Precursor powder manufacturing method, ceramic part manufacturing method and ceramic part

Abstract

The invention provides a precursor powder manufacturing method, a ceramic part manufacturing method and a ceramic part. The preparation method of the precursor powder comprises the following steps: obtaining pure ceramic powder as a raw material; carrying out ball milling on the raw materials by adopting tungsten carbide grinding balls to obtain primary precursor powder; wherein the ball milling process comprises a first ball milling stage and at least one second ball milling stage; the ball milling speed of the first ball milling stage is smaller than that of the second ball milling stage; and sieving the primary precursor powder to obtain the precursor powder. By utilizing the characteristics of high hardness, high wear resistance and high density of the tungsten carbide material, the raw material is subjected to ball milling, so that the volume of the grinding ball can be as small as possible under the condition that the weight of the tungsten carbide grinding ball is enough to crush the raw material particles, and the grinding ball can be in full contact with the raw material particles, so that the grinding efficiency is improved. The granularity of raw materials is as small as possible within a certain ball milling time, and the time required by the ball milling step can be shortened.

Description

Technical Field

[0001] This invention belongs to the field of ceramic manufacturing technology, specifically relating to a method for preparing precursor powder, a method for manufacturing ceramic parts, and ceramic parts. Background Technology

[0002] Due to their properties such as hardness, wear resistance, electrical insulation, resistance to acid and alkali corrosion, fire resistance, impermeability to liquids and gases, and good chemical stability, ceramics have been widely used in the field of integrated circuits. They are especially indispensable process materials in plasma etching processes. Specifically, structures such as ceramic windows, nozzles, focusing rings, and insulating rings in the process chamber are typically made of ceramic materials. Furthermore, high-purity yttrium oxide ceramics, due to their low porosity and excellent etching resistance, are currently used in ICP etching machines as nozzles and other components. In the etching process, to ensure etching intensity, corrosive gases such as CF4, Cl2, and O2 are typically selected as process gases. Therefore, ceramic parts are subjected to corrosion from process gases and plasma bombardment during the etching process, as well as significant pressure changes. Thus, the process requires ceramic parts to have high hardness, good crack propagation resistance, and high etching resistance. However, if the ceramic material does not possess the mechanical properties required by the process, the ceramic component is prone to cracking due to impacts or frequent pressure changes during installation, posing a risk of damage to the ceramic component and contamination of the process chamber. Furthermore, the ceramic components used in existing semiconductor process equipment are typically composed of alumina as the substrate with a yttrium oxide coating on the surface. Therefore, damage to the yttrium oxide coating on such ceramic components exposes the alumina substrate, significantly reducing the etching resistance of the ceramic component and greatly increasing the risk of contamination of the process chamber.

[0003] Therefore, how to manufacture ceramic parts with high hardness and resistance to breakage has become an urgent problem to be solved in this field. Summary of the Invention

[0004] This invention at least partially solves the problem of difficulty in obtaining high-hardness ceramic parts, and provides a method for preparing precursor powder, a method for manufacturing ceramic parts, and ceramic parts.

[0005] This invention provides a method for preparing precursor powder, which is applied to the manufacturing process of ceramic parts.

[0006] The method for preparing the precursor powder includes:

[0007] Obtain the raw materials; the raw materials are pure ceramic powder;

[0008] The raw material is ball-milled using tungsten carbide grinding balls to obtain a primary precursor powder; wherein the ball milling process includes a first ball milling stage and at least one second ball milling stage; the ball milling speed of the first ball milling stage is lower than the ball milling speed of the second ball milling stage;

[0009] The primary precursor powder is sieved to obtain the precursor powder.

[0010] Optionally, there are multiple tungsten carbide grinding balls, including multiple first tungsten carbide grinding balls and multiple second tungsten carbide grinding balls; wherein the diameter of the first tungsten carbide grinding balls is larger than the diameter of the second tungsten carbide grinding balls.

[0011] Optionally, the step of ball milling the raw materials using tungsten carbide grinding balls includes:

[0012] A plurality of first tungsten carbide grinding balls, a plurality of second tungsten carbide grinding balls, and the raw material are placed in the container of a ball mill;

[0013] During the first ball milling stage, the container is driven to rotate at a first rotational speed for a first duration;

[0014] During the second ball milling stage, the container is driven to rotate at a second rotational speed for a second duration;

[0015] Wherein, the second rotational speed is greater than the first rotational speed; and the second duration is greater than the first duration.

[0016] Optionally, the ball-to-powder mass ratio in the ball milling process ranges from 15:1 to 25:1.

[0017] Optionally, the first rotational speed range is 100 r / min to 200 r / min;

[0018] The second speed range is 900 r / min to 1500 r / min.

[0019] Optionally, the first duration ranges from 5 min to 10 min;

[0020] The second duration range is 90 min to 150 min.

[0021] Optionally, the diameter of the first tungsten carbide grinding ball ranges from 5 mm to 8 mm;

[0022] The diameter of the second tungsten carbide grinding ball ranges from 1 mm to 3 mm.

[0023] Optionally, the ratio of the first tungsten carbide grinding ball to the second tungsten carbide grinding ball is in the range of 1:4 to 1:6.

[0024] Optionally, the step of placing a plurality of first tungsten carbide grinding balls, a plurality of second tungsten carbide grinding balls, and the raw material in a container includes:

[0025] A plurality of the second tungsten carbide grinding balls and the raw material are placed in the container;

[0026] A plurality of the first tungsten carbide grinding balls are placed in the container to place the first tungsten carbide grinding balls on top of the second tungsten carbide grinding balls and the raw material.

[0027] Optionally, the step of sieving the primary precursor powder includes:

[0028] The primary precursor powder is sieved using a sieve with a first mesh size, and the secondary precursor powder that passes through the sieve with the first mesh size is obtained.

[0029] The secondary precursor powder is sieved using a sieve with a second mesh size, and the powder that does not pass through the sieve with the second mesh size is obtained and used as the precursor powder; wherein, the second mesh size is greater than the first mesh size.

