Fine polishing method applied to diamond substrate

Abstract

The invention relates to the technical field of polishing, and discloses a fine polishing method applied to diamond substrates, which comprises the following steps: providing a plurality of diamond substrates with preset sizes and a bearing disc, and adhering and fixing the diamond substrates on the bearing disc; providing a polishing pad, and abutting the diamond substrate against the polishing pad; a polishing solution is supplied to the diamond substrate in a circulation mode or a drop mode; the bearing disc is controlled to rotate at a first preset rotating speed, the polishing pad is controlled to rotate at a second preset rotating speed, and the polishing pad is controlled to apply pressure to the diamond substrate at preset pressure for fine polishing; according to the invention, the treatment capacity in unit time is obviously improved, and the production cost can be effectively reduced; the bearing disc and the polishing pad are controlled to rotate together, and pressure is applied to the diamond substrates through the polishing pad, so that force distribution on the multiple diamond substrates in the polishing process is more uniform, the phenomenon of uneven polishing is effectively reduced, and therefore the surface precision of the surfaces of the diamond substrates is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of polishing, and in particular to a fine polishing method applied to a diamond substrate. Background Art

[0002] Diamond is widely used in optics, electronics and other fields due to its excellent hardness, thermal conductivity, wear resistance and other properties. In particular, diamond substrates have gradually become an indispensable material in the manufacture of high-end precision devices and high-power semiconductor devices. However, due to the extremely high hardness and brittleness of diamond itself, its surface processing, especially the precision polishing process, often faces many challenges, which directly affects the final performance of the device. Therefore, the development of an efficient and high-quality diamond substrate polishing method is of great industry significance.

[0003] At present, the single-chip processing method is generally used in the fine polishing process of diamond substrates. However, this method still has many shortcomings in terms of processing efficiency and surface profile accuracy. In the single-chip processing of diamond substrates, due to uneven force and the limitations of polishing tools, uneven polishing often occurs, which in turn leads to poor surface profile accuracy of diamond substrates, directly affecting the quality and performance of subsequent devices, and bringing obvious adverse effects in the field of high-precision optical and electronic components.

[0004] Therefore, it is necessary to provide a precision polishing method for diamond substrates to solve the problem of poor surface profile accuracy during the precision polishing process of the diamond substrates. Summary of the invention

[0005] The main purpose of the present invention is to provide a precision polishing method for diamond substrates, aiming to solve the technical problems mentioned in the above background technology.

[0006] The present invention adopts the following technical solutions: A fine polishing method for a diamond substrate, comprising: Providing a plurality of diamond substrates and carrier plates of preset sizes, and gluing and fixing the diamond substrates on the carrier plates; Providing a polishing pad, and bringing a diamond substrate fixed on the carrier plate into contact with the polishing pad; supplying polishing liquid to the diamond substrate in a circulation mode or a drip mode; The carrier plate is controlled to rotate at a first preset rotation speed, the polishing pad is controlled to rotate at a second preset rotation speed, and the polishing pad is controlled to apply pressure to the diamond substrate for fine polishing at a preset pressure, so that the diamond substrate forms a preset fine polishing surface.

[0007] Furthermore, the step of gluing and fixing the diamond substrate on the carrier plate specifically includes: Selecting a plurality of diamond substrates of preset sizes, and pre-treating the diamond substrates in a vacuum environment; Evenly coating a preset adhesive on the workbench of the carrier plate, and bonding the diamond substrate to the workbench of the carrier plate; Performing a vacuum treatment on the bonding interface between the diamond substrate and the carrier plate to remove bubbles in the bonding interface so that the diamond substrate and the carrier plate are closely attached; Applying a constant pressing force to the bonded diamond substrate; The preset adhesive is heated at a preset heating temperature to solidify the preset adhesive.

[0008] Furthermore, the step of pre-treating the diamond substrate in a vacuum environment specifically includes: Placing the diamond substrate in a vacuum chamber, and reducing the pressure of the vacuum chamber to a preset vacuum degree to remove gas from the surface of the diamond substrate; Performing a plasma cleaning process on the diamond substrate in the vacuum chamber to remove organic matter and impurity particles on the surface of the diamond substrate; The diamond substrate after the plasma cleaning treatment is baked at a preset baking temperature to remove trace moisture and volatile substances on the surface of the diamond substrate.

[0009] Furthermore, the step of uniformly coating a preset adhesive on the workbench of the carrier plate and bonding the diamond substrate to the workbench of the carrier plate specifically includes: Controlling the carrier plate to rotate at a speed of 10 to 30 revolutions per minute; Adhesive wax is used as the preset adhesive, and the adhesive wax having a thickness of 10 microns to 50 microns is evenly coated on the workbench of the carrier plate; After coating is completed, the carrier plate is controlled to stop rotating, so that the adhesive wax is self-leveled on the workbench of the carrier plate.

