Method for measuring concentration of cerium oxide polishing liquid and method for measuring effective use life of polishing liquid

Abstract

The present application belongs to the technical field of precision processing scene of flexible glass, semiconductor shallow trench isolation and other cerium oxide grinding fluid concentration measurement method. The calibration curve is established; the standard density-solid content calibration curve is drawn with solid content as the ordinate and density as the abscissa, and the linear regression equation is established; the rapid detection; the calibration curve calibration: the synchronous sample of rapid detection is selected once a period, and the drying method is used for measurement; the drying method measurement result and the same period rapid detection result are compared, if the deviation is less than ±1%, it is not necessary to redraw the calibration curve, if the deviation is more than ±1%, the calibration curve is redrawn, and the linear regression equation is updated. The cerium oxide grinding fluid concentration measurement method of the present application not only retains the real-time of density method, but also ensures the measurement accuracy through the drying method calibration every week, solves the problem that the existing method is "precise and fast".

Description

Technical Field

[0001] This invention belongs to the technical field of precision processing scenarios such as flexible glass and semiconductor shallow trench isolation (STI). More specifically, it relates to a method for measuring the concentration of cerium oxide polishing slurry. This invention also relates to a method for measuring the effective service life of cerium oxide polishing slurry. Background Technology

[0002] Cerium oxide polishing slurries are widely used in chemical mechanical polishing (CMP) processes due to their high polishing selectivity and excellent surface finish, especially in precision machining applications such as flexible glass and semiconductor shallow trench isolation (STI). The concentration (solid content) of the polishing slurry directly determines the polishing efficiency and surface roughness, while the effective lifespan of the slurry is related to processing cost control and product quality stability. If the concentration of the polishing slurry deviates from the process threshold, it will lead to abnormal polishing rates and increased surface scratches; if the polishing slurry is used beyond its lifespan, it will cause problems such as edge chipping of the workpiece and decreased surface accuracy, seriously affecting product yield.

[0003] Existing methods for measuring the concentration of cerium oxide grinding slurry mainly fall into two categories: the drying method and the density method. While the drying method provides accurate measurements, it is cumbersome and time-consuming (usually requiring 2-4 hours), making it unsuitable for real-time monitoring in production settings. The density method relies on a density-solid content calibration curve; however, particle sedimentation and impurities in the grinding slurry can easily lead to calibration deviations, and the lack of a standardized procedure for regular calibration makes it difficult to guarantee measurement accuracy.

[0004] Regarding the determination of the effective service life of polishing slurries, existing technologies mostly rely on single indicators such as polishing time or surface roughness, failing to form a multi-dimensional comprehensive assessment system. For example, some methods only monitor changes in polishing rate to determine the end of the service life, ignoring key influencing factors such as changes in particle size distribution and edge chipping, leading to inaccurate service life determination. This results in either premature replacement leading to waste of polishing slurry or prolonged use affecting product quality. Furthermore, existing service life testing is not linked to concentration monitoring data, failing to reflect the coupled impact of concentration fluctuations on service life, making it difficult to achieve precise management of the polishing slurry throughout its entire lifecycle.

[0005] In summary, current methods for measuring concentration using hydrometers have relatively low accuracy. Existing methods for measuring cerium oxide grinding slurry concentration mainly fall into two categories: the drying method and the density method. While the drying method offers precise measurements, it is cumbersome and time-consuming, failing to meet the real-time monitoring needs of production sites. The density method relies on a density-solid content calibration curve; however, particle sedimentation and impurities in the grinding slurry can easily lead to calibration deviations, and the lack of a standardized, periodic calibration process makes it difficult to guarantee measurement accuracy. Therefore, there is room for improvement.