[0030] As another technical solution, the present invention also provides a method for manufacturing ceramic parts, which includes:

[0031] Obtaining raw materials;

[0032] The raw materials are prepared into precursor powder using the precursor powder preparation method described above;

[0033] The precursor powder is obtained, placed in a rigid mold, and a specified pressure is applied to the precursor powder and held for a specified time to form a preform of a specified shape.

[0034] The blank is sintered to a ceramic state.

[0035] Optionally, the step of obtaining raw materials includes:

[0036] Obtain the raw material with a preset purity; wherein the preset purity is greater than or equal to 99%; the raw material includes yttrium oxide.

[0037] As another technical solution, the present invention also provides a ceramic part for use in semiconductor process equipment, which is manufactured using the ceramic part manufacturing method described above.

[0038] Optionally, the average grain size of the ceramic part is less than 900 nm.

[0039] The present invention has the following beneficial effects:

[0040] The precursor powder preparation method provided in this invention uses tungsten carbide grinding balls to ball mill the raw materials, taking advantage of the high hardness and high wear resistance of tungsten carbide. Furthermore, tungsten carbide also has a high density; therefore, while ensuring the weight of the grinding balls is sufficient to crush the raw material particles, the volume of the grinding balls can be made as small as possible. The smaller the volume of the grinding balls, the more fully they can contact the raw material particles, thus minimizing the particle size of the raw materials within a certain ball milling time. In other words, the time required to grind the raw materials to the desired size is shorter.

[0041] Moreover, since the tungsten carbide grinding balls have a volume sufficient to allow the raw material particles to fully contact the surface of the grinding balls, there is no need to add anhydrous ethanol to promote the flow of raw materials during the ball milling process. This avoids the risk of anhydrous ethanol exploding during high-speed ball milling. Furthermore, the rotational speed of the container during the ball milling process can be further increased, thereby increasing the grinding kinetic energy when the grinding balls impact the raw material particles, thus improving the degree of grinding of the raw materials and reducing the particle size of the raw materials.

[0042] Moreover, since the ball milling process can achieve a high milling speed, and the heavy tungsten carbide grinding balls used in this embodiment can provide a great deal of grinding kinetic energy, the grinding balls will give the raw material particles a very high internal energy when they collide with the raw material particles. This provides enough energy to overcome the sintering barrier in the subsequent sintering steps, so there is no need to add a step in the subsequent process to increase the energy to overcome the barrier, which can simplify the entire ceramic part manufacturing process.

[0043] Furthermore, the precursor powder preparation method provided in this embodiment of the invention also proposes a segmented ball milling process. Specifically, the ball milling process includes a first ball milling stage with a lower ball milling speed and at least one second ball milling stage with a higher ball milling speed. In the first ball milling stage, the grinding balls and raw materials are initially mixed and initially accelerated, while in the second ball milling stage, the raw materials are ball milled at high speed. This reduces the ball milling speed difference between the first and second ball milling stages. Thus, when transitioning from the first to the second ball milling stage, the acceleration of the ball milling equipment does not need to be too large, so that the ball milling equipment does not generate excessive centrifugal force. This avoids the raw materials being subjected to excessive centrifugal force and concentrating in one place, thereby avoiding problems such as agglomeration, clumping, and sticking to the wall, and ensuring the uniformity of the ball milling process.

[0044] The ceramic part manufacturing method provided in this embodiment of the invention uses the precursor powder preparation method proposed in this embodiment to prepare the precursor powder for making the green body. The precursor powder preparation method can achieve a smaller and more uniform particle size of the raw materials through ball milling, so that the particle size inside the green body is smaller, thereby making the green body present a more compact structure and improving hardness. As a result, after sintering, the internal grain size of the ceramic part can be reduced, the grain boundary volume content can be increased, crack propagation can be hindered, and it is beneficial to improve the mechanical properties of ceramics.

[0045] Furthermore, since no anhydrous ethanol is added during ball milling, a drying step to remove the anhydrous ethanol is not required during ceramic part manufacturing. Moreover, as mentioned above, the precursor powder preparation method proposed in this embodiment provides a high-temperature, high-speed grinding environment, which provides some of the energy required for the ceramic solid-phase reaction barrier while achieving powder crushing and particle size reduction, eliminating the need for an additional powder energy supply step. Therefore, the ceramic part manufacturing method provided by this embodiment can also simplify the process and shorten the manufacturing time. Furthermore, the aforementioned precursor powder preparation method can achieve a shorter time required to grind raw materials to the desired size, which also shortens the ceramic part manufacturing time. Attached Figure Description

[0046] Figure 1 This is a flowchart of a ceramic part manufacturing method in related technologies;

[0047] Figure 2 This is another flowchart of a ceramic part manufacturing method in related technologies;

[0048] Figure 3 This is a flowchart of a method for preparing precursor powder according to an embodiment of the present invention;

[0049] Figure 4 This is another flowchart of the precursor powder preparation method proposed in the embodiments of the present invention;

[0050] Figure 5A This is a schematic diagram of the internal condition of the ball mill container during the first ball milling stage in step S12 of this embodiment of the invention.

[0051] Figure 5B This is a schematic diagram of the internal condition of the ball mill container during the second ball milling stage in step S12 of this embodiment of the invention.

[0052] Figure 6 This is a schematic diagram of the inside of the ball mill container after step S121 of this embodiment of the invention is completed;

[0053] Figure 7 This is a flowchart of a ceramic part manufacturing method proposed in an embodiment of the present invention;

[0054] Figure 8 This is another flowchart of the ceramic part manufacturing method proposed in the embodiments of the present invention;

[0055] Figure 9 A partial microscopic photograph of yttrium oxide precursor powder prepared using the precursor powder preparation method proposed in this embodiment;

[0056] Figure 10 A partial microscopic photograph of yttrium oxide precursor powder prepared using the precursor powder preparation method in the relevant technical solution;

[0057] Figure 11 Microscopic morphology photographs of yttrium oxide ceramic parts manufactured using the ceramic part manufacturing method proposed in this embodiment;

[0058] Figure 12 Microscopic morphology photographs of yttrium oxide ceramic parts manufactured using the ceramic part manufacturing methods in the relevant technical solutions;

[0059] Figure 13 A statistical chart showing the particle size distribution of yttrium oxide precursor powder prepared using the precursor powder preparation method proposed in this embodiment;

[0060] Figure 14 These are microscopic images of yttrium oxide ceramic parts manufactured using the ceramic part manufacturing method proposed in this embodiment after acid etching.