[0010] Furthermore, the step of heating the preset adhesive at a preset heating temperature to solidify the preset adhesive specifically includes: Placing the diamond substrate in a heating device, and setting a preset heating temperature for the heating device according to the curing characteristics of the preset adhesive; Starting the heating device and gradually raising the temperature to the preset heating temperature in a multi-stage heating manner; The preset adhesive is subjected to temperature detection, and after the preset adhesive reaches a preset heating temperature, the preset adhesive is heated for a preset time to complete the curing of the preset adhesive.

[0011] Further, the step of supplying polishing liquid to the diamond substrate in a circulation mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; Using a liquid supply pump to transport the polishing liquid from the liquid storage tank to the surface of the polishing pad, so that the polishing liquid evenly covers the diamond substrate at a flow rate of 5-15 liters per minute; Building a filter and a reflux pipeline, wherein the reflux pipeline is connected to the liquid storage tank, and the filter is arranged in the reflux pipeline, so that the polishing liquid can be circulated; The step of supplying polishing liquid to the diamond substrate in a drip mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; The polishing liquid is dripped from the liquid storage tank to the polishing pad at a flow rate of 150-300 ml per minute using a metering pump.

[0012] Further, the step of controlling the carrier plate to rotate at a first preset speed, controlling the polishing pad to rotate at a second preset speed, and controlling the polishing pad to perform pressure polishing on the diamond substrate at a preset pressure specifically includes: Setting a first preset rotation speed of the carrier plate and a second preset rotation speed and a preset pressure value of the polishing pad, driving the carrier plate to rotate at the first preset rotation speed by a first motor, driving the polishing pad to rotate at the second preset rotation speed by a second motor, and driving the polishing pad to perform fine polishing on the diamond substrate at a preset pressure value by a linear motor provided with a pressure sensor; Real-time detection of the flatness and consistency of the surface of the diamond substrate, and judging the fine polishing effect of the diamond substrate based on the detection results; The first preset rotation speed, the second preset rotation speed and the preset pressure value are adjusted according to the fine polishing effect, so that the diamond substrate forms a preset fine polishing surface shape.

[0013] Furthermore, the step of detecting the flatness and consistency of the surface of the diamond substrate in real time and judging the fine polishing effect of the diamond substrate based on the detection result specifically includes: Scanning the surface of the diamond substrate in real time and collecting a surface image of the diamond substrate; Preprocessing the surface image for noise elimination and definition enhancement, constructing a three-dimensional point cloud image of the surface of the diamond substrate, and extracting texture features and topographic features of the diamond substrate; Calculating the roughness and uniformity in the randomly selected area according to the texture characteristics and topographic characteristics; Comparing the calculated result with the preset roughness and uniformity to determine whether the diamond substrate reaches the preset fine polishing surface; If the diamond substrate does not reach the preset fine polishing surface, the first preset speed, the second preset speed and the preset pressure value are adjusted to continue fine polishing; if the diamond substrate reaches the preset fine polishing surface, the first motor, the second motor and the linear motor are stopped to complete the fine polishing process.

[0014] Furthermore, the number of the diamond substrates is 3, and the preset size of the diamond substrate is 2 inches or 4 inches.

[0015] Furthermore, the polishing pad is a damping cloth polishing pad, the first preset speed is 51-57 revolutions per minute, the second preset speed is 17-19 revolutions per minute, and the ratio of the first preset speed to the second preset speed is three to one, and the preset pressure value is 200-400 grams per square centimeter.

[0016] Beneficial effects: In a fine polishing method applied to a diamond substrate of the present invention, by processing multiple diamond substrates on a carrier plate at the same time, the processing efficiency is greatly improved, the processing volume per unit time is significantly increased, and the production cost can be effectively reduced; the polishing liquid is supplied to the diamond substrate in a circulation mode or a drip mode to ensure the uniform distribution and continuous supply of the polishing liquid during the polishing process, thereby ensuring efficient polishing operation, reducing the idling of the polishing pad during the polishing process, and improving the overall processing efficiency. By controlling the carrier plate and the polishing pad to rotate together and applying pressure to the diamond substrate through the polishing pad, the force distribution on the multiple diamond substrates during the polishing process is more uniform, effectively reducing the uneven polishing phenomenon, thereby significantly improving the surface profile accuracy of the diamond substrate, and the balanced polishing pressure enables each substrate to obtain a consistent polishing effect, thereby improving the quality and performance of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is one of the flow diagrams of a precision polishing method for a diamond substrate according to the present invention; Figure 2 This is the second schematic flow diagram of a precision polishing method applied to a diamond substrate of the present invention.

[0018] Figure 3 This is the third flow chart of a precision polishing method applied to a diamond substrate of the present invention.