[0006] Existing technology includes a patent titled "Cerium Oxide Powder for Single-Component CMP Slurry and its Preparation Method, Slurry Composition, and Shallow Trench Isolation Method Using the Slurry," with publication number "101258106B." This patent discloses cerium oxide powder for single-component CMP slurry, wherein the cerium oxide powder has a specific surface area of ​​5 m² / g or greater, and the volume fraction of pores with a diameter greater than or equal to 3 nm is in the ratio of 8:2 to 2:8 to the volume fraction of pores with a diameter less than 3 nm. This invention also discloses a method for preparing the aforementioned cerium oxide powder, a single-component CMP slurry containing the aforementioned cerium oxide powder as an abrasive material, and a method for shallow trench isolation using the single-component CMP slurry. The CMP slurry uses cerium oxide powder with a high pore volume fraction and low strength, obtained through a low-temperature calcination step, an optional pulverization step, and a high-temperature calcination step, as an abrasive material. Even when the CMP slurry is provided in the form of a single-component CMP slurry, it does not produce cerium oxide powder precipitation. Furthermore, the single-component CMP slurry provides a significantly reduced polishing rate for the silicon nitride layer and an increased polishing selectivity for the silicon oxide / silicon nitride layer. However, this technique does not address the technical problems or solutions of this application. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for measuring the concentration of cerium oxide grinding slurry that combines accuracy and real-time performance, thereby solving the problems of low measurement efficiency, single judgment index, and inaccurate control in the existing technology.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to a method for measuring the concentration of cerium oxide grinding slurry, the specific steps of which are as follows: S1. Calibration Curve Establishment: Take freshly prepared cerium oxide grinding slurry from the same batch and measure the solid content of multiple samples with different dilution ratios using the drying method, while simultaneously measuring the density of each sample; plot the standard density-solid content calibration curve with solid content as the ordinate and density as the abscissa, and establish a linear regression equation: y = ax + b; Where y is the solid content, x is the density, and a and b are calibration coefficients; S2. Rapid detection: Take a well-stirred grinding liquid sample, measure its density using a densitometer, substitute it into the above linear regression equation, and calculate the real-time solid content. The solid content is the concentration. S3. Calibration Curve Calibration: Periodically select a synchronous sample for rapid testing and measure it using the drying method; The drying conditions are: high temperature environment, forced air drying, maintained for a set time until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying. Compare the results of the drying method measurement with the results of the rapid detection at the same time. If the deviation is less than ±1%, there is no need to redraw the calibration curve. If the deviation exceeds ±1%, the calibration curve should be redrawn and the linear regression equation updated.

[0009] When measuring the solid content of multiple samples with different dilution ratios using the drying method, The drying conditions are: forced air drying at 105±2℃ for 2~4 hours until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying.

[0010] When establishing the calibration curve, take freshly prepared cerium oxide grinding slurry from the same batch and measure the solid content of at least five samples with different dilution ratios by the drying method.

[0011] On-site rapid inspection: Inspection frequency control: A rapid inspection is performed every 50 workpieces processed, and the measurement data and inspection time are recorded.

[0012] On-site rapid testing: Simultaneous samples for rapid testing are selected once a week and measured accurately using the drying method; the drying conditions are: 105±2℃ forced air drying for 2~4 hours until constant weight, and the solid content calculation formula is: solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample + weighing bottle, and m3 is the total mass after drying.

[0013] Calibration curve establishment: The dilution ratios of multiple samples with different dilution ratios were measured using the drying method. The dilution ratios are as follows: 1, 1:19, diluted 20 times, theoretically low solids content; 2, 1:9, diluted 10 times; 3, 1:4, diluted 5 times; 4. 1:2, diluted 3 times; 5, 1:1, diluted 2 times; 6, 3:2, 60% of original solution; 7, 4:1, 80% of original solution; 8, 10:1, 90.9% of the original solution, close to the original solution.

[0014] The technical problem to be solved by the present invention is to provide a method for measuring the effective service life of cerium oxide polishing slurry that takes into account both accuracy and real-time performance, thereby solving the problems of low measurement efficiency, single judgment index, and inaccurate control in the existing technology.

[0015] S1. Establishing reference parameters: Process multiple batches of workpieces of the same specification using freshly prepared cerium oxide polishing slurry, and record the following reference parameters: Grinding efficiency benchmark: average grinding time t0 for a single workpiece; Surface quality benchmark values: surface roughness Ra0, maximum edge chipping size d0; Particle characteristic baseline value: Particle size distribution D500.