[0061] Figure 15 This is a microscopic image of a yttrium oxide ceramic part manufactured using the relevant technical solution and subjected to acid etching. Detailed Implementation

[0062] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0063] It is understood that the specific embodiments and accompanying drawings described herein are merely for explaining the invention and are not intended to limit the invention.

[0064] It is understood that, without conflict, the various embodiments of the present invention and the features thereof can be combined with each other.

[0065] It is understood that, for ease of description, the accompanying drawings of this invention only show the parts related to the embodiments of this invention, while the parts unrelated to the embodiments of this invention are not shown in the drawings.

[0066] It is understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of the embodiments of the present invention may occur in a different order than that marked in the accompanying drawings.

[0067] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

[0068] Currently, such as Figure 1 As shown, the fabrication process of ceramic parts used in semiconductor process equipment mainly includes the following steps:

[0069] S01. Precursor powder preparation steps: The raw material powder is crushed into the desired size by ball milling so that the precursor powder particles are small particles with uniform particle size, and the powder obtained by ball milling is sieved.

[0070] S02, Granulation and molding steps: Use a binder to bind and granulate the precursor powder, press the precursor powder into the desired shape, and then remove the previously added binder to form a green body.

[0071] S03. Ceramic sintering steps: The green body is sintered at high temperature to obtain ceramic parts.

[0072] In practical applications, ceramic components installed in semiconductor process equipment need to withstand extreme conditions such as long-term plasma bombardment and frequent pressure changes. Therefore, the process requires that ceramic components will not crack after long-term operation in order to maximize their service life. Ceramic components that meet these requirements need to have good etching resistance, good crack propagation resistance, and extremely high hardness.

[0073] From a macro perspective, the hardness of ceramic parts can be improved by selecting the type of raw materials. Specifically, some related technical solutions involve adding solid solution components that can increase the hardness of ceramic parts to raw materials with strong corrosion resistance; for example, Figure 2As shown, prior to step S01, the relevant technical solution also includes a raw material preparation step S00: obtaining raw materials, adding a certain proportion of solid solution components to the raw materials, and drying the raw materials as a whole. For example, since yttrium oxide ceramics have good etching resistance, and zirconia ceramics and alumina ceramics have high hardness, a certain proportion of zirconia or alumina can be added to the raw materials during the fabrication of yttrium oxide ceramic parts to obtain mixed precursor powders, which are then sintered into zirconia or alumina solid solution yttrium oxide ceramic parts to improve the hardness of the yttrium oxide ceramic parts. However, these solid solution components have poor etching resistance, resulting in a sacrifice of etching resistance while improving the hardness of the ceramic parts. Moreover, the multiple grain types in such mixed material ceramic parts are different, and if the solid solution components are unevenly distributed, the stress distribution within the grain boundaries between grains will also be uneven, leading to uneven strength distribution of the ceramic parts and a reduction in the overall physical properties of the ceramic parts. Furthermore, the addition of solid solution components such as zirconia may introduce impurities into the semiconductor process equipment. Furthermore, before adding solid solution components, multiple experiments or simulations are required to determine the proportions of the solid solution components, which leads to higher initial design costs.

[0074] At the microscopic level, ceramic parts are composed of closely packed grains connected by grain boundaries. These grain boundaries exert stress on adjacent grains, promoting tighter grain adhesion and hindering crack propagation, thus preventing ceramic fragmentation. Therefore, given a fixed volume and achieving densification, a higher grain boundary content makes crack propagation more difficult, resulting in superior mechanical properties. Based on this principle, some related technical solutions typically improve the density of the green body formed during the forming process by reducing the particle size of the precursor powder, thereby minimizing the size and density of the grains within the sintered ceramic part. Specifically, to grind the precursor powder particles smaller and more uniformly, these solutions often employ higher ball milling speeds and add anhydrous ethanol as the milling medium to improve particle flowability, forming a powder slurry. This increases the contact area between the raw material and the milling balls, ensuring thorough grinding. However, during ball milling, the impact between the grinding balls and the raw materials, as well as the breakage of the raw materials, release heat. Accumulated heat can cause ethanol to expand in volume and even reach its ignition point, posing a risk of explosion. Therefore, to avoid explosions, the rotational speed of the container in existing ball milling processes is typically low, usually not exceeding 400 r / min. However, a lower milling speed results in larger precursor powder particles. Thus, this related technical solution offers limited improvement to the mechanical properties of ceramic parts.

[0075] Furthermore, a series of solid-state reactions occur during ceramic sintering, including physical changes in the crystals and grain boundary diffusion at the crystal-to-crystal interfaces. These solid-state reactions are subject to a reaction barrier; specifically, the reaction will only occur when the reacting materials possess sufficient energy to overcome this barrier. In the case of ceramic sintering, the sintering equipment provides the majority of the energy from these solid-state reactions. Therefore, the energy needed to overcome the barrier must be provided by other process steps to minimize the sintering time. It is easy to understand that the green body needs to be "preheated" before ceramic sintering to allow the sintering reaction to begin rapidly. In related technologies, such as... Figure 2 As shown, in the precursor powder preparation step, the precursor powder usually needs to be calcined after the ball milling process to provide energy to overcome the potential barrier for the aforementioned solid-state reaction; for example, yttrium oxide precursor powder is calcined at around 1000°C before the sintering step. However, the above calcination process may cause larger particles in the precursor powder to fuse with smaller particles under high temperature, resulting in ceramic parts with larger grains in the subsequent sintering step, and uneven grain size distribution, which may also easily lead to lower hardness of the ceramic parts.

[0076] To address the issue of increasing the hardness of ceramic parts, this embodiment primarily focuses on improving the precursor powder preparation step in the ceramic part manufacturing process. Specifically, this embodiment proposes a precursor powder preparation method applicable to the ceramic part manufacturing process, such as... Figure 3 As shown, the method includes:

[0077] S11. Obtain raw materials;

[0078] Specifically, the raw material in step S11 is pure ceramic powder, such as pure yttrium oxide powder. Compared with the above-mentioned related technical solutions, no other solid solution components need to be added to the raw material in this embodiment, so as to avoid the problem of uneven strength distribution of the sintered ceramic parts and to avoid introducing impurities that are not desired in semiconductor processes.

