A partitioned liquid supply single-side polishing system and method for achieving high surface shape accuracy

Abstract

This invention discloses a zoned liquid supply single-sided polishing system and method for achieving high surface accuracy, belonging to the field of precision surface processing. The polishing system includes a workpiece rotation drive mechanism, a polishing disc, a polishing pad, and multiple liquid supply branches. By setting multiple liquid supply branches, this invention can control the flow rate and composition parameters of the polishing liquid at the contact interface between the polishing pad and the workpiece in zones, thereby actively regulating the material removal rate in different radial regions of the workpiece and achieving active convergence of the workpiece surface shape. This solves the defects of traditional edge-supply systems, which suffer from uneven and uncontrollable radial distribution of polishing liquid due to centrifugal force, and achieves precise control of the material removal rate distribution. Furthermore, this invention constructs a process database centered on the mapping relationship between process parameter combinations and material removal distribution, enabling the system to automatically match the optimal process parameter combination based on historical data, significantly reducing reliance on manual experience.

Description

Technical Field

[0001] This invention relates to the field of precision surface processing, and specifically to a partitioned liquid supply single-sided polishing system and method for achieving high surface accuracy. Background Technology

[0002] Polishing, a common precision surface finishing technique, is widely used in the surface processing of various materials such as metals, ceramics, and fused silica. Single-sided polishing not only aims to achieve an ultra-smooth surface quality but also to meet extremely high surface accuracy requirements. With the rapid development of the semiconductor and optics industries, increasingly stringent requirements have been placed on the surface accuracy of workpieces. For example, for photolithography lenses or extreme ultraviolet optical components, even nanometer-level surface deviations can lead to a significant decrease in system imaging quality. Therefore, selectively removing material and achieving global planarization during the polishing process is of great importance.

[0003] In single-sided polishing, the chemical components in the polishing slurry react with the workpiece surface to form a softer modified layer. Subsequently, the abrasive particles in the polishing slurry selectively remove this softened layer through mechanical friction. The alternating chemical and mechanical actions achieve material removal. Therefore, the polishing slurry is crucial to single-sided polishing technology, and its flow rate and composition significantly impact the material removal rate. For hard and brittle crystals such as KDP (potassium dihydrogen phosphate), silicon, and glass, the material removal rate is exceptionally sensitive to polishing slurry parameters (such as flow rate, pH value, oxidant concentration, abrasive particle size, and abrasive particle concentration). Even minor changes in the properties of the polishing slurry can significantly affect the chemical corrosion rate and mechanical removal rate, thus directly impacting material removal efficiency. For example, increasing the abrasive particle concentration increases the number of abrasive particles participating in effective micro-cutting per unit time, directly improving the mechanical removal rate; while increasing the oxidant concentration accelerates the formation rate of the oxide layer on the workpiece surface, creating favorable conditions for subsequent efficient mechanical removal.

[0004] However, existing technologies generally employ edge-supply methods, which have fundamental limitations. Especially when machining large workpieces, the strong centrifugal force generated by the high-speed rotation of the polishing disc makes it difficult for the polishing slurry to effectively penetrate and stably distribute in the central area of ​​the workpiece, resulting in a severe radial gradient in the slurry distribution. This inherent and uncontrollable uneven distribution places different radial positions of the workpiece in differentiated chemical-mechanical polishing environments, directly causing variations in material removal rates in the radial direction, making it difficult to guarantee surface accuracy. Particularly for workpieces with pre-existing surface errors, the material removal process under traditional slurry supply methods is essentially passive and uncontrolled. This method not only fails to specifically correct initial surface errors but also exacerbates them due to the inherently non-uniform material removal rate distribution, resulting in extremely low surface accuracy convergence efficiency during the polishing process. This severely restricts the surface controllability of single-sided polishing processes for high-precision optical components. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a partitioned liquid supply single-sided polishing system and method for achieving high surface shape accuracy. This system enables active and precise control of material removal distribution to achieve efficient and high-precision surface shape convergence.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] A zoned liquid supply single-sided polishing system for achieving high surface accuracy includes a workpiece rotation drive mechanism, a polishing disc, a polishing pad, and multiple liquid supply branches. The workpiece rotation drive mechanism is used to clamp and drive the workpiece to rotate. The polishing disc carries the polishing pad and rotates around its central axis. The disc body has at least three independent liquid supply zones in the radial direction. The polishing pad is fixed to the upper surface of the polishing disc and has through holes at positions corresponding to the liquid supply zones to ensure that the polishing liquid delivered from the liquid supply branches flows to the polishing interface. The number of the multiple liquid supply branches is the same as the number of liquid supply zones, and they correspond one-to-one. Each liquid supply branch includes a polishing liquid source, a fluid delivery mechanism, a flow control mechanism, and a flow channel. The liquid supply branch supplies polishing liquid to the corresponding liquid supply zone through the flow channel. The flow control mechanism is configured to independently adjust the polishing liquid flow rate of its respective liquid supply branch. The fluid delivery mechanism pumps the polishing liquid from the polishing liquid source of its respective liquid supply branch, and delivers it to the corresponding liquid supply zone through the flow control mechanism and the flow channel. The flow channel is a polishing fluid delivery path that connects the polishing fluid source, fluid delivery mechanism, flow control mechanism, and corresponding supply area of ​​the supply branch.

