃ for 10 minutes, the foam volume was immediately recorded. Corrosion resistance to aluminum was evaluated using the aluminum sheet immersion method. A standard aluminum sheet was completely immersed in the working fluid and kept at (55±2)℃ for 24 hours, after which surface changes were observed. The test results are shown in Table 1.

[0036] Table 1: Results of Rust Prevention and Foaming Tests Results Analysis: As shown in Table 1, the water-based cutting fluid samples S-1 to S-3 obtained in Examples 2-4 all achieved the highest standard of Grade A (rust-free) in the rust prevention performance test, and showed no corrosion to the aluminum material. It is particularly noteworthy that Comparative Example 2 (C-2), lacking the synergistic rust prevention system of this invention, had a rust prevention level reduced to Grade B (slight rust spots), which fully demonstrates the crucial role of the tannic acid-sodium gluconate-cyclohexylamine carbonate composite rust prevention system.

[0037] Regarding foaming properties, the foam volumes in Examples 2-4 were all controlled below 30 mL, demonstrating excellent foam suppression capabilities. In contrast, Comparative Example 1 (C-1), due to the use of hard zirconia particles, exhibited a foam volume as high as 45 mL, indicating that the presence of hard particles significantly exacerbates foam generation, affecting the stability of the processing and the cooling effect. All test samples showed no corrosion to aluminum, demonstrating the good compatibility of the formulation of this invention with sensitive metal materials.

[0038] Test Example 3: Biodegradability and Stability Test The biodegradability and storage stability of the water-based cutting fluid samples S-1 to S-3 prepared in Examples 2-4 of this invention, as well as the comparative samples C-1 and C-2, were tested using the following methods: Biodegradability was evaluated using the OECD 301F Mann respiration method. The test system consisted of a sealed respiration bottle with a pressure sensor, a magnetic stirrer, and a constant-temperature incubation device. Experimental conditions were fixed as follows: temperature (25±1)℃, inoculum was secondary effluent from an activated wastewater treatment plant, the test sample was used as the sole organic carbon source, and the incubation period was 28 days. Before testing, each sample was accurately weighed into a respiration bottle, and inorganic salt culture medium and inoculum were added. After sealing, the bottle was placed in a constant-temperature environment with continuous stirring. The oxygen consumption in each respiration bottle was automatically monitored and recorded using the pressure sensor. Data was collected daily until the end of the test, and the biodegradation rate was calculated based on the theoretical oxygen consumption. Simultaneously, accelerated stability testing was performed on sample S-1 from Example 2: the sample was placed in a 40℃ constant-temperature oven and observed continuously for 30 days. Samples were taken on days 0, 7, 15, and 30 to detect its appearance, pH value, rust prevention performance, and microsphere particle size distribution. The test results are shown in Table 2.

[0039] Table 2: Results of Biodegradability and Stability Tests Sample number 28-day biodegradation rate (%) Accelerated stability (40℃ / 30 days): Appearance / pH change / rust prevention retention Does it meet the rapid biodegradation standard? S-1 >92 No stratification, pH decrease of 0.2, rust prevention retention rate of 98%. yes S-2 >90 No stratification, pH decrease of 0.3, rust prevention retention rate of 96%. yes S-3 >91 No stratification, pH decrease of 0.3, rust prevention retention rate of 97%. yes C-1 <40 Slight precipitation, pH decrease of 0.8, rust prevention retention rate of 85%. no C-2 >90 No stratification, pH decrease of 0.4, rust prevention retention rate of 95%. yes Results analysis: As shown in Table 2, the 28-day biodegradation rates of the water-based cutting fluid samples S-1 to S-3 obtained in Examples 2-4 were significantly higher than those of the comparative sample C-1, and far exceeded the internationally recognized "rapid biodegradation" standard (60%). Among them, Example 2 (S-1) had the best biodegradation rate, reaching over 92%; Examples 3 (S-2) and 4 (S-3) had rates of 90% and 91%, respectively, both exhibiting excellent biodegradation performance. In contrast, the comparative sample 1 (C-1), which used zirconia nanoparticles, had a biodegradation rate of less than 40%, failing to meet the rapid biodegradation standard; while the comparative sample 2 (C-2), which did not use hard particles, recovered its biodegradation rate to over 90%. Meanwhile, accelerated stability testing results showed that after 30 days of storage at 40°C, the samples (S-1 to S-3) of this invention remained stable, with minimal degradation of key performance indicators, far superior to comparative sample C-1, demonstrating the excellent long-term storage stability and service life of the formulation and the prepared microspheres of this invention. These results fully demonstrate that the present invention has successfully achieved a significant improvement in the environmental friendliness of cutting fluids by using biodegradable starch nanospheres and environmentally friendly components, fundamentally solving the technical problem of environmental residues in traditional cutting fluids containing hard particles.

[0040] Test Example 4: Silicon Wafer Surface Cleanliness Test The surface cleanliness of water-based cutting fluid samples S-1 to S-3 prepared in Examples 2-4 of this invention, as well as comparative samples C-1 and C-2, was tested after processing. The testing method is as follows: Microscopic morphology and elemental composition analysis of the diced silicon wafer surface were performed using SEM / EDS. A Hitachi SU8010 field emission scanning electron microscope was used to observe the surface morphology of the silicon wafers, with an accelerating voltage of 5 kV and a working distance of 8 mm. Elemental analysis was performed using an Oxford X-MaxN 80 energy dispersive spectrometer, with a data acquisition time of 60 seconds and an analysis area of ​​100 μm × 100 μm. Sample preparation: After dicing 6-inch silicon wafers using various test cutting fluids in a multi-wire dicing machine, they were sequentially ultrasonically cleaned with deionized water and dried with nitrogen gas before being directly placed on the sample stage for testing, avoiding any surface contamination. The test results are shown in Table 3.