[0079] It should be noted that the "pure ceramic powder" proposed in this invention is a commercially available product well known to those skilled in the art, and under the limitations of existing preparation conditions, the purity of the raw material can reach at least 99%.

[0080] S12. The raw material is ball-milled using tungsten carbide grinding balls to obtain primary precursor powder; this step specifically includes a first ball-milling stage and at least one second ball-milling stage; wherein the ball-milling speed of the first ball-milling stage is less than the ball-milling speed of the main ball-milling stage.

[0081] S13. The primary precursor powder is sieved to obtain the precursor powder.

[0082] Specifically, the principle of the ball milling process used in step S12 above is as follows: Raw materials and grinding balls are loaded into the container of the ball mill, and then the container is driven to rotate. During the rotation of the ball mill container, the grinding balls, under the action of centrifugal force and inertia, undergo relative motion with the raw material powder, causing collisions between grinding balls and between the grinding balls and the container. This breaks down the raw material particles between the grinding balls and between the container and the grinding balls, making the raw material particles smaller and achieving grinding. It is easy to understand that the hardness of the grinding balls should be greater than the hardness of the raw materials to ensure that the raw materials can be broken down when the grinding balls collide with them, and that the grinding balls are not damaged. Moreover, since the ball milling process utilizes the potential energy of the grinding balls to convert into kinetic energy to impact the raw materials, under the condition of a constant container rotation speed, the larger the mass of the grinding balls, the greater the impact force they can exert on the raw materials, and the faster the raw materials can be broken down. Furthermore, the collision requires contact between the grinding balls and the raw materials. Therefore, the larger the contact area between the grinding balls and the raw materials, the more thoroughly the raw materials can be ground. However, as the ball milling process progresses, the raw material particles become smaller and smaller. When the particle size shrinks to a certain extent, the raw material particles may remain in the gaps between multiple grinding balls and cannot make contact with them, thus failing to be ground further. This may result in the raw material particles not being ground to a sufficiently small size. Moreover, since the potential energy of the grinding balls is provided by the rotational power of the container, the rotational speed of the container also affects the force of the grinding balls impacting the raw materials. Specifically, the greater the rotational speed of the container, the greater the force of the grinding balls impacting the raw materials. Therefore, given a fixed weight of grinding balls, the faster the rotational speed of the container, the smaller the particle size of the precursor powder ultimately produced.

[0083] This embodiment proposes using tungsten carbide grinding balls to ball mill the raw materials. Tungsten carbide is characterized by high hardness and high wear resistance, making it suitable for grinding raw materials, such as pure yttrium oxide. Furthermore, tungsten carbide has a high density, reaching 15.63 g / cm³. 3Therefore, under the same weight, the volume of tungsten carbide grinding balls can be smaller, and correspondingly, the gaps between multiple tungsten carbide grinding balls are also smaller, allowing for sufficient contact between the raw material and the grinding balls. It is evident that tungsten carbide grinding balls can be made as small as possible while ensuring sufficient weight to crush the raw material particles, thus maximizing contact between the grinding balls and the raw material particles. Under the condition of a fixed grinding speed and grinding time, the raw material particles can be ground to the smallest possible size, resulting in a precursor powder with a smaller particle size. As mentioned above, the smaller the particle size of the precursor powder, the smaller the grain size of the sintered ceramic, ultimately leading to better densification and increased hardness in the ceramic parts. Therefore, the precursor powder preparation method proposed in this application can effectively improve the hardness of the subsequently sintered ceramic parts, ensure their corrosion resistance, increase their service life, and reduce the risk of damage. From another perspective, the ball milling step proposed in this embodiment can also shorten the time required to grind the raw material to the desired size.

[0084] In related technologies, alumina grinding balls are typically used in ball milling processes. However, alumina has a low density, approximately 3.5 g / cm³. 3 Therefore, in order for the grinding balls to have sufficient weight to crush the raw material particles, the grinding balls need to have a large volume. However, this results in larger gaps between multiple alumina grinding balls, leading to a smaller contact area between the grinding balls and the raw material particles, and consequently, larger raw material particles obtained from the ball milling process. As mentioned above, if anhydrous ethanol is added to the raw material to maintain contact between the grinding balls and the raw material particles, there is a risk that the anhydrous ethanol may explode due to the heat generated during the ball milling process. Therefore, in this case, the ball milling process must be carried out at a low speed to avoid explosion, which still results in larger precursor powder particles. Since the density of the tungsten carbide grinding balls proposed in this embodiment satisfies the condition that the weight is sufficient to crush the raw material particles, the volume of the grinding balls is sufficient to ensure sufficient contact between the grinding ball surface and the raw material particles. Compared with the solutions of related technologies, if anhydrous ethanol is added, the ball milling speed is limited, the energy provided by the ball milling process is reduced, and it is difficult to achieve the ball milling process of this application. Therefore, anhydrous ethanol does not need to be added during the ball milling process of this embodiment. As can be seen, compared with related technologies, this embodiment can avoid the risk of anhydrous ethanol exploding during ball milling. Furthermore, the ball milling process in this embodiment can be carried out at high speed, thereby improving the impact force of the grinding balls when they hit the raw material particles, thus improving the degree of grinding of the raw materials and reducing the size of the raw material particles.

[0085] Furthermore, since the ball milling process proposed in this embodiment can achieve a high milling speed, and the heavy tungsten carbide grinding balls used in this embodiment can provide a large amount of grinding kinetic energy, the impact of the grinding balls with the raw material particles will endow the raw material particles with extremely high internal energy. This provides some of the energy required for the ceramic solid-phase reaction barrier while simultaneously achieving powder crushing and particle size reduction. Therefore, there is no need to add a calcination step in the subsequent process to supplement the barrier energy, thus avoiding the problem of particle growth and size increase of the powder under high temperature conditions caused by the calcination step. It can be seen that, compared with related technical solutions, the precursor powder prepared by the method proposed in this embodiment does not require a subsequent calcination step, avoiding the problem of precursor powder particles becoming larger under high temperature.

