A high-precision polishing method for RB-SiC mirror batch

Abstract

A high-efficiency, high-precision surface polishing method for batch production of RB-SiC galvanometers, belonging to the field of optical precision manufacturing, includes: preparing a combined tooling: the combined tooling includes a flat substrate and pressure blocks of different masses. The polishing surface of the flat substrate is machined with nested grooves for accommodating the galvanometers. A circular hole corresponding to the center position of each nested groove is opened on the loading surface of the flat substrate, extending to the bottom of the nested groove. A pressure block is independently placed in each circular hole to apply polishing pressure to the galvanometer in that nested groove; multiple galvanometers are placed one by one into the nested grooves, and a pressure block of selected mass is placed in the circular hole corresponding to each galvanometer. The pressure block applies pressure to the galvanometer by its own weight; the combined tooling with the galvanometers and pressure blocks is placed on a polishing machine for batch ultra-smooth flat polishing. This invention combines uniform pressure loading technology and ultra-smooth flat polishing process to achieve high-efficiency, high-precision, and high-consistency batch polishing of galvanometers.

Description

Technical Field

[0001] This invention belongs to the field of optical precision manufacturing technology, specifically relating to a method for high-efficiency, high-precision surface polishing of RB-SiC galvanometers in batches. Background Technology

[0002] As a core scanning component in lidar, laser projection, and precision machining equipment, the surface quality of the laser galvanometer directly affects the reflection efficiency and imaging accuracy of the optical system. With the rapid development of laser technology, the surface accuracy requirements for laser galvanometers are increasing: the surface shape accuracy is required to be better than 1 / 10λ (PV value, λ=632.8nm), and the surface roughness is required to be better than 0.2nm (RMS).

[0003] Silicon carbide (SiC) has become the preferred substrate for high-end galvanometers due to its excellent properties such as high specific stiffness, low coefficient of thermal expansion, and good thermal conductivity. Among them, reaction-bonded silicon carbide (RB-SiC) has significant advantages over SSiC and CVD SiC, such as lower manufacturing cost, shorter cycle time, and near-net-shape fabrication of complex shapes, making it particularly suitable for the mass production of small, precision components such as galvanometers.

[0004] However, the high hardness (Mohs hardness 9.2~9.5) and multiphase composite structure (coexistence of Si and SiC phases) of RB-SiC pose significant challenges to ultra-precision polishing. Currently, high-precision polishing of RB-SiC mainly faces the following problems:

[0005] 1. Low single-piece processing efficiency: Existing methods mostly employ single-piece clamping and polishing, which is insufficient to meet the mass production requirements of RB-SiC galvanometers. Even with computer-controlled optical surface forming (CCOS) technology, the single-piece processing cycle remains long.

[0006] 2. Clamping stress causes surface distortion: Traditional mechanical clamping methods apply clamping force to ultra-thin RB-SiC galvanometers (thickness typically <3mm), causing elastic deformation of the mirror surface. After polishing, the clamping force is removed, and the mirror surface springs back, resulting in a loss of surface accuracy.

[0007] 3. Inaccurate pressure control: When applying polishing pressure to the RB-SiC galvanometer, the existing method lacks the ability to finely control the pressure in different zones, making it difficult to compensate for the small morphological errors of a single RB-SiC galvanometer with local pressure.

[0008] 4. Batch Consistency Issues: As a dynamic scanning element, the RB-SiC galvanometer requires extremely high consistency in weight (affecting rotational inertia) and surface shape among batches of products. Traditional polishing methods struggle to achieve high consistency control across batches.

[0009] 5. RB-SiC Surface Defect Treatment: The inherent Si / SiC two-phase structure and micropore defects on the RB-SiC surface make it difficult to obtain an ultra-smooth surface using traditional polishing processes, requiring the combination of surface modification or special polishing processes.

[0010] Therefore, developing a batch-efficient and high-precision polishing method suitable for RB-SiC galvanometers to achieve a surface shape accuracy (PV) better than 1 / 10λ and a surface roughness (RMS) less than 0.2nm, while ensuring the weight and surface shape consistency of batch products, is a major technical problem that urgently needs to be solved in this field. Summary of the Invention

[0011] This invention aims to provide a high-efficiency, high-precision polishing method for batch polishing of RB-SiC galvanometers. By designing a combined tooling that can simultaneously polish multiple RB-SiC galvanometers, and combining uniform pressure loading technology and ultra-smooth flat polishing process, high-efficiency, high-precision, and high-consistency batch polishing of RB-SiC galvanometers can be achieved.