[0041] Table 3: Results of Residual Detection on Silicon Wafer Surface Sample number SEM morphology observation EDS Elemental Analysis Residue Evaluation S-1 The surface is clean and free of visible particles. No abnormal elements detected No hard particle residue S-2 The surface is clean and free of visible particles. No abnormal elements detected No hard particle residue S-3 The surface is clean and free of visible particles. No abnormal elements detected No hard particle residue C-1 Nanoscale particles dispersed on the surface Zr elemental characteristic peaks were detected. Zr residue detected C-2 The surface is clean and free of visible particles. No abnormal elements detected No hard particle residue Results analysis: As shown in Table 3, no hard particle residue was detected on the silicon wafer surface after treatment with the water-based cutting fluid samples S-1 to S-3 obtained in Examples 2-4. SEM images showed that the surface was clean and free of foreign contaminants. In contrast, Comparative Example 1 (C-1) clearly showed the characteristic peak of Zr element in EDS analysis, confirming that the zirconium oxide hard particles used in it detached during the cutting process and remained on the silicon wafer surface. Such metallic contaminants are absolutely unacceptable in semiconductor manufacturing processes and will directly lead to device performance degradation and yield reduction.

[0042] These results fully demonstrate that the present invention, using surface-modified starch nanospheres as a lubricating component, fundamentally solves the problem of silicon wafer surface contamination caused by traditional hard particle cutting fluids. While providing excellent lubrication performance, the starch microspheres are also biodegradable and can be completely removed after processing using standard cleaning processes, without introducing any metallic contaminants onto the silicon wafer surface, thus meeting the extreme requirements for material cleanliness in semiconductor manufacturing.

[0043] Those skilled in the art should note that the embodiments described in this invention are merely exemplary, and various other substitutions, changes, and improvements can be made within the scope of this invention. Therefore, this invention is not limited to the above embodiments, but is defined only by the claims.

Claims

1. An environmentally friendly, high-lubricity water-based cutting fluid for semiconductor cutting, characterized in that, It consists of the following components in parts by weight: 0.5–1.5 parts of cross-linked starch nanospheres modified with alkyl glycosides; Polyglycerol 5.0–8.0 parts; Food-grade white mineral oil, 3.0–5.0 parts; Tannic acid 1.0–2.0 parts; Sodium gluconate 1.0–2.0 parts; Cyclohexylamine carbonate 0.5–1.0 parts; Alkyl glycosides, 2.0–4.0 parts; 1.0 to 2.0 parts of fatty alcohol polyoxyethylene ether; 0.1 to 0.3 parts of silicone defoamer; 0.1–0.2 parts of isothiazolinone derivative; 0.5 to 1.5 parts of 2-amino-2-methyl-1-propanol; 65.0–85.0 parts of deionized water; The 2-amino-2-methyl-1-propanol is used to adjust the pH of the water-based cutting fluid to 7.5-8.

0.

2. The water-based cutting fluid according to claim 1, characterized in that, The cross-linked starch nanospheres modified with alkyl glycosides have a particle size of 100–500 nm and a surface contact angle ≥90°.

3. The water-based cutting fluid according to claim 1 or 2, characterized in that, The alkyl glycoside-modified cross-linked starch nanospheres were prepared by a method comprising the following steps: (1) Preparation of cross-linked starch nanospheres: Natural starch was dispersed in deionized water and stirred and gelatinized at 40-50℃; a cross-linking agent was added and the pH of the system was adjusted to 9-11, and the reaction was carried out at 55-65℃ for 2-4 hours; after the reaction was completed, the cross-linked starch nanosphere substrate was obtained by post-treatment. (2) Surface adsorption and hydrophobic modification: The microsphere substrate obtained in step (1) is redispersed in deionized water at 60-70℃, an alkyl glycoside aqueous solution is added, and the reaction is stirred for 1-2 hours; (3) Drying and post-treatment: The reaction product is centrifuged, vacuum dried, air-jet pulverized and passed through a 400-600 mesh sieve to obtain the surface-modified starch nanospheres.

4. The water-based cutting fluid according to claim 3, characterized in that, In step (1), the crosslinking agent is citric acid or sodium trimetaphosphate, and the amount added is 1% to 5% of the dry weight of starch.

5. The water-based cutting fluid according to claim 1, characterized in that, The alkyl glycoside is APG0810.

6. A method for preparing a water-based cutting fluid as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Preparation of aqueous phase: Mix some deionized water with tannic acid, sodium gluconate, polyglycerol, alkyl glycoside and fatty alcohol polyoxyethylene ether, and stir until completely dissolved to obtain aqueous phase; (2) Preparation of oil phase: Food-grade white mineral oil and cyclohexylamine carbonate are mixed evenly to obtain the oil phase; (3) Emulsification: The oil phase is added to the aqueous phase under stirring to form an emulsion; (4) Dispersion: Add cross-linked starch nanospheres modified with alkyl glycosides to the emulsion, disperse evenly, and then add the remaining deionized water; (5) pH adjustment: Adjust the pH of the system to 7.5-8.0 using 2-amino-2-methyl-1-propanol; (6) Add: Add organosilicon defoamer and isothiazolinone derivative, stir evenly, and the water-based cutting fluid is obtained.

7. The application of a water-based cutting fluid as described in any one of claims 1 to 5 in the cutting and processing of semiconductor materials.

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