[0086] Furthermore, since the anhydrous ethanol introduced into the ball milling process in related technologies is an impurity other than the raw materials, therefore, as Figure 2 As shown, in the precursor powder preparation steps of related technical solutions, a heating and drying step is required after the precursor powder is prepared to promote the evaporation of anhydrous ethanol and remove it. However, as mentioned above, since the ball milling process proposed in this embodiment does not require the addition of anhydrous ethanol, a drying step is not needed after the precursor powder is prepared before proceeding to the subsequent pressing step, thereby simplifying the process and shortening the overall ceramic part manufacturing time. Moreover, as mentioned above, the ball milling step proposed in this embodiment can also shorten the time required to grind the raw materials to the desired size, which also shortens the overall ceramic part manufacturing time. It is evident that, compared to related technical solutions, the precursor powder preparation method proposed in this embodiment can effectively shorten the overall precursor powder preparation process time.

[0087] This embodiment also proposes a ball milling process including a first ball milling stage and at least one second ball milling stage, wherein the ball milling speed in the first ball milling stage is lower than that in the second ball milling stage, such as... Figure 5A As shown, this is to ensure that the raw material 3 is uniformly mixed with multiple tungsten carbide grinding balls 1 in the first ball milling stage, and to achieve preliminary crushing of the raw material 3 particles, so as to initially break down the large-diameter particles in the raw material 3, and to initially accelerate the mixing of the raw material 3 with the multiple tungsten carbide grinding balls 1; and as... Figure 5BAs shown, in the second ball milling stage, the rotational speed of container 2 is increased to enhance the impact energy of the tungsten carbide grinding balls 1 on the raw material 3, thereby further grinding the raw material 3 into smaller particles. Moreover, since the multiple tungsten carbide grinding balls 1 underwent initial acceleration in the first ball milling stage, reducing the speed difference between the first and second ball milling stages, the container 2 does not need to be subjected to a large centrifugal force during the increased rotational speed stage of the second ball milling stage. Consequently, the raw material 3 and the multiple tungsten carbide grinding balls 1 will not be subjected to a large centrifugal force, thus avoiding excessive centrifugal force that could cause the raw material 3 to concentrate in a certain place in container 2, resulting in agglomeration, clumping, and sticking to the wall. This ensures that a uniform precursor powder can be produced in the end. Conversely, if the first ball milling stage is skipped and the second ball milling stage is performed directly, the rotation speed of container 2 will suddenly increase to a high speed, causing the raw material 3 and multiple tungsten carbide grinding balls 1 to be subjected to excessive centrifugal force. This results in most of the raw material 3 being thrown to one side of container 2. Furthermore, under the high-speed impact of the tungsten carbide grinding balls 1, the raw material 3 accumulated on one side of container 2 may be gradually compacted onto the inner wall of container 2, resulting in severe agglomeration. Consequently, most of the raw material 3 particles cannot come into contact with the tungsten carbide grinding balls 1, thus making it impossible to prepare a uniform precursor powder.

[0088] For example, the grinding balls described above can also be made of materials with a density, hardness, and wear resistance greater than tungsten carbide, so as to both increase the density of the grinding balls and ensure that the grinding balls will not deform and be damaged during the grinding process.

[0089] For example, the average particle size of the raw material can be 10 μm.

[0090] In some embodiments, in step S13 above, i.e., the step of sieving the primary precursor powder, a sieve with a first mesh size and a second mesh size can be used. Specifically, step S13 includes:

[0091] The primary precursor powder is sieved using a sieve with a first mesh size, and the secondary precursor powder that passes through the sieve with the first mesh size is obtained.

[0092] The secondary precursor powder is sieved using a sieve with a second mesh size, and the powder that does not pass through the sieve with the second mesh size is obtained and used as the precursor powder.

[0093] In this way, by first sieving the primary precursor powder with a first-mesh sieve and obtaining the portion of powder that passes through the sieve, the excessively large particles in the primary precursor powder are removed, thus ensuring that the precursor powder particle size is not too large. Then, the above-mentioned portion of powder is further sieved with a second-mesh sieve, and the portion of powder that does not pass through the sieve is obtained and used as the precursor powder. This removes the excessively small particles in the primary precursor powder, thus ensuring the uniformity of the powder particle size and preventing large grains from absorbing small grains and becoming larger grains during sintering. This further ensures that the sintered ceramic has a small and uniform grain size.

[0094] For example, the first mesh count can be 200 meshes, and the second mesh count can be 400 meshes.

[0095] In some embodiments, the ball milling process described above uses multiple tungsten carbide grinding balls, specifically multiple first tungsten carbide grinding balls and multiple second tungsten carbide grinding balls. The diameter of the first tungsten carbide grinding balls is larger than the diameter of the second tungsten carbide grinding balls, meaning the volume of the first tungsten carbide grinding balls is larger than the volume of the second tungsten carbide grinding balls. Specifically, the larger first tungsten carbide grinding balls can utilize their greater weight to crush larger particles in the raw material, thereby improving the efficiency of the ball milling process; while the smaller second tungsten carbide grinding balls have a larger contact area with the raw material, enabling them to further crush the raw material particles, making them smaller and improving the uniformity of the ball milling process. Moreover, using both large and small tungsten carbide grinding balls simultaneously allows for obtaining the desired particle size precursor powder in a single ball milling process, eliminating the need for multiple ball milling processes, thus simplifying the process and shortening the process time.

[0096] In some specific embodiments, the ball-to-powder mass ratio in the ball milling process, that is, the ratio between the total mass of the grinding balls and the total mass of the raw materials, ranges from 15:1 to 25:1. Within this range, it can be ensured that the raw material particles can be subjected to sufficiently high impact energy, thereby ensuring that the raw materials can be fully ground, and that there is not too little raw material, which would cause the grinding balls to only contact a small amount of raw material or even not contact the raw material at all, resulting in a waste of process energy.

[0097] In some specific embodiments, the diameter of the first tungsten carbide grinding ball ranges from 5 mm to 8 mm. As mentioned above, since tungsten carbide material has a high density, the volume of the tungsten carbide grinding ball can be as small as possible. Therefore, the contact area between the first tungsten carbide grinding ball and the raw material can be increased as much as possible, while the weight of the first tungsten carbide grinding ball is also sufficient to crush large-diameter particles.