[0016] S2. Full lifecycle monitoring: The following indicators are monitored simultaneously, with each monitoring cycle consisting of 50 workpieces processed: real-time solid content of the grinding fluid, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50. Simultaneously record process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature (controlled at 20~25℃).

[0017] S3. Judgment Rules: The grinding fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Grinding time for a single workpiece t ≥ 1.2t0 (grinding efficiency decreases by more than 20%). Surface roughness Ra > upper limit of process requirements (e.g. Ra > 0.01 μm); Edge chipping size d > 5μm; S4. The cumulative number of workpieces processed or the cumulative running time from the time the new polishing slurry is put into use until it is determined to be ineffective is the effective service life of the cerium oxide polishing slurry under the current process conditions.

[0018] Alternatively, the polishing fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Particle size D50 change rate |(D50-D500) / D500|×100%>15%; Even after adjustments, the solid content could not be maintained within ±1% of the initial solid content.

[0019] Establishing baseline parameters: Process 3-5 batches of workpieces of the same specifications using freshly prepared cerium oxide polishing slurry and record the baseline parameters.

[0020] Full life cycle monitoring; with each monitoring cycle consisting of 50 workpieces processed, the following indicators are simultaneously monitored: real-time solid content of the grinding slurry, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50; process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature are recorded simultaneously, with the grinding temperature controlled at 20~25℃.

[0021] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The cerium oxide polishing slurry concentration measurement method described in this invention has a standardized operation process and clarifies key parameters such as detection frequency, calibration cycle, and judgment threshold, which facilitates its promotion and application in production sites. Through precise monitoring and control of the polishing slurry throughout its entire life cycle, it significantly improves the workpiece processing yield and reduces rework and scrap costs caused by polishing slurry problems, thus having significant economic value. Attached Figure Description

[0022] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a schematic diagram of the density-solid content calibration curve described in this invention; Detailed Implementation

[0023] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1 As shown, this invention provides a method for measuring the concentration of cerium oxide polishing slurry. The specific steps for measuring the concentration of cerium oxide polishing slurry are as follows: S1. Calibration Curve Establishment: The calibration curve is established by the operator. The operator takes freshly prepared cerium oxide grinding slurry from the same batch and measures the solid content of multiple samples with different dilution ratios using the drying method, while simultaneously measuring the density of each sample. The operator then plots a density-solid content calibration curve with solid content as the ordinate and density as the abscissa. A linear regression equation needs to be established during the calibration curve establishment process. y = ax + b; In the above formula, y is the solid content, x is the density, and a and b are calibration coefficients; S2. Rapid detection: Rapid detection is performed by the operator. The operator takes a well-stirred grinding liquid sample, uses a densitometer to measure its density x, obtains the density x data, substitutes it into the above linear regression equation, and calculates the real-time solid content y. The solid content y is the concentration. S3. Calibration Curve Calibration: The calibration curve needs to be calibrated by the operator. The operator should periodically select a synchronous sample for rapid testing and measure it using the drying method. The drying conditions are: high temperature environment, forced air drying, maintained for a set time until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying. Compare the results of the drying method measurement with the results of the rapid detection method from the same period. If the deviation is less than ±1%, there is no need to redraw the calibration curve. If the deviation exceeds ±1%, the calibration curve should be redrawn, and the linear regression equation should be updated. The calibration curve calibration operation is to improve measurement accuracy through correction.

[0024] The cerium oxide polishing slurry concentration measurement method described in this invention adopts a calibration curve establishment + rapid detection + periodic calibration approach. This retains the real-time performance of the density method (single detection time ≤ 5 minutes) while ensuring measurement accuracy (deviation ≤ ±1%) through weekly drying calibration. This solves the problem of existing methods where "accuracy and speed cannot be simultaneously achieved," meeting the real-time control requirements of production sites. The method of this invention can be applied to the concentration detection of different cerium oxide polishing slurries.

[0025] When measuring the solid content of multiple samples with different dilution ratios using the drying method, The drying conditions are: forced air drying at 105±2℃ for 2~4 hours until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying.