[0012] Compared with the prior art, the present invention has achieved significant progress in the following aspects:

[0013] 1. Existing single-piece CCOS polishing technology uses single-piece clamping and CNC small tool polishing, which can achieve high surface accuracy but is inefficient. This invention uses combined tooling to achieve batch polishing simultaneously, greatly improving production efficiency.

[0014] 2. Traditional mechanical clamping fixtures use direct clamping methods such as pressure plates and positioning baffles, which can generate clamping stress. This invention uses a non-clamping fixing method with nested groove positioning and gravity pressure blocks, avoiding the influence of clamping stress on the surface shape of the ultrathin RB-SiC galvanometer.

[0015] 3. Existing surface modification and polishing methods involve depositing a densification layer on the RB-SiC galvanometer surface before polishing, which is a complex and costly process. This invention directly performs ultra-smooth flat polishing on the RB-SiC galvanometer substrate, using optimized abrasives and process parameters, eliminating the need for an intermediate modification layer.

[0016] 4. While existing ion beam polishing methods can achieve extremely high surface accuracy, the equipment is expensive, inefficient, and unsuitable for mass production. This invention employs a traditional flat polishing process, which has low equipment costs and is suitable for mass production.

[0017] 5. Existing single-sided constant pressure polishing methods mostly use a whole counterweight to apply pressure, which cannot achieve independent pressure control for each workpiece. This invention achieves zoned pressure compensation in batch polishing through an independent pressure block design.

[0018] The technical solution adopted by this invention to solve the technical problem is as follows:

[0019] This invention provides a batch, high-efficiency, high-precision surface polishing method for RB-SiC galvanometers, comprising the following steps:

[0020] (1) Prepare the assembled tooling;

[0021] The combined tooling includes a flat substrate and pressure blocks of different masses. The polished surface of the flat substrate is machined with nested grooves for accommodating RB-SiC galvanometers. The loading surface of the flat substrate has a circular hole corresponding to the center position of each nested groove. The circular hole extends to the bottom of the nested groove. A pressure block is placed independently in each circular hole to apply polishing pressure to the RB-SiC galvanometer in the nested groove.

[0022] (2) Place multiple RB-SiC galvanometers into the nested groove one by one, so that the back of the RB-SiC galvanometer contacts the bottom of the nested groove. Place a selected mass of pressure block into the corresponding circular hole of the RB-SiC galvanometer. The pressure block applies pressure to the RB-SiC galvanometer by its own weight.

[0023] (3) The combined working device containing RB-SiC galvanometer and pressure block is used on a polishing machine for batch ultra-smooth flat polishing.

[0024] Furthermore, the flat substrate is made of chromium zirconium copper or oxygen-free copper, and the flat substrate is a circular plate with a diameter of 300~500mm or a rectangular plate of the corresponding size. The flatness of the upper and lower surfaces of the flat substrate is better than 0.002mm.

[0025] Furthermore, multiple nested grooves 2 are evenly distributed on the polished surface of the flat substrate. The shape of the nested grooves 2 is consistent with the outer contour of the RB-SiC galvanometer. The inner diameter of the nested grooves 2 is 0.02~0.05mm larger than the outer diameter of the RB-SiC galvanometer. The depth of the nested grooves 2 is 1 / 2~2 / 3 of the thickness of the RB-SiC galvanometer.

[0026] Furthermore, the pressure block is made of indium steel with a low coefficient of thermal expansion. The pressure block is a cylinder with a diameter of 4.8 mm and a height of 10-20 mm. The pressure block is clearance-fitted with the circular hole on the loading surface of the flat substrate.

[0027] Furthermore, the weight of the compressed block ranges from 5g to 50g, with a grading accuracy of ±0.5g.