[0098] The diameter of the second tungsten carbide grinding ball ranges from 1 mm to 3 mm. As mentioned above, due to the high density of tungsten carbide material, the volume of the tungsten carbide grinding ball can be as small as possible. Therefore, even if the diameter of the second tungsten carbide grinding ball is in the range of 1 mm to 3 mm, it is sufficient to crush the raw material particles.

[0099] Furthermore, in some specific embodiments, the ratio of the first tungsten carbide grinding ball to the second tungsten carbide grinding ball is in the range of 1:4 to 1:6. Within this ratio range, it can be ensured that the number of the first tungsten carbide grinding balls is sufficient to crush the larger particles in the raw material, while ensuring that the second tungsten carbide grinding balls can further crush the raw material particles that have been crushed once or multiple times.

[0100] In some embodiments, such as Figure 4 As shown, step S12 above, which is the step of ball milling the raw material using tungsten carbide grinding balls, specifically includes:

[0101] S121. Place multiple first tungsten carbide grinding balls, multiple second tungsten carbide grinding balls, and raw materials into the container of the ball mill;

[0102] S122. In the first ball milling stage described above, the container is driven to rotate at a first rotation speed for a first duration to perform preliminary ball milling for a first duration.

[0103] In the second ball milling stage described above, the container is driven to rotate at a second rotation speed for a second duration to further ball mill for a second duration; wherein the second rotation speed is greater than the first rotation speed and the second duration is greater than the first duration.

[0104] Specifically, the first ball milling stage is used to initially accelerate the tungsten carbide grinding balls and initially mix the raw materials with multiple tungsten carbide grinding balls, while the second ball milling stage is used to drive the tungsten carbide grinding balls to crush the raw material particles. It can be seen that the second ball milling stage plays the main grinding role, while the first ball milling stage only plays a buffering role. Therefore, in order to improve the ball milling efficiency, the time required for the first ball milling stage can be less than the time required for the second ball milling stage.

[0105] For example, there is only one second ball milling stage, that is, the ball milling process in step S12 is a "two-stage" ball milling process to improve the overall efficiency of the ball milling process.

[0106] For example, there may be multiple second ball milling stages; and the second rotation speed values ​​and second durations of the multiple second ball milling stages may be the same or different.

[0107] In some specific embodiments, the first rotational speed range is 100 r / min to 200 r / min. Within this speed range, the raw material can be driven to mix evenly with multiple tungsten carbide grinding balls, which is sufficient to initially crush large-diameter particles in the raw material. Moreover, while avoiding excessive centrifugal force on the raw material and multiple tungsten carbide grinding balls, the difference between the first and second rotational speeds can be reduced, thereby achieving a buffering effect on the second ball milling stage.

[0108] Furthermore, the second rotational speed range is 900 r / min to 1500 r / min. Within this speed range, the energy of multiple tungsten carbide grinding balls is sufficient to grind the raw material particles to the desired particle size, and the problem of the raw material being compacted against the inner wall of the container due to excessive rotational speed will not occur.

[0109] In some specific embodiments, the first time range is 5 min to 10 min, which allows multiple tungsten carbide grinding balls to initially crush large-diameter particles in the raw materials; the second time range is 90 min to 150 min, which ensures that the ball milling time will not be too long, thereby minimizing the risk of the raw material powder being compacted on the inner wall of the container, and ensuring that the raw material particles are ground to the particle size desired by the process.

[0110] In some embodiments, such as Figure 6 As shown, step S121, namely, the step of placing a plurality of first tungsten carbide grinding balls 11, a plurality of second tungsten carbide grinding balls 12, and raw materials in container 2, specifically includes:

[0111] Multiple second tungsten carbide grinding balls 12 and raw material 3 are placed in container 2;

[0112] Multiple first tungsten carbide grinding balls 11 are placed in container 2, so that the first tungsten carbide grinding balls 11 are placed on top of second tungsten carbide grinding balls 12 and raw material 3. In this way, the multiple second tungsten carbide grinding balls 12 can preferentially mix with the raw material 3 to increase the contact area between the raw material 3 and the grinding balls; while the multiple first tungsten carbide grinding balls 11 are located on one side of the raw material, so that when the container rotates, the multiple tungsten carbide grinding balls can impact the raw material 3 from the other side to increase the impact force on the raw material, thereby accelerating the ball milling process.

[0113] For example, the container of the ball mill is a tungsten carbide container, which has sufficient strength and hardness to withstand the impact of multiple tungsten carbide grinding balls, and its wear resistance is also sufficient to withstand the high-speed friction between the tungsten carbide grinding balls and the raw material particles.

[0114] It should be noted that the aforementioned precursor powder is not limited to the production of yttrium oxide precursor powder. It can also be used as a precursor powder for ceramic materials such as alumina or zirconium oxide. However, process parameters such as ball mill speed, ball milling process duration, grinding ball size and shape, grinding ball material and ball-to-powder ratio need to be adjusted according to actual process requirements.

[0115] Figure 9 and Figure 10 Partial microscopic photographs of yttrium oxide precursor powder prepared using the precursor powder preparation methods provided in this embodiment and related technical solutions are shown respectively. It is clearly visible that, compared with related technical solutions, the yttrium oxide precursor powder prepared using the precursor powder preparation method of this embodiment has smaller particles and more uniform size, and can avoid the problem of precursor powder agglomeration.

[0116] As another technical solution, such as Figure 7 As shown, this embodiment also proposes a method for manufacturing ceramic parts, which includes:

[0117] S1. Precursor powder preparation steps: The raw materials are made into precursor powder using the precursor powder preparation method described above;

[0118] S2. Molding Steps: Obtain precursor powder, place the precursor powder in a rigid mold, apply a specified pressure to the precursor powder and hold it for a specified time to form a blank of a specified shape.

[0119] S3. Ceramic sintering step: Sinter the green body to the ceramic state.