[0026] The above steps can be used to obtain the actual solid content values ​​of samples with different dilution ratios.

[0027] When establishing the calibration curve, take freshly prepared cerium oxide grinding slurry from the same batch and measure the solid content of at least five samples with different dilution ratios by the drying method.

[0028] On-site rapid inspection: Inspection frequency control: Perform a rapid inspection every 50 workpieces processed, and record the measurement data and inspection time. The above steps are repeated periodically on one side for later use. On-site rapid testing: Samples selected for rapid testing weekly are precisely measured using a drying method. Drying conditions are: 105±2℃ forced air drying for 2-4 hours until constant weight. The solid content calculation formula is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and weighing bottle, and m3 is the total mass after drying. This structure allows for on-site rapid testing weekly. The samples are dried using a drying method.

[0029] Calibration curve establishment: The dilution ratios of multiple samples with different dilution ratios were measured using the drying method. The dilution ratios are as follows: 1, 1:19, diluted 20 times, theoretically low solids content; 2, 1:9, diluted 10 times; 3, 1:4, diluted 5 times; 4. 1:2, diluted 3 times; 5, 1:1, diluted 2 times; 6, 3:2, 60% of original solution; 7, 4:1, 80% of original solution; 8, 10:1, 90.9% of the original solution, close to the original solution.

[0030] The technical problem to be solved by the present invention is to provide a method for measuring the effective service life of cerium oxide polishing slurry that takes into account both accuracy and real-time performance, thereby solving the problems of low measurement efficiency, single judgment index, and inaccurate control in the existing technology.

[0031] S1. Establishing reference parameters: Process multiple batches of workpieces of the same specification using freshly prepared cerium oxide polishing slurry, and record the following reference parameters: Grinding efficiency benchmark: average grinding time t0 for a single workpiece; Surface quality benchmark values: surface roughness Ra0, maximum edge chipping size d0; Particle characteristic baseline value: Particle size distribution D500.

[0032] S2. Full lifecycle monitoring: The following indicators are monitored simultaneously, with each monitoring cycle consisting of 50 workpieces processed: real-time solid content of the grinding fluid, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50. Simultaneously record process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature (controlled at 20~25℃).

[0033] S3. Judgment Rules: The grinding fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Grinding time for a single workpiece t ≥ 1.2t0 (grinding efficiency decreases by more than 20%). Surface roughness Ra > upper limit of process requirements (e.g. Ra > 0.01 μm); Edge chipping size d > 5μm.

[0034] S4. The cumulative number of workpieces processed or the cumulative running time from the time the new polishing slurry is put into use until it is determined to be ineffective is the effective service life of the cerium oxide polishing slurry under the current process conditions.

[0035] Alternatively, the polishing fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Particle size D50 change rate |(D50-D500) / D500|×100%>15%; Even after adjustments, the solid content could not be maintained within ±1% of the initial solid content.

[0036] In this invention, there are five conditions for determining that the polishing fluid has reached the end of its effective service life: Grinding time for a single workpiece t ≥ 1.2t0 (grinding efficiency decreases by more than 20%). Surface roughness Ra > upper limit of process requirements (e.g. Ra > 0.01 μm); Edge chipping size d > 5μm.

[0037] Particle size D50 change rate |(D50-D500) / D500|×100%>15%; Even after adjustments, the solid content could not be maintained within ±1% of the initial solid content.

[0038] If any one of these conditions is met, the grinding fluid can be considered to have reached the end of its effective service life.

[0039] The method for measuring the effective service life of cerium oxide polishing slurry of the present invention adopts a multi-dimensional comprehensive index system, covering four core dimensions: polishing efficiency, surface quality, particle characteristics, and concentration stability, thus avoiding the one-sidedness of judging by a single index. At the same time, it establishes a linkage analysis mechanism between concentration and service life, accurately reflecting the impact of concentration fluctuations on service life, making service life determination more scientific and accurate, and reducing polishing slurry waste and the risk of exceeding the service life.

[0040] Establishing baseline parameters: Machine 3-5 batches of workpieces of the same specification using freshly prepared cerium oxide polishing slurry, and record the baseline parameters. For the above structure, establishing baseline parameters requires multiple sets of data.