[0028] Furthermore, the ultra-smooth polishing process employs a multi-stage process, including:

[0029] Rough polishing stage: abrasive particle size 80~100nm, polishing pressure 200~300g / cm 2 ;

[0030] Fine polishing stage: abrasive particle size 50~80nm, polishing pressure 100~200g / cm2 ;

[0031] Ultra-fine polishing stage: abrasive particle size 30~50nm, polishing pressure 50~100g / cm 2 .

[0032] Furthermore, the polishing equipment for the ultra-smooth flat polishing process adopts a high-precision flat polishing machine, the polishing pad adopts a polyurethane polishing pad, the abrasive adopts single crystal diamond micro powder or colloidal silica, and the dispersion medium is a water-based liquid containing 80nm single crystal diamond micro powder, a polishing liquid containing diamond micro powder, or a polishing liquid containing colloidal silica.

[0033] Furthermore, the abrasive has a pH of 9-11, a particle size of 30-100 nm, and a mass fraction of 5%-15%.

[0034] Furthermore, by adjusting the quality of the pressure blocks corresponding to different RB-SiC galvanometers, partition pressure compensation is achieved during the batch polishing process, correcting the surface shape error of individual RB-SiC galvanometers.

[0035] Furthermore, after polishing, the RB-SiC galvanometer is ultrasonically cleaned in ultrapure water; the surface shape accuracy is checked using an interferometer, with a PV value better than 1 / 10λ; the surface roughness is checked using an atomic force microscope, with an RMS value less than 0.2nm; and the weight consistency of the RB-SiC galvanometer is checked using a high-precision balance, with a batch deviation ≤ ±0.05g.

[0036] The beneficial effects of this invention are:

[0037] 1. High-efficiency mass production: This invention uses combined tooling, which can polish dozens to hundreds of RB-SiC galvanometers at the same time. Compared with the single-piece processing mode, the production efficiency is increased by 10 to 50 times, and the unit manufacturing cost is significantly reduced.

[0038] 2. High surface accuracy: Using the method of this invention, the surface accuracy PV of the RB-SiC galvanometer can be better than 1 / 10λ (λ=632.8nm), and the surface roughness RMS is less than 0.2nm, reaching the international advanced level and meeting the optical performance requirements of high-end laser RB-SiC galvanometers.

[0039] 3. No clamping stress distortion: The present invention adopts non-clamping fixation, and the RB-SiC galvanometer is not subject to lateral clamping force during polishing, eliminating surface springback after unclamping and ensuring good shape preservation.

[0040] 4. Independent pressure control: Through the independent pressure block design, this invention can apply differentiated polishing pressure to each RB-SiC galvanometer, thereby achieving surface consistency control and local error correction in mass production.

[0041] 5. Good weight consistency: Multiple RB-SiC galvanometers are polished synchronously under the same conditions. The thickness removal of this invention has good consistency, and the weight deviation of batch products can be controlled within ±0.05g, which ensures the consistency of dynamic performance of RB-SiC galvanometer products.

[0042] 6. Strong equipment compatibility: The combined tooling designed in this invention can be adapted to conventional single-sided or double-sided polishing machines, eliminating the need to purchase expensive special equipment and possessing good industrial promotion value.

[0043] 7. Simplified process flow: Compared with surface modification polishing or ion beam polishing, the present invention does not require an intermediate modification layer or vacuum equipment, and the process flow is simple, low-cost and short-cycle. Attached Figure Description

[0044] Figure 1 The flowchart illustrates a batch, high-efficiency, and high-precision surface polishing method for RB-SiC galvanometers provided by this invention.

[0045] Figure 2 This is a schematic diagram of the structure of a flat substrate (polished surface).

[0046] Figure 3 This is a statistical distribution diagram of the surface shape accuracy of RB-SiC galvanometers after batch polishing using the efficient and high-precision surface polishing method for RB-SiC galvanometers provided by this invention.

[0047] In the figure, there is a flat substrate 1 and a nested groove 2. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the accompanying drawings.

[0049] This invention provides a batch high-efficiency and high-precision surface polishing method using RB-SiC galvanometers. Its core lies in constructing a batch polishing process chain of "batch clamping with combined tooling → uniform pressure loading → ultra-smooth surface polishing." The innovatively designed combined tooling employs an embedded RB-SiC galvanometer fixing structure and an independent back-side pressure loading mechanism, solving the three core problems in batch polishing: clamping stress, pressure uniformity, and surface consistency.