[0120] The ceramic part manufacturing method proposed in this embodiment uses the aforementioned precursor powder preparation method to produce precursor powder. As described above, the precursor powder preparation steps in this embodiment can obtain precursor powder with small and uniform particle size without adding anhydrous ethanol, thereby enabling sintering into ceramic parts with high hardness and etching resistance. Moreover, since the precursor powder produced by this method does not contain anhydrous ethanol, the drying step for removing anhydrous ethanol can be omitted in the molding step of this embodiment.

[0121] Furthermore, as mentioned above, the precursor powder preparation method used in this embodiment can achieve a high ball milling speed, and the ball milling process using tungsten carbide grinding balls can provide extremely high grinding kinetic energy. Therefore, when the grinding balls collide with the raw material particles, the raw material particles will be endowed with extremely high internal energy. This provides some of the energy required for the ceramic solid-phase reaction barrier while simultaneously achieving powder crushing and particle size reduction. Therefore, the ceramic part manufacturing method proposed in this embodiment can eliminate the calcination step used to provide energy for the precursor powder; this simplifies the process and shortens the overall time of the ceramic part manufacturing process. In addition, the aforementioned precursor powder preparation method can achieve a shorter time required to grind the raw materials to the desired size, thereby further shortening the time of the ceramic part manufacturing process.

[0122] Specifically, through multiple tests, the researchers found that the ball milling process provided in the above embodiment takes about 100 minutes, which can save about 8 hours compared to the existing ball milling process. Moreover, the ceramic part manufacturing method proposed in this embodiment does not require a drying step, so the forming step of this embodiment can save about 24 hours compared to the existing ceramic part manufacturing method. Furthermore, the ceramic sintering step in the ceramic part manufacturing method proposed in this embodiment can save about 5 hours compared to the existing ceramic part manufacturing method.

[0123] Furthermore, the process requirements for the green body forming step are: to ensure that the green body can be formed, while also ensuring that the applied pressure is not too excessive, which would cause the particles inside the precursor powder to be too densely packed, thus affecting grain boundary migration during subsequent sintering and hindering the removal of pores, thereby ensuring the quality of the ceramic parts. In related technologies, since existing ball milling processes are difficult to obtain precursor powder with small and uniform particle sizes, existing technical solutions usually require a granulation step first, that is, adding a ceramic binder, such as polyvinyl alcohol (PVA), to the precursor powder to initially improve the adhesion between precursor powder particles, thereby promoting green body bonding without applying excessive pressure; however, this leads to the need for an additional debinding step before the sintering step to allow the ceramic binder in the green body to volatilize under high temperature conditions.

[0124] As mentioned above, compared with related technologies, step S1 proposed in this embodiment can obtain precursor powder with a smaller particle size, such as reaching the nanoscale. The precursor powder with a smaller particle size has good adhesion, so it can be directly pressurized to form a green body without excessive pressure, thus eliminating the need to add ceramic binder. This eliminates the steps of adding ceramic binder and removing adhesive, thereby further shortening the overall time of ceramic part manufacturing process.

[0125] For example, in step S3 above, a cold isostatic pressing process can be used to press the precursor powder into a green body.

[0126] In some embodiments, such as Figure 8 As shown, before step S1 above, the following steps are also included:

[0127] S0. Raw material preparation steps: Obtain the raw materials and place them in a glass dish, and cover them with aluminum foil to prevent contamination by impurities; place the glass dish in an oven and dry for 10 to 12 hours at a temperature of 100°C to 120°C.

[0128] This method removes volatile impurities such as water that may be present in the raw materials, ensuring accurate measurement of the raw material quantity. This allows for adaptive adjustments to process conditions in subsequent steps based on the raw material quantity, improving the precision of subsequent processes. Furthermore, the raw material preparation step proposed in this embodiment does not add any solid solution components to the raw materials, thus ensuring their purity. For example, taking pure yttrium oxide powder as the raw material, as shown above, related technical solutions require adding a certain proportion of zirconium oxide or alumina to the pure yttrium oxide powder in the raw material preparation step to sinter it into zirconium oxide or alumina solid solution yttrium oxide ceramic parts in subsequent steps. This increases the hardness of the ceramic parts but reduces their etching resistance. In contrast, the raw material preparation step S0 proposed in this embodiment obtains dry, pure yttrium oxide powder, providing it for subsequent precursor powder preparation steps and ensuring that the subsequent ceramic sintering step yields impurity-free yttrium oxide ceramic parts, thereby guaranteeing good etching resistance.

[0129] In some embodiments, step S3 described above can employ a conventional pressureless sintering process to sinter the green body to a ceramic state. Specifically, the conventional pressureless sintering process has lower requirements for the sintering equipment, thus reducing process costs.

[0130] For example, a muffle furnace can be used to sinter the aforementioned green body. For instance, in the sintering step, the green body can be placed in the muffle furnace first, and the internal temperature of the muffle furnace can be controlled to rise from room temperature to 1550℃~1650℃ at a preset heating rate, and then held at that temperature; finally, heating is stopped, and the green body is allowed to cool naturally to room temperature along with the muffle furnace to obtain the ceramic part. In related technologies, the sintering temperature of the green body needs to reach 1750℃ or higher. It can be seen that this embodiment, by employing the precursor powder preparation method described above, utilizes ball milling to provide the precursor powder with the energy needed to overcome the potential barrier, which can share the energy required for the ceramic solid-state reaction, thereby reducing the thermal energy required for the sintering step, and thus saving energy and reducing manufacturing costs.

[0131] In other embodiments, the above-mentioned ceramic sintering step can employ a special sintering process, which adds process conditions such as hot pressing sintering and spark plasma sintering to the traditional pressureless sintering process to promote ceramic grain boundary diffusion, thereby enabling rapid sintering of ceramic parts.

[0132] It should be noted that the above-mentioned ceramic parts manufacturing method is not limited to the production of yttrium oxide ceramic parts. It can also be applied to industrial ceramics such as alumina ceramics or zirconia ceramics. However, the above-mentioned process conditions and process parameters need to be adjusted according to the actual process requirements.