[0008] Furthermore, the liquid supply area is an annular area, concentric with the polishing disk, and multiple annular areas are evenly arranged radially along the polishing disk. The radius of the center circle of each liquid supply area is used as a positioning parameter to define the radius of the center circle of the innermost liquid supply area. R min The radius of the center circle of the outermost liquid supply area R max They respectively satisfy: R min = e -(3 / 4) R w , R max = e +(3 / 4) R w , in, R w Let be the radius of the workpiece. eThe center distance between the polishing disc and the workpiece is... R min and R max Within the defined interval, the radii of the central circles of all liquid supply zones form an arithmetic sequence.

[0009] Furthermore, each of the liquid supply zones is provided with at least three liquid supply holes; the liquid supply holes are through holes; multiple liquid supply holes in the same liquid supply zone are evenly distributed along the circumference, and the diameter of multiple liquid supply holes in the same liquid supply zone is the same.

[0010] Furthermore, the upper surface of the polishing pad is machined with a groove-shaped structure for conveying and distributing the polishing fluid. The pattern of the groove-shaped structure includes concentric rings, grids, spirals, or radial shapes; the groove depth of the groove-shaped structure is 0.2 to 0.5 times the thickness of the polishing pad. The groove-shaped structure intersects with the fluid supply area to ensure that the polishing fluid is effectively discharged and diffused from the fluid supply hole.

[0011] Furthermore, the material of the workpiece includes KDP crystal, silicon, and glass.

[0012] Furthermore, the fluid delivery mechanism includes a metering pump, a gear pump, a peristaltic pump, or a centrifugal pump; the flow control mechanism is an electro-hydraulic proportional control valve; the polishing liquid source is a storage tank containing polishing liquid, and the components of the polishing liquid include deionized water, abrasive particles, an oxidant, and a complexing agent; each polishing liquid source has polishing liquids with different composition parameters, including the pH value of the polishing liquid, the concentration of the oxidant, the concentration of the complexing agent, the particle size of the abrasive particles, and the concentration of the abrasive particles.

[0013] Furthermore, the end of the flow channel is connected to the bottom of the liquid supply hole, and the liquid supply branch rotates together with the polishing disc.

[0014] A method for achieving high surface accuracy through partitioned liquid supply single-sided polishing, using a partitioned liquid supply single-sided polishing system for high surface accuracy, is characterized by the following steps: S1. Construct a process database The workpiece surface is discretized and uniformly divided along the radius into... n A ring-shaped area; [to carry out] m A series of process experiments were conducted. In each experiment, the heights of at least 10 randomly distributed points within each annular zone on the workpiece surface were measured before and after polishing, and the average height difference of all points in each annular zone was calculated as the material removal amount for each annular zone. Let the material removal amount for the first annular zone be... Δ h 1. The amount of material removed from the second annular region is Δh 2. The amount of material removed from the third ring zone is Δh3. And so on; record and store the combination of polishing process parameters used in each group of experiments and the corresponding material removal distribution. Δh 1, Δh 2,…, Δh n Ultimately forming a group containing m The process database for group mapping data; n ≥3, m >50; S2. Measuring surface shape Measure the initial surface shape data of the workpiece to be polished and calculate the average height of each annular region. z 1, z 2,…, z n ; S3. Determine process parameters The remaining height of each ring after polishing z 1- Δh 1, z 2- Δh 2, …, z n - Δh n The constraint is that all values ​​are greater than zero. The objective is to minimize the difference between the maximum and minimum remaining heights in each annular region. m In the process database of the group mapping data, search and select the polishing process parameter combination that is closest to the target as the recommended polishing process parameter combination; S4. Polishing Perform the recommended combination of polishing process parameters to complete the polishing process; S5. Detection Measure the surface shape data of the polished workpiece. If the surface shape accuracy does not meet the standard, supplement the polishing process data into the process database and proceed to step S2 until the surface shape accuracy is qualified.