[0041] Full life cycle monitoring; with each monitoring cycle consisting of 50 workpieces processed, the following indicators are simultaneously monitored: real-time solid content of the grinding slurry, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50; process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature are recorded simultaneously, with the grinding temperature controlled at 20~25℃.

[0042] The cerium oxide polishing slurry concentration measurement method of this invention addresses a specific technical problem in a particular field: cerium oxide polishing slurry, due to its high polishing selectivity and excellent surface finish, is widely used in chemical mechanical polishing (CMP) processes, especially indispensable in precision machining scenarios such as flexible glass and semiconductor shallow trench isolation (STI). The concentration (solid content) of the polishing slurry directly determines the polishing efficiency and the surface roughness of the processed surface, while the effective service life of the polishing slurry is related to processing cost control and product quality stability. If the concentration of the polishing slurry deviates from the process threshold, it will lead to abnormal polishing rates and increased surface scratches; if the polishing slurry is used beyond its service life, it will cause problems such as workpiece edge chipping and decreased surface accuracy, seriously affecting product yield.

[0043] The shortcomings of existing methods lie in their reliance on single indicators such as grinding time or surface roughness to determine the effective lifespan of polishing slurries. These methods lack a comprehensive, multi-dimensional assessment system. For example, some methods determine the lifespan end solely by monitoring changes in grinding rate, neglecting crucial factors like particle size distribution variations and edge chipping. This leads to inaccurate lifespan determinations, resulting in either premature replacement and wasted slurry or prolonged use that impacts product quality. Furthermore, current lifespan monitoring methods are not linked to concentration monitoring data, failing to reflect the coupled impact of concentration fluctuations on lifespan and hindering precise control over the entire lifecycle of the polishing slurry.

[0044] Therefore, the purpose of this invention is to provide a concentration measurement method that balances accuracy and real-time performance, and to provide an effective service life determination method that balances accuracy and real-time performance, thereby solving the problems of low measurement efficiency, single determination index, and inaccurate control in the prior art.

[0045] The method for measuring the concentration of cerium oxide polishing slurry in this invention has a standardized operating procedure and clarifies key parameters such as detection frequency, calibration cycle, and judgment threshold, which facilitates its application in production sites. Through precise monitoring and control of the polishing slurry throughout its entire life cycle, the yield of workpiece processing is significantly improved, and the rework and scrap costs caused by polishing slurry problems are reduced, which has significant economic value.

[0046] The key point of this method for measuring the concentration of cerium oxide polishing slurry is to monitor the concentration of the polishing slurry in real time, ensure the stability of the concentration, guarantee the stability of the polishing volume of the polishing machine, improve production capacity, reduce the impact of changes in the concentration of the polishing slurry on dimensional accuracy, and reduce the variables affecting the dimensions of the machine.

[0047] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A method for measuring the concentration of cerium oxide grinding slurry, characterized in that: S1. Calibration Curve Establishment: Take freshly prepared cerium oxide grinding slurry from the same batch and measure the solid content of multiple samples with different dilution ratios using the drying method, while simultaneously measuring the density of each sample; plot the standard density-solid content calibration curve with solid content as the ordinate and density as the abscissa, and establish a linear regression equation: y = ax + b; Where y is the solid content, x is the density, and a and b are calibration coefficients; S2. Rapid detection: Take a well-stirred grinding liquid sample, measure its density using a densitometer, substitute it into the above linear regression equation, and calculate the real-time solid content. The solid content is the concentration. S3. Calibration Curve Calibration: Periodically select a synchronous sample for rapid testing and measure it using the drying method; The drying conditions are: high temperature environment, forced air drying, maintained for a set time until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying. Compare the results of the drying method measurement with the results of the rapid detection at the same time. If the deviation is less than ±1%, there is no need to redraw the calibration curve. If the deviation exceeds ±1%, the calibration curve should be redrawn and the linear regression equation updated.