[0050] The present invention provides a batch high-efficiency and high-precision surface polishing method for RB-SiC galvanometers, the specific implementation process of which is as follows:

[0051] Step 1: Design and fabrication of the assembly tooling;

[0052] S101: Design of the base of the combined tooling;

[0053] Substrate material: Copper with high thermal conductivity and high flatness retention is selected, such as chromium zirconium copper or oxygen-free copper, and is made into a flat substrate 1 by precision machining.

[0054] Substrate size: Designed according to the worktable of the polishing equipment and batch requirements, the flat substrate 1 is usually set as a circular plate with a diameter of 300~500mm or a rectangular plate of the corresponding size.

[0055] Flatness requirement: The flatness of the upper and lower surfaces of the flat substrate 1 is better than 0.002mm to ensure uniform pressure transmission during the polishing process.

[0056] S102: RB-SiC galvanometer nesting surface design;

[0057] like Figure 2 As shown, a nested groove 2 for accommodating the RB-SiC galvanometer is machined on one side (polished surface) of the flat substrate 1 (circular plate).

[0058] Preferably, multiple nested grooves 2 are evenly distributed on the polished surface of the flat substrate 1, which can realize batch clamping.

[0059] Preferably, the shape of the nested groove 2 is consistent with the outer contour of the RB-SiC galvanometer, such as circular or elliptical.

[0060] Preferably, the inner diameter of the nested groove 2 is 0.02~0.05mm larger than the outer diameter of the RB-SiC galvanometer, which facilitates the insertion and removal of the RB-SiC galvanometer.

[0061] Preferably, the depth of the nested groove 2 is 1 / 2 to 2 / 3 of the thickness of the RB-SiC galvanometer, which allows a portion of the RB-SiC galvanometer to be embedded in the nested groove 2 for lateral positioning.

[0062] S103: Pressure loading structural design;

[0063] On the other side (loading surface) of the flat substrate 1, a circular hole with a diameter of 5 mm is made at the center of each nested groove 2. The circular hole must extend to the bottom of the nested groove 2 to form a pressure channel. At the same time, a pressure block can be independently placed in each circular hole to apply polishing pressure to the RB-SiC galvanometer within the nested groove 2.

[0064] Step 2: Briquetting design and material selection;

[0065] S201: Briquetting material;

[0066] Invar steel (typically grade 4J36), with a low coefficient of thermal expansion, was selected as the briquette material. The linear expansion coefficient of invar steel is approximately 1.2 × 10⁻⁻⁻⁶. 6 / K) and silicon carbide (approximately 2.5 × 10⁻ 6 / K) and copper (approximately 16.8 × 10⁻ 6The / K) varies considerably, but its excellent dimensional stability ensures that pressure remains stable under temperature fluctuations in the polishing environment.

[0067] S202: Briquetting specifications;

[0068] The pressure block is a cylinder with a diameter of 4.8 mm and a height of 10~20 mm, which is clearance-fitted with the circular hole on the loading surface of the flat substrate 1.

[0069] S203: Briquetting quality grading;

[0070] A series of indium steel blocks of different quality grades (mass range 5g~50g, grading accuracy ±0.5g) were prepared for applying different polishing pressures.

[0071] Step 3: Batch clamping and pressure loading of RB-SiC galvanometers;

[0072] S301: Placement of RB-SiC galvanometer;

[0073] After grinding or coarse polishing, the RB-SiC galvanometers are placed one by one into the nested groove 2, ensuring that the back of the RB-SiC galvanometer is in good contact with the bottom of the nested groove 2.

[0074] S302: Block loading;

[0075] According to the polishing process requirements, a pressure block of a selected mass is placed in the corresponding circular hole of the RB-SiC galvanometer. The pressure block applies pressure to the RB-SiC galvanometer using its own weight.

[0076] S303: Pressure homogenization;

[0077] The assembly of the RB-SiC galvanometer and the pressure block is placed on the worktable of the polishing equipment. Under the action of the polishing pad, the pressure on each RB-SiC galvanometer is determined by the mass of the pressure block and the elastic deformation of the polishing pad.