[0015] Furthermore, the polishing process parameter combination includes the flow rate and polishing fluid composition parameters of each of the fluid supply branches, polishing time, polishing disc rotation speed, workpiece rotation speed, and polishing pressure.

[0016] Furthermore, the composition parameters of the polishing fluid include at least the pH value, oxidant concentration, complexing agent concentration, abrasive particle size, and abrasive concentration.

[0017] The working principle of this invention is as follows: During single-sided polishing, the chemical components in the polishing slurry react with the workpiece surface to form a softer modified layer. Subsequently, the abrasive particles in the polishing slurry remove this softened layer through mechanical friction. The chemical and mechanical actions alternate, thereby achieving material removal. Therefore, the polishing slurry is crucial to single-sided polishing technology, and its flow rate and composition significantly affect the material removal rate. The polishing zone is divided into multiple independent supply zones, and each supply zone is configured with an independent supply branch. By precisely adjusting the flow rate and composition parameters of the polishing slurry in each branch, the chemical corrosion rate and mechanical friction intensity in different radial regions of the workpiece can be actively controlled, thereby achieving precise control of the material removal rate in each region. For example, if the workpiece exhibits a concave shape with a low center and high edges, the abrasive and oxidant concentrations in the corresponding edge region can be independently increased to increase the number of abrasive particles participating in effective cutting and accelerate the formation of the surface modified layer, thereby improving the material removal efficiency in that region and causing the workpiece surface shape to converge. To overcome the randomness and experience dependence in the polishing process, this invention further proposes a surface shape control method: based on the partitioned liquid supply device, a systematic process experiment is conducted to construct a process database with the mapping relationship between process parameter combinations and material removal distribution as the core. By accurately measuring the initial surface shape data of the workpiece to be polished, the optimal process parameter combination is matched in the process database, thereby achieving high-precision and high-efficiency convergence control of the workpiece surface shape error.

[0018] Compared with the prior art, the present invention has the following significant advantages: 1. This invention enables independent zoned control of the polishing slurry supply, thereby actively regulating the material removal rate in different radial regions of the workpiece. By setting up multiple independent supply branches, the flow rate and composition parameters of each branch can be independently adjusted, thus actively regulating the material removal rate in different radial regions of the workpiece. This fundamentally solves the defects of traditional edge-supply systems, where the radial distribution of the polishing slurry is uneven and uncontrollable due to centrifugal force, achieving precise control over the material removal rate distribution.

[0019] 2. Traditional methods heavily rely on operator experience for trial-and-error iteration. This invention constructs a process database centered on the mapping relationship between process parameter combinations and material removal distribution, enabling the system to automatically match the optimal process parameter combinations based on historical data, significantly reducing reliance on human experience. Attached Figure Description

[0020] This invention is accompanied by Figure 6 Zhang, of which: Figure 1 This is a schematic diagram of the partitioned liquid supply single-sided polishing system of the present invention.

[0021] Figure 2 This is a top view of the polishing disc of the present invention.

[0022] Figure 3 This is a top view of the polishing pad of the present invention.

[0023] Figure 4 This is a flowchart of the surface shape control method of the present invention.

[0024] Figure 5 This is a schematic diagram showing the division of the workpiece's annular region.

[0025] Figure 6 This is a schematic diagram of the workpiece's contours before and after polishing.