[0019] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] Reference Figure 1 The present invention proposes a precision polishing method for a diamond substrate, comprising: S1: providing a plurality of diamond substrates and carrier plates of preset sizes, and gluing and fixing the diamond substrates on the carrier plates; In step S1, three 2-inch or 4-inch diamond substrates are preferably used and glued to a carrier plate by a wax gluing process. The carrier plate may be an alumina ceramic plate, a stainless steel plate, or a zirconia ceramic and adsorption pad.

[0025] S2: providing a polishing pad, and bringing the diamond substrate fixed on the carrier plate into contact with the polishing pad; In step S2, the polishing pad may be a black damping polishing pad, a white damping polishing pad, or other types of polishing pads, such as a polyurethane polishing pad. The material and type of the polishing pad to be selected depends on the surface characteristics of the diamond substrate and the required polishing effect. The black damping polishing pad generally has good water absorption and polishing properties and is suitable for fine polishing; while the white damping polishing pad can provide a more uniform polishing effect and is suitable for large-area diamond substrates.

[0026] S3: supplying polishing liquid to the diamond substrate in a circulation mode or a drip mode; In step S3, the supply method of the polishing liquid has a significant impact on the polishing effect. In the circulation mode, the polishing liquid forms a continuous flow between the polishing pad and the diamond substrate, which helps to quickly remove the debris generated by polishing while keeping the polishing surface clean and cool. This mode is suitable for occasions where efficient material removal is required. The drip mode is to drip the polishing liquid into the polishing area at a regular or quantitative time during the polishing process. This method can more accurately control the amount of polishing liquid used and is suitable for situations where high polishing accuracy is required. According to the material properties and polishing requirements of the diamond substrate, selecting a suitable supply mode can effectively improve the polishing quality and efficiency.

[0027] S4: Control the carrier plate to rotate at a first preset rotation speed, control the polishing pad to rotate at a second preset rotation speed, and control the polishing pad to apply pressure to the diamond substrate for fine polishing at a preset pressure, so that the diamond substrate forms a preset fine polishing surface.

[0028] In step S4, precise control of rotation speed and pressure is the key to achieve high-quality polishing. The rotation speed of the carrier plate determines the relative speed at which the substrate surface contacts the polishing pad, while the rotation speed of the polishing pad affects the distribution and flow of the polishing liquid on the substrate surface. By optimizing these two parameters, scratches and uneven polishing can be effectively avoided, ensuring the polishing quality of the entire substrate surface. The application of a preset pressure ensures that the appropriate contact force is maintained between the polishing pad and the diamond substrate, which is essential for obtaining a smooth and damage-free fine polishing surface. By comprehensively considering the substrate material properties, the polishing pad type and the polishing liquid properties, the optimal rotation speed and pressure parameters can be set to achieve an ideal polishing effect.

[0029] In summary, by processing multiple diamond substrates on the carrier plate at the same time, the processing efficiency is greatly improved, the processing volume per unit time is significantly increased, and the production cost can be effectively reduced; the polishing liquid is supplied to the diamond substrate in a circulation mode or a drip mode to ensure the uniform distribution and continuous supply of the polishing liquid during the polishing process, thereby ensuring efficient polishing operations, reducing the idling of the polishing pad during the polishing process, and improving the overall processing efficiency. By controlling the carrier plate and the polishing pad to rotate together and applying pressure to the diamond substrate through the polishing pad, the force distribution on multiple diamond substrates during the polishing process is more uniform, effectively reducing the uneven polishing phenomenon, thereby significantly improving the surface profile accuracy of the diamond substrate, and the balanced polishing pressure enables each substrate to obtain a consistent polishing effect, thereby improving the quality and performance of the final product.

[0030] refer to Figure 2 In one embodiment, the step of gluing and fixing the diamond substrate on the carrier plate specifically includes: S11: selecting a plurality of diamond substrates of preset sizes, and pre-treating the diamond substrates in a vacuum environment; In step S11, the process of selecting diamond substrates of preset size requires special attention to the uniformity and consistency of the substrates to ensure the efficiency and quality of the subsequent polishing process. To achieve this goal, an automated screening system can be used, which can accurately measure and classify diamond substrates according to preset size standards. In this way, it can be ensured that each substrate meets the specific size requirements, thereby reducing the problem of uneven polishing caused by size differences.

[0031] S12: evenly coating a preset adhesive on the workbench of the carrier plate, and bonding the diamond substrate to the workbench of the carrier plate; In step S12, uniformly coating the preset adhesive is one of the key steps. To achieve this, a precision coating device can be used, which can ensure uniform distribution of the adhesive on the carrier plate workbench. In addition, environmental control during the coating process is also very important, and it needs to be carried out under dust-free and constant temperature and humidity conditions to avoid uneven drying or solidification of the adhesive during the coating process, which affects the bonding effect.