[0078] S304: Non-contact fixing;

[0079] This invention does not use traditional clamps to hold the RB-SiC galvanometer laterally. The RB-SiC galvanometer is positioned solely by the nested groove 2 and fixed by its own weight, thus avoiding surface distortion caused by clamping stress.

[0080] Step 4: Ultra-smooth surface polishing process;

[0081] S401: Polishing equipment;

[0082] High-precision flat polishing machines are used, such as double-sided polishing machines or single-sided constant pressure polishing machines.

[0083] S402: Polishing pad selection;

[0084] Use polyurethane polishing pads, such as LP-66 and Politex, which are high-density polishing pads with a Shore hardness of A50~70.

[0085] S403: Polishing fluid preparation;

[0086] Abrasive: Single-crystal diamond powder or colloidal silicon dioxide are selected.

[0087] Dispersion medium: Use deionized water or special polishing fluid (such as water-based fluid containing 80nm single crystal diamond powder, polishing fluid containing 50nm diamond powder, or polishing fluid containing 30nm colloidal silica).

[0088] Abrasive pH: Adjust the pH to 9-11 to improve the dispersion stability of the dispersion medium.

[0089] Abrasive particle size: The preferred particle size is 30~100nm.

[0090] Abrasive concentration: preferably 5%~15% by mass.

[0091] S404: Process parameter optimization;

[0092] Polishing pressure: Adjust the pressure to 50~300g / cm by changing the pressure block of different quality. 2 Within the range.

[0093] Polishing speed: preferably 10~60 rpm.

[0094] Polishing fluid flow rate: preferably 50~200mL / min.

[0095] Polishing time: Determined based on initial surface quality and target requirements, typically 30~180 min.

[0096] S405: Multi-stage polishing strategy;

[0097] Coarse polishing stage: large-diameter abrasive (80~100nm) + large-mass compacted blocks (200~300g / cm³) 2 It can quickly remove the abrasion damage layer.

[0098] Fine polishing stage: medium-sized abrasive (50~80nm) + medium pressure (100~200g / cm) 2 This reduces surface roughness.

[0099] Ultra-fine polishing stage: small-diameter abrasive (30~50nm) + light pressure (50~100g / cm) 2 This allows for the creation of ultra-smooth surfaces.

[0100] Step 5: Surface shape accuracy control;

[0101] S501: Zone pressure compensation;

[0102] For individual RB-SiC galvanometers with large surface shape errors, the surface shape can be corrected by adjusting the local pressure by changing the mass of the corresponding pressure block.

[0103] S502: Tooling flip-polishing;

[0104] After polishing one side, the RB-SiC galvanometer can be flipped over (with the mirror facing down in contact with the polishing pad), and pressure is applied to the back by the pressure block to perform final fine polishing on the mirror surface.

[0105] S503: Polishing endpoint determination;

[0106] The final thickness and weight consistency of the RB-SiC galvanometer are controlled by using online thickness monitoring or timed sampling inspection.

[0107] Step Six: Cleaning and Testing;

[0108] S601: After polishing, the RB-SiC galvanometer is ultrasonically cleaned in ultrapure water to remove any remaining polishing solution from the surface.

[0109] S602: Use an interferometer (such as Zygo) to detect the surface shape accuracy (PV value), which is required to be better than 1 / 10λ (λ=632.8nm).

[0110] S603: Surface roughness is measured using atomic force microscopy (AFM), and the required RMS is less than 0.2 nm.

[0111] S604: Use a high-precision balance to weigh and check the weight consistency of the RB-SiC galvanometer, requiring a batch deviation of ≤±0.05g.

[0112] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0113] Example 1

[0114] This embodiment uses the batch polishing of a batch of circular RB-SiC galvanometers with a diameter of 20mm as an example to illustrate the specific implementation process of the present invention.

