Preparation method of RPD target material and RPD target material

Abstract

The invention provides a preparation method of an RPD target material and the RPD target material. The preparation method of the RPD target material comprises the steps that an ITO waste target and an ITO waste target blank serve as raw materials, ITO waste target powder and ITO waste target blank powder are prepared respectively, after the ITO waste target powder and the ITO waste target blank powder are mixed to obtain mixed powder, biscuit forming, glue discharging and sintering are carried out, the ITO waste target is a sintered ITO waste target material, the ITO waste target blank is a sintered ITO waste target material, and the ITO waste target powder and the ITO waste target blank powder are mixed to obtain the mixed powder. The ITO waste target blank is an ITO waste target material which is not sintered. The invention further provides the RPD target material.

Description

Technical Field

[0001] The invention belongs to the technical field of target materials for photovoltaic cells, and in particular relates to a preparation method of an RPD target material and the RPD target material. Background Art

[0002] The transparent conductive oxide film (TCO film) prepared by physical vapor deposition (PVD) process using indium tin oxide (ITO) target as raw material has excellent photoelectric properties and is widely used in display, solar cells, optical coating, low-emissivity glass and electrochromic fields.

[0003] A large amount of waste ITO materials will be generated during the preparation and use of ITO targets. How to use these waste materials in a green and efficient way is an urgent problem to be solved. For example, during the dry pressing and cold isostatic pressing process of ITO target blanks, a large amount of waste target blanks will often be generated due to cracking, dimensional deviation, and edge processing. On the other hand, the utilization rate of ITO targets for PVD coating is mostly 30%-80%, of which the utilization rate of planar targets is only 30%-40%, which will produce a large number of ITO residual targets. In addition, the target materials will also produce some cracks and processing scraps during the processing process, which are collectively referred to as waste targets. At present, for these waste ITO materials, most companies use high-temperature reduction to prepare indium ingots, and then prepare indium oxide through wet or dry processes. This process consumes a lot of resources and time, and the process is complicated, which greatly increases the production cost of the company.

[0004] Using high-density ITO waste targets as raw materials to prepare low-density reactive plasma deposition (RPD) targets is an energy-saving and efficient method for utilizing residual targets. RPD coating has the advantages of small substrate damage, high target utilization rate, and good film-forming performance, and is gradually used in large-scale industrial coating. For PVD coating, magnetron sputtering coating has high requirements for target density, but the RPD coating process requires that the density of the target is mostly 60±5%. This is because high-density targets are prone to cracking during the RPD coating process, and if the target density is too low, it is easy to fall off, which has a great impact on the quality of the TCO film. In the related art, CN110483033A uses indium hydroxide slurry and ITO waste targets as the main raw materials to prepare low-density ITO series RPD targets; CN115385667A uses all residual targets as raw materials to prepare RPD targets. However, these technologies have some shortcomings. On the one hand, CN110483033A needs to consume new metal indium as a raw material to prepare indium hydroxide slurry, and on the other hand, it is necessary to perform multi-step pretreatment on the waste target. The entire process is relatively complicated, and the ITO coarse powder and indium hydroxide prepared from the residual target are difficult to homogenize. Although CN115385667A uses the residual target as the raw material, it is necessary to soak the residual target powder in a hydrochloric acid solution and heat it, and then add ammonium bicarbonate to react and generate basic indium carbonate, and the neutralized powder needs to be washed several times in pure water until the chloride ions are completely removed. The whole process takes a long time, and the reaction speeds of indium and tin in hydrochloric acid and ITO are inconsistent, which will lead to poor uniformity of the chemical composition of the powder, thereby affecting the uniformity of the target material. Therefore, it is necessary to develop a new method for preparing RPD targets. Summary of the invention

[0005] The present invention aims to solve at least one of the above technical problems existing in the prior art. To this end, the present invention provides a method for preparing an RPD target material, which effectively utilizes a large amount of waste generated during the preparation and use of the ITO target material, and is conducive to large-scale industrial application.

[0006] The invention also provides a RPD target material.