[0032] S13: performing a vacuum treatment on the bonding interface between the diamond substrate and the carrier plate to remove bubbles in the bonding interface so that the diamond substrate and the carrier plate are closely attached; In step S13, the vacuum treatment is to ensure that there are no bubbles remaining in the bonding interface, which is crucial to ensure a tight fit between the diamond substrate and the carrier plate. Therefore, a high-efficiency vacuum pump system can be used, and a vacuum degree detection device can be used to ensure that the bonding interface reaches the required vacuum degree. In addition, the vacuum time and vacuum degree control need to be optimized according to the characteristics of the adhesive and the material of the substrate to achieve the best bonding effect.

[0033] S14: applying a constant pressing force to the bonded diamond substrate; In step S14, a constant pressing force is applied to ensure good contact between the diamond substrate and the carrier plate, thereby improving the bonding strength. To this end, a precise pressure control system can be designed, which can apply uniform pressure to the diamond substrate according to a preset pressure value. At the same time, the pressure needs to be applied before the adhesive is cured to avoid a gap between the substrate and the carrier plate due to the shrinkage force generated during the curing process.

[0034] S15: heating the preset adhesive at a preset heating temperature to solidify the preset adhesive.

[0035] In step S15, the heating treatment of the preset adhesive is to accelerate the curing process and improve the bonding strength. Therefore, a heating device with precise temperature control can be used, which can provide a stable heating temperature according to the curing characteristics of the adhesive. In addition, the temperature gradient control during the heating process is also very important. It is necessary to ensure that the temperature of the entire carrier plate workbench is uniform to avoid uneven curing of the adhesive due to excessively high or low local temperatures, which affects the bonding quality.

[0036] refer to Figure 3 In one example, the step S11 of pre-treating the diamond substrate in a vacuum environment specifically includes: S21: placing the diamond substrate in a vacuum chamber, and reducing the pressure of the vacuum chamber to a preset vacuum degree to remove gas on the surface of the diamond substrate; In step S21, the diamond substrate is placed in a vacuum chamber and the pressure is reduced to a preset vacuum degree to ensure that the gas on the substrate surface is completely removed during the subsequent plasma cleaning process, thereby improving the cleaning effect. The vacuum environment can effectively reduce the interference of gas molecules on the plasma cleaning process, ensure that the plasma can act evenly on the surface of the diamond substrate, and achieve the purpose of completely removing organic matter and impurity particles.

[0037] S22: performing a plasma cleaning process on the diamond substrate in the vacuum chamber to remove organic matter and impurity particles on the surface of the diamond substrate; In step S22, plasma cleaning is an effective surface treatment technology that uses active particles in plasma to chemically react with organic matter and impurity particles on the substrate surface to clean the substrate surface. In this step, the type, energy and action time of plasma need to be precisely controlled to ensure the cleaning effect while avoiding damage to the diamond substrate.

[0038] S23: baking the diamond substrate after the plasma cleaning treatment at a preset baking temperature to remove trace moisture and volatile substances on the surface of the diamond substrate.

[0039] In step S23, the purpose of the baking treatment is to further remove residual moisture and volatile substances on the surface of the diamond substrate, which may affect the bonding strength and quality in the subsequent bonding process. The selection of the preset baking temperature needs to take into account the thermal stability of the diamond substrate to avoid deformation or damage to the substrate caused by high temperature. The baking process should ensure uniform temperature to avoid local overheating or overcooling, so as to ensure consistent baking effect on the entire substrate surface.

[0040] In one embodiment, the step of uniformly coating a preset adhesive on the workbench of the carrier plate and bonding the diamond substrate to the workbench of the carrier plate specifically includes: Controlling the carrier plate to rotate at a speed of 10 to 30 revolutions per minute; Adhesive wax is used as the preset adhesive, and the adhesive wax having a thickness of 10 microns to 50 microns is evenly coated on the workbench of the carrier plate; After coating is completed, the carrier plate is controlled to stop rotating, so that the adhesive wax is self-leveled on the workbench of the carrier plate.

[0041] In the above embodiment, during the process of controlling the rotation of the carrier plate, the rotation speed is ensured to be stable to ensure that the adhesive wax is evenly coated on the workbench. Too fast a rotation speed may cause the adhesive wax to splash, while too slow a rotation speed may not achieve the desired coating effect. Therefore, the rotation speed of 10 to 30 revolutions per minute is selected to take into account both the uniformity of coating and the ease of operation.

[0042] Adhesive wax is used as the preset adhesive because it has good adhesive properties and a suitable melting point, and can be easily removed in the subsequent baking process without causing damage to the diamond substrate. The adhesive wax with a thickness of 10 to 50 microns is evenly coated on the workbench to ensure that there is enough bonding area between the diamond substrate and the carrier during the bonding process, while avoiding excessive thickness of the adhesive wax, which leads to long or uneven baking time.