[0115] (1) Design and fabrication of modular tooling;

[0116] A circular chromium-zirconium-copper plate with a diameter of 400 mm and a thickness of 30 mm was prepared as a flat substrate 1. The flat substrate 1 was ground on both sides to a flatness of 0.002 mm. Twenty-one circular nested grooves 2 were machined on the polished surface of the flat substrate 1. The diameter of the nested grooves 2 was 20.05 mm, which was 0.05 mm larger than the diameter of the RB-SiC galvanometer, and the depth of the nested grooves 2 was 1.0 mm. Twenty-one circular holes with a diameter of 5 mm and a depth of 29 mm (penetrating to the bottom of the nested grooves 2) were machined on the loading surface of the flat substrate 1 at the positions corresponding to the nested grooves 2.

[0117] (2) Design and material selection of briquettes;

[0118] Twenty-one cylindrical pressure blocks of 4J36 indium steel were prepared, with a diameter of 4.8 mm and a height of 12 mm. The weights were divided into three grades: 15 g, 20 g, and 25 g, with an accuracy of ±0.5 g.

[0119] (3) Batch clamping and pressure loading of RB-SiC galvanometers;

[0120] Twenty-one RB-SiC galvanometers (2.0 mm thick), ground to a surface roughness Ra of approximately 50 nm, were placed in nested groove 2 with the mirror surfaces facing upwards. The weight of the pressure block was selected according to the polishing process stage; a 25 g pressure block was used for the rough polishing stage, corresponding to a pressure of approximately 140 g / cm. 2 .

[0121] (4) Ultra-smooth polishing process;

[0122] Rough polishing stage: A single-sided constant pressure polishing machine was used; the polishing pad was an LP-66 polyurethane polishing pad; the dispersion medium was an aqueous solution containing 80nm single-crystal diamond micropowder; the abrasive concentration was 10%, pH=10.5; the briquette size was 25g; and the polishing pressure was 140g / cm. 2 Polishing speed 30 rpm, polishing fluid flow rate 100 mL / min, polishing time 60 minutes.

[0123] Fine polishing stage: A single-sided constant pressure polishing machine is used; the polishing pad is an LP-66 polyurethane polishing pad; the dispersion medium is replaced with a polishing slurry containing 50nm diamond micropowder; the pressure block is replaced with a 20g block; the polishing pressure is 110g / cm. 2 Polishing time is 45 minutes, with other parameters remaining unchanged.

[0124] Ultra-fine polishing stage: A single-sided constant pressure polishing machine is used; the polishing pad is an LP-66 polyurethane polishing pad; the dispersion medium is replaced with a polishing slurry containing 30nm colloidal silica; the pressure block is replaced with a 15g block; the polishing pressure is 80g / cm. 2 Polishing time is 30 minutes, and other parameters remain unchanged.

[0125] (5) Surface shape accuracy control;

[0126] S501: Zone pressure compensation;

[0127] For individual RB-SiC galvanometers with large surface shape errors, the surface shape can be corrected by adjusting the local pressure by changing the mass of the corresponding pressure block.

[0128] S502: Tooling flip-polishing;

[0129] After polishing one side, the RB-SiC galvanometer can be flipped over (with the mirror facing down in contact with the polishing pad), and pressure is applied to the back by the pressure block to perform final fine polishing on the mirror surface.

[0130] S503: Polishing endpoint determination;

[0131] The final thickness and weight consistency of the RB-SiC galvanometer are controlled by using online thickness monitoring or timed sampling inspection.

[0132] (6) Cleaning and testing;

[0133] After polishing, the RB-SiC galvanometers were ultrasonically cleaned three times for 5 minutes each in ultrapure water to remove any remaining polishing solution. The surface shape accuracy (PV value) was measured using a Zygo interferometer, with an average PV of 0.085λ (λ = 632.8 nm). The surface roughness was measured using an AFM atomic force microscope, with an average RMS of 0.18 nm. The weight of the 21 RB-SiC galvanometers ranged from 3.95 g to 4.03 g, with a deviation of ±0.04 g, meeting the performance requirements.

[0134] Example 2

[0135] This embodiment takes the application of different pressure compensation to correct surface shape errors as an example.