2. The method for measuring the concentration of cerium oxide grinding slurry according to claim 1, characterized in that: When measuring the solid content of multiple samples with different dilution ratios using the drying method, The drying conditions are: forced air drying at 105±2℃ for 2~4 hours until constant weight. The formula for calculating solid content is: Solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample and the weighing bottle, and m3 is the total mass after drying.

3. The method for measuring the concentration of cerium oxide grinding slurry according to claim 1, characterized in that: When establishing the calibration curve, take freshly prepared cerium oxide grinding slurry from the same batch and measure the solid content of at least five samples with different dilution ratios by the drying method.

4. The method for measuring the concentration of cerium oxide grinding slurry according to claim 1, characterized in that: On-site rapid inspection: Inspection frequency control: A rapid inspection is performed every 50 workpieces processed, and the measurement data and inspection time are recorded.

5. The method for measuring the concentration of cerium oxide grinding slurry according to claim 1, characterized in that: On-site rapid testing: Simultaneous samples for rapid testing are selected once a week and measured accurately using the drying method; the drying conditions are: 105±2℃ forced air drying for 2~4 hours until constant weight, and the solid content calculation formula is: solid content (%) = (m3-m1) / (m2-m1)×100%, where m1 is the mass of the empty weighing bottle, m2 is the total mass of the sample + weighing bottle, and m3 is the total mass after drying.

6. The method for measuring the concentration of cerium oxide grinding slurry according to claim 1, characterized in that: Calibration curve establishment: The dilution ratios of multiple samples with different dilution ratios were measured using the drying method. The dilution ratios were as follows: 1, 1:19, diluted 20 times, theoretically low solids content; 2, 1:9, diluted 10 times; 3, 1:4, diluted 5 times; 4. 1:2, diluted 3 times; 5, 1:1, diluted 2 times; 6, 3:2, 60% of original solution; 7, 4:1, 80% of original solution; 8, 10:1, 90.9% of the original solution, close to the original solution.

7. A method for measuring the effective service life of cerium oxide polishing slurry, characterized in that: S1. Establishing reference parameters: Using freshly prepared cerium oxide polishing slurry, process multiple batches of workpieces of the same specifications and record the following reference parameters: Grinding efficiency benchmark: average grinding time t0 for a single workpiece; Surface quality benchmark values: surface roughness Ra0, maximum edge chipping size d0; Particle characteristic baseline value: Particle size distribution D500; S2. Full lifecycle monitoring: The following indicators are monitored simultaneously, with each monitoring cycle consisting of 50 workpieces processed: real-time solid content of the grinding fluid, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50. Simultaneously record process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature (controlled at 20~25℃); S3. Judgment Rules: The grinding fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Grinding time for a single workpiece t ≥ 1.2t0 (grinding efficiency decreases by more than 20%). Surface roughness Ra > upper limit of process requirements (e.g. Ra > 0.01 μm); Edge chipping size d > 5 μm; S4. The cumulative number of workpieces processed or the cumulative running time from the time the new polishing slurry is put into use until it is determined to be ineffective is the effective service life of the cerium oxide polishing slurry under the current process conditions.

8. The method for measuring the effective service life of cerium oxide polishing slurry according to claim 1, characterized in that: Alternatively, the polishing fluid is considered to have reached the end of its effective service life when any of the following conditions are met: Particle size D50 change rate |(D50-D500) / D500|×100%>15%; Even after adjustments, the solid content could not be maintained within ±1% of the initial solid content.

9. The method for measuring the effective service life of cerium oxide polishing slurry according to claim 1, characterized in that: Establishing baseline parameters: Process 3-5 batches of workpieces of the same specifications using freshly prepared cerium oxide polishing slurry and record the baseline parameters.

10. The method for measuring the effective service life of cerium oxide polishing slurry according to claim 1, characterized in that: Full life cycle monitoring; with each monitoring cycle consisting of 50 workpieces processed, the following indicators are simultaneously monitored: real-time solid content of the grinding slurry, grinding time t for a single workpiece, surface roughness Ra of the workpiece, edge chipping size d, and particle size D50; process parameters such as grinding slurry replenishment amount, circulation flow rate, and grinding temperature are recorded simultaneously, with the grinding temperature controlled at 20~25℃.

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