[0043] After coating, the carrier plate is controlled to stop rotating, so that the adhesive wax can be self-leveled on the workbench. This process is to allow the adhesive wax to flow naturally under the action of gravity, filling the tiny unevenness on the surface of the workbench, so as to obtain a flat bonding surface. The time of self-leveling treatment needs to be appropriately adjusted according to the type of adhesive wax and the ambient temperature to ensure the uniformity of the bonding surface.

[0044] Through the above steps, it can be ensured that the diamond substrate and the carrier plate are evenly and firmly bonded, providing stable support for the subsequent fine polishing process, thereby improving the accuracy and efficiency of the fine polishing.

[0045] In one embodiment, the step of heating the preset adhesive at a preset heating temperature to cure the preset adhesive specifically includes: Placing the diamond substrate in a heating device, and setting a preset heating temperature for the heating device according to the curing characteristics of the preset adhesive; Starting the heating device and gradually raising the temperature to the preset heating temperature in a multi-stage heating manner; The preset adhesive is subjected to temperature detection, and after the preset adhesive reaches a preset heating temperature, the preset adhesive is heated for a preset time to complete the curing of the preset adhesive.

[0046] In the above embodiment, the diamond substrate is placed in the heating device, and the preset heating temperature is set for the heating device according to the curing characteristics of the preset adhesive. This process requires precise control to ensure that the adhesive is cured at an appropriate temperature to avoid affecting the bonding effect due to too high or too low temperature. The setting of the preset heating temperature is usually based on the melting point of the adhesive wax and the temperature range of baking removal to ensure that the adhesive wax can be fully melted and easily removed during the baking process without causing damage to the diamond substrate.

[0047] The heating device is started and gradually raised to the preset heating temperature in a multi-stage heating method. The multi-stage heating method helps to avoid thermal stress caused by rapid temperature changes, thereby protecting the diamond substrate from damage. In each stage, the temperature increase and duration need to be precisely controlled according to the type of bonding wax and the material properties of the workbench to ensure uniformity and stability of the entire baking process.

[0048] The preset adhesive is temperature-tested, and after the preset adhesive reaches the preset heating temperature, the preset adhesive is heated for a preset time to complete the curing of the preset adhesive. Temperature detection can be performed in a variety of ways, such as using a thermocouple or an infrared thermometer, to ensure accurate temperature measurement. The preset time is set based on the curing characteristics of the adhesive wax to ensure that the adhesive is completely cured at an appropriate heating time, thereby forming a strong bonding effect.

[0049] Through the above steps, it can be ensured that the diamond substrate and the carrier plate are evenly and firmly bonded, providing stable support for the subsequent fine polishing process, thereby improving the accuracy and efficiency of the fine polishing.

[0050] In one embodiment, the step of supplying polishing liquid to the diamond substrate in a circulation mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; Using a liquid supply pump to transport the polishing liquid from the liquid storage tank to the surface of the polishing pad, so that the polishing liquid evenly covers the diamond substrate at a flow rate of 5-15 liters per minute; Building a filter and a reflux pipeline, wherein the reflux pipeline is connected to the liquid storage tank, and the filter is arranged in the reflux pipeline, so that the polishing liquid can be circulated; The step of supplying polishing liquid to the diamond substrate in a drip mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; The polishing liquid is dripped from the liquid storage tank to the polishing pad at a flow rate of 150-300 ml per minute using a metering pump.

[0051] In the above embodiment, in the circulation mode, the supply of polishing liquid is not limited to uniformly covering the diamond substrate, but also includes continuous wetting and cooling of the polishing pad, and the most preferred circulation flow rate is 10 liters per minute. The polishing pad will generate heat due to friction during the polishing process. Appropriate supply of polishing liquid helps to maintain the temperature of the polishing pad and prevent damage to the substrate caused by overheating. In addition, by setting the filter, impurities and wear particles in the polishing liquid can be effectively removed to ensure the cleanliness of the polishing liquid, thereby improving the polishing quality.

[0052] In the drip mode, the supply of polishing liquid is more precise and controlled. The use of a metering pump ensures that the polishing liquid is dripped onto the polishing pad at a precise flow rate, avoiding waste of polishing liquid and enabling local intensive polishing of different areas of the diamond substrate. This mode is particularly suitable for areas that require fine processing, such as polishing of edges or specific patterns.

[0053] In actual operation, the circulation mode and drip mode can be flexibly switched according to the specific needs and polishing requirements of the diamond substrate. For example, in the early stage of polishing, the circulation mode may be needed to quickly remove surface unevenness; while near the final polishing stage, switch to the drip mode to achieve a finer surface treatment. Through this combination, the best polishing effect can be achieved to ensure that the surface quality of the diamond substrate meets the design requirements.