[0133] The precursor powder preparation method and ceramic part manufacturing method proposed in this embodiment, by using the aforementioned tungsten carbide grinding balls to perform multi-stage ball milling of pure ceramic powder, can effectively improve the ball milling speed and reduce the particle size of the precursor powder obtained by ball milling. Furthermore, by comparison... Figure 2 and Figure 8 It is evident that, since the ceramic part manufacturing method proposed in this embodiment adopts the aforementioned precursor powder preparation method, compared with related technical solutions, the ceramic part manufacturing method proposed in this embodiment does not require the steps of adding solid solution components to raw materials, drying, calcination, bonding and granulation, and debinding, thereby greatly shortening the process and reducing process energy consumption and time consumption.

[0134] As another technical solution, a ceramic component is used in semiconductor process equipment and is manufactured using the ceramic component manufacturing method described above.

[0135] Specifically, the average grain size of this ceramic part is less than 900 nm.

[0136] Figure 11 and Figure 12 The microstructure and grain size distribution of yttrium oxide ceramic parts manufactured using the ceramic part manufacturing methods described above and related technical solutions are shown respectively. It is clearly evident that the yttrium oxide ceramic part in this embodiment can achieve densification, and its microstructure contains fewer pores, with a more uniform overall grain size. Furthermore, as... Figure 13 As shown, the grain size of the yttrium oxide ceramic part in this embodiment exhibits a normal distribution, and further calculations show that the average grain size is 823 nm. In contrast, the average grain size range of yttrium oxide ceramic parts obtained by related technologies is usually 10 μm to 20 μm. Obviously, the grain size of the yttrium oxide ceramic part in this embodiment can be much smaller than that of the yttrium oxide ceramic parts obtained by related technologies.

[0137] Furthermore, through multiple hardness tests, the Vickers hardness of the yttrium oxide ceramic part in this embodiment can reach 7.6 GPa or higher. In contrast, the Vickers hardness of yttrium oxide ceramic parts obtained by related technologies is typically around 6.6 GPa. Compared to existing yttrium oxide ceramic parts, the hardness of the yttrium oxide ceramic part in this embodiment is clearly increased by approximately 15%, which significantly improves the mechanical properties of the yttrium oxide ceramic part.

[0138] Furthermore, through repeated acid etching tests on cracked yttrium oxide ceramic samples, the researchers obtained the following results: Figure 14 and Figure 15 As shown in the microstructure, it is clear that the crack propagation mode of the yttrium oxide ceramic part in this embodiment is intergranular fracture rather than transgranular fracture. It can be seen that due to the reduction in grain size and the increase in the volume content of ceramic grain boundaries, crack propagation can be effectively hindered. Therefore, compared with related technologies, the yttrium oxide ceramic part in this embodiment has better fracture resistance and etching resistance.

[0139] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for making a precursor powder for use in a ceramic part manufacturing process, the method comprising: The application relates to a method for preparing a precursor powder of a ceramic piece. ​ The method comprises the following steps: obtaining raw materials; the raw materials are pure ceramic powder; ball milling the raw materials by using tungsten carbide balls to obtain primary precursor powder; wherein the ball milling process comprises a first ball milling stage and at least one second ball milling stage; the ball milling speed in the first ball milling stage is less than the ball milling speed in the second ball milling stage; 2. The method of claim 1, wherein screening the primary precursor powder to obtain the precursor powder.

3. The method of claim 2, wherein The tungsten carbide balls are multiple and comprise multiple first tungsten carbide balls and multiple second tungsten carbide balls; wherein the diameter of the first tungsten carbide balls is greater than the diameter of the second tungsten carbide balls. The step of ball milling the raw materials by using tungsten carbide balls comprises the following steps: placing the multiple first tungsten carbide balls, the multiple second tungsten carbide balls and the raw materials in a container of a ball mill; driving the container to rotate at a first rotating speed for a first time length in the first ball milling stage; driving the container to rotate at a second rotating speed for a second time length in the second ball milling stage; 4. The method of claim 1, wherein wherein the second rotating speed is greater than the first rotating speed; and the second time length is greater than the first time length.

5. The method of claim 3, wherein the precursor powder is made by a process comprising: The ball-to-powder mass ratio in the ball milling process ranges from 15:1 to 25:

1. The first rotating speed ranges from 100 r / min to 200 r / min; 6. The method of claim 3, wherein the precursor powder is made by a process comprising: The second rotating speed ranges from 900 r / min to 1500 r / min. The first time length ranges from 5 min to 10 min; 7. The method of claim 2, wherein the precursor powder is made by a process comprising: The second time length ranges from 90 min to 150 min. The diameter of the first tungsten carbide balls ranges from 5 mm to 8 mm; 8. The method of claim 7, wherein the precursor powder is made by a process comprising: The diameter of the second tungsten carbide balls ranges from 1 mm to 3 mm.

9. The method of claim 3, wherein the precursor powder is made by a process comprising: The quantity ratio of the first tungsten carbide balls to the second tungsten carbide balls ranges from 1:4 to 1:

6. The step of placing the multiple first tungsten carbide balls, the multiple second tungsten carbide balls and the raw materials in the container comprises the following steps: placing the multiple second tungsten carbide balls and the raw materials in the container; 10. The method of claim 1, wherein placing the multiple first tungsten carbide balls in the container to place the first tungsten carbide balls above the second tungsten carbide balls and the raw materials. The step of screening the primary precursor powder comprises the following steps: screening the primary precursor powder by using a first mesh to obtain secondary precursor powder passing through the first mesh; 11. A method of manufacturing a ceramic piece, characterized by, screening the secondary precursor powder by using a second mesh to obtain powder not passing through the second mesh, and taking the powder as the precursor powder; wherein the second mesh is larger than the first mesh. The application further relates to a method for manufacturing a ceramic piece. The method comprises the following steps: a precursor powder preparation step: the precursor powder is prepared by using the precursor powder preparation method in any one of claims 1-10; 12. A ceramic piece for use in a semiconductor process apparatus, characterized by, a forming step: the precursor powder is placed in a rigid mold, a specified pressure is applied to the precursor powder and maintained for a specified time length, so that a green body with a specified shape is formed; 13. The ceramic piece of claim 12, wherein, a ceramic sintering step: the green body is sintered to a ceramic state. The ceramic piece is manufactured by using the ceramic piece manufacturing method in claim 11. The average grain size of the ceramic piece is less than 900 nm.

Images