[0026] In the figure: 1. Workpiece rotation drive mechanism; 2. Workpiece; 201. First ring area; 202. Second ring area; 203. Third ring area; 3. Polishing disc; 301. First liquid supply area; 302. Second liquid supply area; 303. Third liquid supply area; 4. Polishing pad; 5. Liquid supply branch; 501. Polishing liquid source; 502. Fluid conveying mechanism; 503. Flow control mechanism; 504. Flow channel; 6. Liquid supply hole. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0028] like Figures 1 - 3 As shown, a single-sided polishing system with zoned liquid supply for achieving high surface accuracy includes a workpiece rotation drive mechanism 1, a polishing disc 3, a polishing pad 4, and three liquid supply branches 5. The workpiece rotation drive mechanism 1 is used to clamp and drive the workpiece 2 to rotate. The polishing disc 3 is used to carry the polishing pad 4 and rotate around its central axis. The disc body of the polishing disc 3 is provided with three independent liquid supply zones in the radial direction. The polishing pad 4 is fixed to the upper surface of the polishing disc 3 and has through holes at the positions corresponding to the liquid supply zones of the polishing disc 3 to ensure that the polishing liquid delivered from the liquid supply branches 5 flows to the polishing interface. There are three liquid supply branches 5, each corresponding to one of the liquid supply zones. Each liquid supply branch 5 includes a polishing liquid source 501, a fluid delivery mechanism 502, a flow control mechanism 503, and a flow channel 504. The liquid supply branch 5 supplies polishing liquid to the corresponding liquid supply zone through the flow channel 504. The flow control mechanism 503 is configured to independently adjust the polishing liquid flow rate of its respective liquid supply branch 5. The fluid delivery mechanism 502 is used to pump the polishing slurry from the polishing slurry source 501 of the supply branch 5, and deliver it to the corresponding supply area via the flow control mechanism 503 and the flow channel 504. The flow channel 504 is a polishing slurry delivery path connecting the polishing slurry source 501 of the supply branch 5, the fluid delivery mechanism 502, the flow control mechanism 503, and the corresponding supply area.

[0029] The liquid supply area is an annular area, concentric with the polishing disk 3. Three annular areas are evenly arranged radially along the polishing disk 3, with the radius of the center circle of each liquid supply area used as the positioning parameter; [The last part, "Setting," appears to be an error and doesn't need a direct translation.] R w The radius of the workpiece 2 is set as follows: e The center distance between the polishing disc 3 and the workpiece 2 is [missing information]; the innermost liquid supply area is the third liquid supply area 303, and its central circle radius is [missing information]. e -(3 / 4) R w The outermost liquid supply area is the first liquid supply area 301, and its central circle radius is... e +(3 / 4) R w The intermediate liquid supply area is the second liquid supply area 302, and its central circle radius is... e .

[0030] Each of the liquid supply zones is provided with eight liquid supply holes 6; the liquid supply holes 6 are through holes; the eight liquid supply holes 6 in the same liquid supply zone are evenly distributed in the circumferential direction, and the eight liquid supply holes 6 in the same liquid supply zone have the same diameter.

[0031] The upper surface of the polishing pad 4 is machined with a groove-shaped structure for conveying and distributing polishing fluid. The groove-shaped structure has a grid pattern, and the groove depth is 0.2 to 0.5 times the thickness of the polishing pad 4. The groove-shaped structure intersects with the fluid supply area to ensure that the polishing fluid is effectively discharged and diffused from the fluid supply hole 6.

[0032] The material of the workpiece 2 is silicon.

[0033] The fluid delivery mechanism 502 is a metering pump; the flow control mechanism 503 is an electro-hydraulic proportional control valve; the polishing liquid source 501 is a storage tank containing polishing liquid, and the components of the polishing liquid include deionized water, abrasive particles, oxidant, and complexing agent; each polishing liquid source 501 has polishing liquid with different composition parameters, including the pH value of the polishing liquid, the concentration of oxidant, the concentration of complexing agent, the particle size of abrasive particles, and the concentration of abrasive particles.

[0034] The end of the flow channel 504 is connected to the bottom of the liquid supply hole 6, and the liquid supply branch 5 rotates together with the polishing disc 3.

[0035] The polishing pad 4 has a thickness of 0.8~5 mm, a groove width of 1~8 times the groove depth, and a groove spacing of 0.1~0.3 times the radius of the polishing pad 4.