[0054] In one embodiment, the step of controlling the carrier plate to rotate at a first preset speed, controlling the polishing pad to rotate at a second preset speed, and controlling the polishing pad to perform pressure polishing on the diamond substrate at a preset pressure specifically includes: Setting a first preset rotation speed of the carrier plate and a second preset rotation speed and a preset pressure value of the polishing pad, driving the carrier plate to rotate at the first preset rotation speed by a first motor, driving the polishing pad to rotate at the second preset rotation speed by a second motor, and driving the polishing pad to perform fine polishing on the diamond substrate at a preset pressure value by a linear motor provided with a pressure sensor; Real-time detection of the flatness and consistency of the surface of the diamond substrate, and judging the fine polishing effect of the diamond substrate based on the detection results; The first preset rotation speed, the second preset rotation speed and the preset pressure value are adjusted according to the fine polishing effect, so that the diamond substrate forms a preset fine polishing surface shape.

[0055] In the above embodiment, the first preset rotation speed of the carrier plate and the second preset rotation speed and the preset pressure value of the polishing pad are set. The first motor is responsible for driving the carrier plate to rotate at the first preset rotation speed to ensure that the diamond substrate remains stable during the fine polishing process. The second motor drives the polishing pad to rotate at the second preset rotation speed to ensure that there is an appropriate relative motion speed between the polishing pad and the diamond substrate, thereby achieving efficient material removal.

[0056] The linear motor is equipped with a pressure sensor that can monitor and adjust the pressure applied to the polishing pad in real time to ensure that the diamond substrate is subjected to uniform pressure during the fine polishing process. This precise control of pressure is crucial to forming a high-quality fine polishing surface.

[0057] During the fine polishing process, it is crucial to detect the flatness and consistency of the diamond substrate surface in real time. By using high-precision detection equipment such as optical interferometers or atomic force microscopes, the surface of the diamond substrate can be monitored in real time. The detection results will be fed back to the control system to judge the fine polishing effect.

[0058] According to the detection results, the control system will automatically adjust the first preset speed, the second preset speed and the preset pressure value. If it is detected that the surface flatness of the diamond substrate is insufficient or inconsistent, the control system will adjust the speed and pressure parameters accordingly to optimize the fine polishing effect. This process may require multiple iterations until the surface of the diamond substrate reaches the desired fine polishing surface.

[0059] Through precise control and real-time feedback of the above steps, high-quality polishing of the diamond substrate can be achieved, ensuring that its surface flatness and consistency meet the requirements of high-end applications.

[0060] In one embodiment, the step of detecting the flatness and consistency of the surface of the diamond substrate in real time and judging the fine polishing effect of the diamond substrate based on the detection result specifically includes: Scanning the surface of the diamond substrate in real time and collecting a surface image of the diamond substrate; Preprocessing the surface image for noise elimination and definition enhancement, constructing a three-dimensional point cloud image of the surface of the diamond substrate, and extracting texture features and topographic features of the diamond substrate; Calculating the roughness and uniformity in the randomly selected area according to the texture characteristics and topographic characteristics; Comparing the calculated result with the preset roughness and uniformity to determine whether the diamond substrate reaches the preset fine polishing surface; If the diamond substrate does not reach the preset fine polishing surface, the first preset speed, the second preset speed and the preset pressure value are adjusted to continue fine polishing; if the diamond substrate reaches the preset fine polishing surface, the first motor, the second motor and the linear motor are stopped to complete the fine polishing process.

[0061] In the above embodiments, when scanning the surface of the diamond substrate in real time, a high-precision optical scanning device, such as a laser scanner or an optical coherence tomography (OCT) scanner, is usually used to ensure that tiny surface undulations and defects can be captured. The acquired surface image is then processed by dedicated software, which can automatically identify and remove noise in the image, while enhancing the contrast and clarity of the image, so as to more accurately construct a three-dimensional point cloud map.

[0062] After constructing the 3D point cloud, the system will automatically extract the texture and topographic features of the diamond substrate surface. Texture features include the microstructure and pattern of the surface, while topographic features involve the macroscopic geometry of the surface. By analyzing these features, the system can calculate the roughness and uniformity of the surface. Roughness refers to the size of the microscopic unevenness of the surface, while uniformity reflects the consistency of the surface flatness.

[0063] The calculated roughness and uniformity will be compared with the preset standard values. The preset standard values ​​are set according to the application requirements of the diamond substrate, such as the extremely high requirements for the flatness and consistency of the substrate surface in semiconductor manufacturing. If the calculation results show that the surface roughness and uniformity of the diamond substrate do not meet the preset standards, the system will automatically adjust the key parameters in the fine polishing process, such as the first preset speed, the second preset speed and the preset pressure value. The adjustment of these parameters is achieved by controlling the movement of the first motor, the second motor and the linear motor to ensure that the fine polishing process can respond to the specific conditions of the substrate surface, thereby achieving a better fine polishing effect.