[0007] The first aspect of the present invention provides a method for preparing an RPD target material, the preparation method comprising: using ITO waste target and ITO waste target blank as raw materials to prepare ITO waste target powder and ITO waste target blank powder respectively, mixing the ITO waste target powder and ITO waste target blank powder to obtain a mixed powder, and then performing the steps of blank forming, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0008] A technical solution in the method for preparing the RPD target of the present invention has at least the following beneficial effects:

[0009] A large amount of waste ITO materials will be generated during the preparation and use of ITO targets. The waste ITO materials include the target materials remaining after use, as well as some that have not been used. For example, the target materials obtained by sintering need to be polished and cut by machine tools to reach the shipping size specifications, and cracks and leftover scraps will appear during the processing. There are also some processed materials that have not been sintered in the target preparation process, but have cracked during the molding process, or are generated due to size reasons.

[0010] The hardness and strength of the sintered ITO waste target are relatively large, and it is difficult to grind evenly to obtain finer powder. However, the strength and hardness of the unsintered ITO waste target are relatively low, and its raw material is nano-scale ITO powder, which is only formed under the action of pressure and organic binder. Therefore, after removing the organic reagent, ITO powder with smaller particle size can be obtained after a short time of ball milling, and these powders are more active. The present invention uses coarse particles of ITO waste target powder prepared from sintered ITO waste target as the main raw material to form the matrix material of the low-density RPD target, and at the same time uses small-particle-size ITO waste target blank powder prepared from unsintered ITO waste target as the bonding phase in the sintering process of the RPD target. The RPD target can be prepared through a simple process, and a large amount of waste generated during the preparation and use of the ITO target is effectively utilized. Not only is the waste material generated during the production and use of the target material efficiently utilized, but also the processes of high-temperature reduction and purification of indium ingots, wet or dry preparation of indium oxide powder, etc. are reduced, the production efficiency is improved, and the production cost of the RPD target is greatly reduced. The whole process is simple and is conducive to large-scale industrial application.

[0011] According to some embodiments of the present invention, the method of preparing ITO waste target powder and ITO waste target blank powder respectively using ITO waste target and ITO waste target blank as raw materials includes ball milling.

[0012] According to some embodiments of the present invention, a method for preparing ITO waste target powder using ITO waste target as raw material includes:

[0013] Wash and dry the ITO waste target, then crush it through a 200-300 mesh sieve. The resulting ITO waste target powder can be used as the main raw material for the RPD target (it has been sintered at high temperature and the powder activity is poor).

[0014] According to some embodiments of the present invention, a method for preparing ITO waste target blank powder using ITO waste target blank as raw material includes:

[0015] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose of which is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h to remove the organic reagent, and then ball-milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not undergone high-temperature treatment, ITO waste target blank powder with smaller particle size can be obtained after ball milling for 3h~6h (since it has not been sintered, the powder activity is relatively large).

[0016] According to some embodiments of the present invention, the particle size D90 of the ITO waste target powder is less than 65 μm.

[0017] According to some embodiments of the present invention, the particle size D90 of the ITO waste target powder is less than 1.0 μm.

[0018] According to some embodiments of the present invention, in the mixed powder, the content of the ITO waste target powder is 70wt% to 95wt%, and the content of the ITO waste target blank powder is 5wt% to 30wt%.

[0019] According to some embodiments of the present invention, the mixed powder making method includes: mixing the ITO waste target powder and the ITO waste target blank powder, adding a pore-forming agent, a dispersant and water for ball milling, adding a binder to the obtained slurry, stirring, and spray granulating to obtain spherical powder.

[0020] According to some embodiments of the present invention, the pore former comprises at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3.

[0021] According to some embodiments of the present invention, the pore former is added in an amount of 2 wt % to 12 wt % of the mixed powder.

[0022] According to some embodiments of the invention, the dispersant comprises polyvinylpyrrolidone.

[0023] According to some embodiments of the present invention, the dispersant is added in an amount of 0.5 wt % to 1.5 wt % of the mixed powder.

[0024] According to some embodiments of the present invention, the ball milling time is 2 h to 5 h.

[0025] According to some embodiments of the invention, the binder comprises PVA.

[0026] According to some embodiments of the present invention, the added amount of the binder is 0.5 wt % to 2.0 wt % of the mass of the slurry.

[0027] According to some embodiments of the present invention, the stirring speed is 150 rpm to 300 rpm.

[0028] According to some embodiments of the present invention, the stirring time is 1 h to 3 h.

[0029] According to some embodiments of the present invention, the green billet forming pressure is 20 MPa to 50 MPa.