[0136] During batch polishing, if a localized surface shape error (such as edge warping) occurs in a certain RB-SiC galvanometer, it can be adjusted by replacing the pressure block at the corresponding location. For example, if the central area of ​​the RB-SiC galvanometer is concave, the mass of the pressure block at that location can be increased from 20g to 30g in subsequent polishing stages. This increases the pressure on the edge of the RB-SiC galvanometer, causing more material to be removed from the edge and thus improving the surface shape. Experiments show that through 2-3 pressure compensation adjustments, the PV value of the RB-SiC galvanometer surface shape can be improved from 0.15λ to below 0.08λ. Figure 3 As shown.

[0137] This invention discloses a batch, high-efficiency, and high-precision surface polishing method for RB-SiC galvanometers. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The product of this invention has been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the product described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

Claims

1. A method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers, characterized in that, Includes the following steps: (1) Prepare the assembled tooling; The combined tooling includes a flat substrate and pressure blocks of different masses. The polished surface of the flat substrate is machined with nested grooves for accommodating RB-SiC galvanometers. The loading surface of the flat substrate has a circular hole corresponding to the center position of each nested groove. The circular hole extends to the bottom of the nested groove. A pressure block is placed independently in each circular hole to apply polishing pressure to the RB-SiC galvanometer in the nested groove. (2) Place multiple RB-SiC galvanometers into the nested groove one by one, so that the back of the RB-SiC galvanometer contacts the bottom of the nested groove. Place a selected mass of pressure block into the corresponding circular hole of the RB-SiC galvanometer. The pressure block applies pressure to the RB-SiC galvanometer by its own weight. (3) The combined working device containing RB-SiC galvanometer and pressure block is used on a polishing machine for batch ultra-smooth flat polishing.

2. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, The flat substrate is made of chromium zirconium copper or oxygen-free copper. The flat substrate is a circular plate with a diameter of 300-500 mm or a rectangular plate of the corresponding size. The flatness of the upper and lower surfaces of the flat substrate is better than 0.002 mm.

3. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, Multiple nested grooves 2 are evenly distributed on the polished surface of the flat substrate. The shape of the nested grooves 2 is consistent with the outer contour of the RB-SiC galvanometer. The inner diameter of the nested grooves 2 is 0.02~0.05mm larger than the outer diameter of the RB-SiC galvanometer. The depth of the nested grooves 2 is 1 / 2~2 / 3 of the thickness of the RB-SiC galvanometer.

4. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, The pressure block is made of indium steel with a low coefficient of thermal expansion. The pressure block is a cylinder with a diameter of 4.8 mm and a height of 10-20 mm. The pressure block is clearance-fitted with the circular hole on the loading surface of the flat substrate.

5. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, The weight range of the compressed blocks is 5g to 50g, and the grading accuracy is ±0.5g.

6. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, The ultra-smooth polishing process employs a multi-stage process, including: Rough polishing stage: abrasive particle size 80~100nm, polishing pressure 200~300g / cm 2 ; Fine polishing stage: abrasive particle size 50~80nm, polishing pressure 100~200g / cm 2 ; Ultra-fine polishing stage: abrasive particle size 30~50nm, polishing pressure 50~100g / cm 2 .

7. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, The polishing equipment for the ultra-smooth flat polishing process is a high-precision flat polishing machine. The polishing pad is a polyurethane polishing pad. The abrasive is single-crystal diamond micro powder or colloidal silica. The dispersion medium is a water-based liquid containing 80nm single-crystal diamond micro powder, a polishing liquid containing diamond micro powder, or a polishing liquid containing colloidal silica.

8. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 7, characterized in that, The abrasive has a pH of 9-11, a particle size of 30-100 nm, and a mass fraction of 5%-15%.

9. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, By adjusting the quality of the pressure blocks corresponding to different RB-SiC galvanometers, partition pressure compensation is achieved during the batch polishing process, correcting the surface shape error of individual RB-SiC galvanometers.

10. The method for batch, high-efficiency, and high-precision surface polishing of RB-SiC galvanometers according to claim 1, characterized in that, After polishing, the RB-SiC galvanometer is ultrasonically cleaned in ultrapure water; the surface shape accuracy is checked using an interferometer, and the PV value is better than 1 / 10λ; the surface roughness is checked using an atomic force microscope, and the RMS is less than 0.2nm; the weight consistency of the RB-SiC galvanometer is checked using a high-precision balance, and the batch deviation is ≤±0.05g.

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