[0064] When the surface roughness and uniformity of the diamond substrate reach the preset standard, the system will stop the movement of all motors and the fine polishing process will be completed. At this point, the flatness and consistency of the diamond substrate surface have reached the expected fine polishing surface type and can be processed or used later. The entire fine polishing process is highly automated and intelligent, which greatly improves the processing efficiency and quality of the diamond substrate.

[0065] In one embodiment, the number of the diamond substrates is 3, and the preset size of the diamond substrate is 2 inches or 4 inches.

[0066] In the above embodiment, by processing a plurality of diamond substrates on a carrier plate at the same time, the processing efficiency is greatly improved, the processing volume per unit time is significantly increased, and the production cost can be effectively reduced.

[0067] In one embodiment, the polishing pad is a damping cloth polishing pad, the first preset rotation speed is 51-57 revolutions per minute, the second preset rotation speed is 17-19 revolutions per minute, and the ratio of the first preset rotation speed to the second preset rotation speed is three to one, and the preset pressure value is 200-400 grams per square centimeter.

[0068] In the above embodiment, the damping cloth material of the polishing pad can provide appropriate friction and elasticity to ensure that uniform pressure is applied to the surface of the diamond substrate during fine polishing. This material of the polishing pad helps to improve the polishing efficiency and reduce damage to the substrate surface.

[0069] The first preset speed and the second preset speed are set based on comprehensive consideration of the substrate material characteristics and the polishing pad performance to ensure the best polishing effect during the polishing process. The speed is independently controlled, and the speed of the upper polishing pad is one-third of the speed of the lower carrier plate. Correspondingly, the ring gear and the center gear are controlled at a suitable speed. The preferred speed is: 54rpm for the lower carrier plate, 18rpm for the upper polishing pad, 5.25rpm for the ring gear, and 8.5rpm for the center gear.

[0070] The preset pressure is set to maintain appropriate contact force between the substrate surface and the polishing pad during the polishing process, so as to achieve a uniform polishing effect. The polishing pressure can be 200g / cm2-400g / cm2, and the most preferred pressure value is 300 grams per square centimeter. The specific pressure is obtained through experiments and optimization, aiming to ensure the flatness and consistency of the substrate surface, while avoiding damage to the substrate surface caused by excessive pressure. Processing under this pressure can ensure the efficiency of wafer removal without causing wafer scratches.

[0071] In actual operation, the system automatically adjusts the motor motion parameters and the pressure of the polishing pad according to the initial surface condition of the diamond substrate and the preset fine polishing standard. By real-time monitoring of the roughness and uniformity of the substrate surface, the system can intelligently control the polishing process until the preset fine polishing effect is achieved. The entire process does not require manual intervention, which greatly improves production efficiency and the stability of fine polishing quality.

[0072] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fine polishing method for a diamond substrate, characterized in that: include: Providing a plurality of diamond substrates and carrier plates of preset sizes, and gluing and fixing the diamond substrates on the carrier plates; Providing a polishing pad, and bringing a diamond substrate fixed on the carrier plate into contact with the polishing pad; supplying polishing liquid to the diamond substrate in a circulation mode or a drip mode; The carrier plate is controlled to rotate at a first preset rotation speed, the polishing pad is controlled to rotate at a second preset rotation speed, and the polishing pad is controlled to apply pressure to the diamond substrate for fine polishing at a preset pressure, so that the diamond substrate forms a preset fine polishing surface.

2. A fine polishing method for a diamond substrate according to claim 1, characterized in that: The step of sticking and fixing the diamond substrate on the carrier plate specifically includes: Selecting a plurality of diamond substrates of preset sizes, and pre-treating the diamond substrates in a vacuum environment; Evenly coating a preset adhesive on the workbench of the carrier plate, and bonding the diamond substrate to the workbench of the carrier plate; Performing a vacuum treatment on the bonding interface between the diamond substrate and the carrier plate to remove bubbles in the bonding interface so that the diamond substrate and the carrier plate are closely attached; Applying a constant pressing force to the bonded diamond substrate; The preset adhesive is heated at a preset heating temperature to solidify the preset adhesive.

3. A fine polishing method for a diamond substrate according to claim 2, characterized in that: The step of pre-treating the diamond substrate in a vacuum environment specifically comprises: Placing the diamond substrate in a vacuum chamber, and reducing the pressure of the vacuum chamber to a preset vacuum degree to remove gas from the surface of the diamond substrate; Performing a plasma cleaning process on the diamond substrate in the vacuum chamber to remove organic matter and impurity particles on the surface of the diamond substrate; The diamond substrate after the plasma cleaning treatment is baked at a preset baking temperature to remove trace moisture and volatile substances on the surface of the diamond substrate.