[0036] Figure 4 This is a flowchart of the surface shape control method of the present invention, which uses a partitioned liquid supply single-sided polishing system to achieve high surface shape accuracy for polishing. The method is characterized by the following steps: S1. Construct a process database The surface of workpiece 2 is discretized and uniformly divided into three annular regions along the radius; [The process is then carried out.] m A series of process experiments were conducted. In each experiment, the heights of at least 10 randomly distributed points within each annular zone on the surface of workpiece 2 before and after polishing were measured, and the average height difference of all points in each annular zone was calculated as the material removal amount for each annular zone. Let the material removal amount for the first annular zone 201 be... Δh 1. The amount of material removed from the second annular region 202 is: Δh 2. The amount of material removed from the third ring zone region 203 is Δh 3. Record and store the polishing process parameter combinations used in each group of experiments and the corresponding material removal distribution. Δh 1, Δh 2, Δh 3. Ultimately forming a system containing m The process database for group mapping data; m >50; S2. Measuring surface shape Measure the initial surface shape data of the workpiece 2 to be polished, and calculate the average height of each annular region. z 1, z 2, z 3; S3. Determine process parameters The remaining height of each ring after polishing z 1- Δh 1, z 2- Δh 2, z 3- Δh The constraint is that all three remain greater than zero. The objective is to minimize the difference between the maximum and minimum remaining heights in each annular region. m In the process database of the group mapping data, search and select the polishing process parameter combination that is closest to the target as the recommended polishing process parameter combination; S4. Polishing Perform the recommended combination of polishing process parameters to complete the polishing process; S5. Detection Measure the surface shape data of workpiece 2 after polishing. If the surface shape accuracy does not meet the standard, supplement the polishing process data into the process database and proceed to step S2 until the surface shape accuracy is qualified.

[0037] The polishing process parameter combination includes the flow rate and polishing fluid composition parameters of each of the liquid supply branches 5, polishing time, polishing disc 3 rotation speed, workpiece 2 rotation speed, and polishing pressure.

[0038] The composition parameters of the polishing fluid include at least the pH value, oxidant concentration, complexing agent concentration, abrasive particle size, and abrasive concentration.

[0039] Figure 5 The diagram shows the workpiece divided into three annular regions along the radius: the first annular region 201, the second annular region 202, and the third annular region 203.

[0040] Figure 6 This is a schematic diagram of the workpiece's outline before and after polishing. The average height of each ring in the workpiece 2 to be polished is ( z 1, z 2, z 3) To minimize the difference between the maximum and minimum remaining heights in each annular region, the polishing process parameter combination closest to this objective is searched and selected from the process database as the recommended polishing process parameter combination. The material removal rate distribution is ( Δh 1, Δh 2, Δh 3), the remaining height of each ring after polishing of the final workpiece 2 is ( z 1- Δh 1, z 2- Δh 2, z 3- Δ h 3).

[0041] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. A zoned liquid supply single-sided polishing system for achieving high surface accuracy, characterized in that: The system includes a workpiece rotation drive mechanism (1), a polishing disc (3), a polishing pad (4), and multiple liquid supply branches (5). The workpiece rotation drive mechanism (1) is used to clamp and drive the workpiece (2) to rotate. The polishing disc (3) is used to carry the polishing pad (4) and rotate around its central axis. The disc body of the polishing disc (3) has at least three independent liquid supply areas in the radial direction. The polishing pad (4) is fixed to the upper surface of the polishing disc (3) and has through holes at the positions corresponding to the liquid supply areas of the polishing disc (3) to ensure that the polishing liquid delivered from the liquid supply branches (5) flows to the polishing interface. The number of the multiple liquid supply branches (5) is the same as the number of liquid supply areas and they correspond one-to-one. Each liquid supply branch (5) includes a polishing liquid source (501). The fluid delivery mechanism (502), the flow control mechanism (503), and the flow channel (504) are configured to independently regulate the flow rate of the polishing fluid in the supply branch (5); the fluid delivery mechanism (502) is used to pump the polishing fluid from the polishing fluid source (501) in the supply branch (5), and deliver it to the corresponding supply area through the flow control mechanism (503) and the flow channel (504); the flow channel (504) is a polishing fluid delivery path connecting the polishing fluid source (501), the fluid delivery mechanism (502), the flow control mechanism (503), and the corresponding supply area in the supply branch (5).

2. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: The liquid supply area is an annular area and concentric with the polishing disk (3). Multiple annular areas are evenly arranged radially along the polishing disk (3). The radius of the center circle of each liquid supply area is used as the positioning parameter to define the radius of the center circle of the innermost liquid supply area. R min The radius of the center circle of the outermost liquid supply area R max They respectively satisfy: R min = e -(3 / 4) R w , R max = e +(3 / 4) R w , in, R w The radius of the workpiece (2) is e The center distance between the polishing disk (3) and the workpiece (2) is... R min and R max Within the defined interval, the radii of the central circles of all liquid supply zones form an arithmetic sequence.

3. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: Each of the liquid supply zones is provided with at least three liquid supply holes (6); the liquid supply holes (6) are through holes; multiple liquid supply holes (6) in the same liquid supply zone are evenly distributed along the circumference, and the diameter of multiple liquid supply holes (6) in the same liquid supply zone is the same.

4. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: The upper surface of the polishing pad (4) is processed with a groove structure for conveying and distributing polishing liquid. The pattern of the groove structure includes concentric rings, grids, spirals or radial shapes. The groove depth of the groove structure is 0.2 to 0.5 times the thickness of the polishing pad (4). The groove structure intersects with the liquid supply area to ensure that the polishing liquid is effectively discharged and diffused from the liquid supply hole (6).

5. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: The materials of the workpiece (2) include KDP crystal, silicon, and glass.

6. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: The fluid delivery mechanism (502) includes a metering pump, a gear pump, a peristaltic pump, or a centrifugal pump; the flow control mechanism (503) is an electro-hydraulic proportional control valve; the polishing liquid source (501) is a storage tank containing polishing liquid, the components of which include deionized water, abrasive particles, oxidant, and complexing agent; each polishing liquid source (501) has a polishing liquid with different composition parameters, the composition parameters including the pH value of the polishing liquid, the concentration of oxidant, the concentration of complexing agent, the particle size of abrasive particles, and the concentration of abrasive.

7. The partitioned liquid supply single-sided polishing system for achieving high surface accuracy according to claim 1, characterized in that: The end of the flow channel (504) is connected to the bottom end of the liquid supply hole (6), and the liquid supply branch (5) rotates together with the polishing disc (3).

8. A method for single-sided polishing with partitioned liquid supply to achieve high surface accuracy, comprising polishing using the partitioned liquid supply single-sided polishing system for achieving high surface accuracy as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Construct a process database Discretize the surface of the workpiece (2) and divide it uniformly along the radius into n A ring-shaped area; [to carry out] m Group process experiments; in each group of experiments, the height of at least 10 points randomly distributed within each ring zone on the surface of the workpiece (2) before and after polishing was measured, and the average height difference of all points in each ring zone was calculated as the material removal amount of each ring zone; let the material removal amount of the first ring zone (201) be... Δh 1. The material removal amount in the second annular region (202) is Δh 2. The material removal amount in the third ring zone region (203) is Δh 3. And so on; record and store the combination of polishing process parameters used in each group of experiments and the corresponding material removal distribution. Δ h 1, Δh 2,…, Δh n Ultimately forming a group containing m The process database for group mapping data; n ≥3, m >50; S2. Measuring surface shape Measure the initial surface shape data of the workpiece (2) to be polished, and calculate the average height of each annular region. z 1, z 2,…, z n ; S3. Determine process parameters The remaining height of each ring after polishing z 1- Δh 1, z 2- Δh 2, …, z n - Δh n The constraint is that all values ​​are greater than zero. The objective is to minimize the difference between the maximum and minimum remaining heights in each annular region. m In the process database of the group mapping data, search and select the polishing process parameter combination that is closest to the target as the recommended polishing process parameter combination; S4. Polishing Perform the recommended combination of polishing process parameters to complete the polishing process; S5. Detection Measure the surface shape data of the polished workpiece (2). If the surface shape accuracy does not meet the standard, the polishing process data is added to the process database and the process is transferred to step S2 until the surface shape accuracy is qualified.

9. The method for achieving high surface accuracy through partitioned liquid supply single-sided polishing according to claim 8, characterized in that: The polishing process parameter combination includes the flow rate and polishing fluid composition parameters of each of the liquid supply branches (5), polishing time, polishing disc (3) rotation speed, workpiece (2) rotation speed, and polishing pressure.

10. The method for achieving high surface accuracy through partitioned liquid supply for single-sided polishing according to claim 9, characterized in that: The composition parameters of the polishing fluid include at least the pH value, oxidant concentration, complexing agent concentration, abrasive particle size, and abrasive concentration.

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