4. A fine polishing method for a diamond substrate according to claim 2, characterized in that: The step of uniformly coating a preset adhesive on the workbench of the carrier plate and bonding the diamond substrate to the workbench of the carrier plate specifically includes: Controlling the carrier plate to rotate at a speed of 10 to 30 revolutions per minute; Adhesive wax is used as the preset adhesive, and the adhesive wax having a thickness of 10 microns to 50 microns is evenly coated on the workbench of the carrier plate; After coating is completed, the carrier plate is controlled to stop rotating, so that the adhesive wax is self-leveled on the workbench of the carrier plate.

5. A fine polishing method for a diamond substrate according to claim 2, characterized in that: The step of heating the preset adhesive at a preset heating temperature to solidify the preset adhesive specifically includes: Placing the diamond substrate in a heating device, and setting a preset heating temperature for the heating device according to the curing characteristics of the preset adhesive; Starting the heating device and gradually raising the temperature to the preset heating temperature in a multi-stage heating manner; The preset adhesive is subjected to temperature detection, and after the preset adhesive reaches a preset heating temperature, the preset adhesive is heated for a preset time to complete the curing of the preset adhesive.

6. A fine polishing method for a diamond substrate according to claim 1, characterized in that: The step of supplying polishing liquid to the diamond substrate in a circulation mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; Using a liquid supply pump to transport the polishing liquid from the liquid storage tank to the surface of the polishing pad, so that the polishing liquid evenly covers the diamond substrate at a flow rate of 5-15 liters per minute; Building a filter and a reflux pipeline, wherein the reflux pipeline is connected to the liquid storage tank, and the filter is arranged in the reflux pipeline, so that the polishing liquid can be circulated; The step of supplying polishing liquid to the diamond substrate in a drip mode specifically comprises: Providing a liquid storage tank, in which a polishing liquid with a preset concentration is placed; The polishing liquid is dripped from the liquid storage tank to the polishing pad at a flow rate of 150-300 ml per minute using a metering pump.

7. A fine polishing method for a diamond substrate according to claim 1, characterized in that: The step of controlling the carrier plate to rotate at a first preset speed, controlling the polishing pad to rotate at a second preset speed, and controlling the polishing pad to perform pressure polishing on the diamond substrate at a preset pressure specifically includes: Setting a first preset rotation speed of the carrier plate and a second preset rotation speed and a preset pressure value of the polishing pad, driving the carrier plate to rotate at the first preset rotation speed by a first motor, driving the polishing pad to rotate at the second preset rotation speed by a second motor, and driving the polishing pad to perform fine polishing on the diamond substrate at a preset pressure value by a linear motor provided with a pressure sensor; Real-time detection of the flatness and consistency of the surface of the diamond substrate, and judging the fine polishing effect of the diamond substrate based on the detection results; The first preset rotation speed, the second preset rotation speed and the preset pressure value are adjusted according to the fine polishing effect, so that the diamond substrate forms a preset fine polishing surface shape.

8. A fine polishing method for a diamond substrate according to claim 7, characterized in that: The step of detecting the flatness and consistency of the surface of the diamond substrate in real time and judging the fine polishing effect of the diamond substrate based on the detection result specifically includes: Scanning the surface of the diamond substrate in real time and collecting a surface image of the diamond substrate; Preprocessing the surface image for noise elimination and definition enhancement, constructing a three-dimensional point cloud image of the surface of the diamond substrate, and extracting texture features and topographic features of the diamond substrate; Calculating the roughness and uniformity in the randomly selected area according to the texture characteristics and topographic characteristics; Comparing the calculated result with the preset roughness and uniformity to determine whether the diamond substrate reaches the preset fine polishing surface; If the diamond substrate does not reach the preset fine polishing surface, the first preset speed, the second preset speed and the preset pressure value are adjusted to continue fine polishing; if the diamond substrate reaches the preset fine polishing surface, the first motor, the second motor and the linear motor are stopped to complete the fine polishing process.

9. The fine polishing method for a diamond substrate according to claim 1, characterized in that: The number of the diamond substrates is 3, and the preset size of the diamond substrate is 2 inches or 4 inches.

10. The fine polishing method for a diamond substrate according to claim 1, characterized in that: The polishing pad is a damping cloth polishing pad, the first preset rotation speed is 51-57 revolutions per minute, the second preset rotation speed is 17-19 revolutions per minute, and the ratio of the first preset rotation speed to the second preset rotation speed is three to one, and the preset pressure value is 200-400 grams per square centimeter.

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