[0030] According to some embodiments of the present invention, the steps of debinding and sintering include: heating the green blank obtained by forming the green blank to 600℃~800℃ at a rate of 0.5℃ / min~3℃ / min, keeping it warm for 2h~6h, and continuing to heat it to 1200℃~1400℃ at a rate of 0.5℃ / min~3℃ / min, and at the same time, introducing oxygen at a rate of 5L / min~30L / min during the whole process of debinding and sintering, and keeping it warm at 1200℃~1400℃ for 5h~16h, and stopping the oxygen supply after the end of the insulation and cooling it to room temperature at a rate of 0.5℃ / min~3℃ / min to obtain the RPD target. It should be noted that oxygen is only introduced in the second stage, that is, oxygen is introduced after the insulation at 600℃~800℃ is completed, and oxygen supply is stopped after the insulation at 1200℃~1400℃ is completed.

[0031] The second aspect of the present invention provides an RPD target material prepared by the preparation method of the first aspect of the present invention.

[0032] One of the technical solutions of the present invention regarding the RPD target has at least the following beneficial effects:

[0033] Efficient utilization of waste materials: By utilizing the waste materials generated during the preparation and use of ITO targets (including sintered ITO waste targets and unsintered ITO waste targets), the utilization rate of resources is significantly improved and material waste is reduced.

[0034] Reduce production costs: Using waste materials instead of new raw materials reduces complex and expensive production steps such as high-temperature reduction and purification of indium ingots and wet or dry preparation of indium oxide powder, thereby reducing the production cost of RPD targets.

[0035] Simplified process flow: The entire preparation process is simple. By mixing ITO waste materials with different characteristics and then performing molding, debinding and sintering, RPD targets can be quickly prepared. This simplified process is conducive to large-scale industrial production.

[0036] Optimization of material properties: By using ITO waste with different particle sizes and properties, the prepared RPD target material has high hardness, high strength and good adhesion, and the density and performance of the final product are optimized.

[0037] Environmental benefits: It reduces the steps of high-temperature reduction and chemical treatment, reduces energy consumption and the emission of harmful substances, and plays a positive role in environmental protection.

[0038] According to some embodiments of the present invention, the density of the RPD target is 55% to 65%.

[0039] According to some embodiments of the present invention, the density of the RPD target is measured by the Archimedean drainage method. DETAILED DESCRIPTION

[0040] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0041] In the first aspect, some embodiments of the present invention provide a method for preparing an RPD target material, the preparation method comprising: using ITO waste target and ITO waste target blank as raw materials to prepare ITO waste target powder and ITO waste target blank powder, respectively, mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder, and then performing the steps of blank forming, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0042] It is understandable that a large amount of waste ITO materials will be generated during the preparation and use of ITO target materials. The waste ITO materials include the target materials remaining after the use of the target materials, as well as some that have not been used. For example, the target materials obtained by sintering need to be polished and cut by machine tools to reach the shipping size specifications, and cracks and leftover scraps will occur during the processing process. There are also some processed materials that have not been sintered in the target preparation process, but have cracked during the molding process, or are generated due to size reasons.

[0043] It should be noted that the hardness and strength of the sintered ITO waste target are relatively large, and it is difficult to grind evenly to obtain finer powder. The strength and hardness of the unsintered ITO waste target are relatively low, and its raw material is nano-scale ITO powder, which is only formed under the action of pressure and organic binder. Therefore, after removing the organic reagent, ITO powder with smaller particle size can be obtained after a short time of ball milling, and these powders are more active. The present invention uses coarse particles of ITO waste target powder prepared from sintered ITO waste target as the main raw material to form the matrix material of the low-density RPD target, and at the same time uses small-particle-size ITO waste target blank powder prepared from unsintered ITO waste target as the bonding phase in the sintering process of the RPD target. The RPD target can be prepared through a simple process, and a large amount of waste generated during the preparation and use of the ITO target is effectively utilized. Not only is the waste material generated during the production and use of the target material efficiently utilized, but also the processes such as high-temperature reduction and purification of indium ingots, wet or dry preparation of indium oxide powder, etc. are reduced, the production efficiency is improved, and the production cost of the RPD target is greatly reduced. The whole process is simple and is conducive to large-scale industrial application.

[0044] In combination with the first aspect, in some embodiments of the present invention, the method of preparing ITO waste target powder and ITO waste target blank powder respectively using ITO waste target and ITO waste target blank as raw materials includes ball milling.

[0045] In combination with the first aspect, in some embodiments of the present invention, a method for preparing ITO waste target powder using ITO waste target as raw material includes:

[0046] Wash and dry the ITO waste target, then crush it through a 200-300 mesh sieve. The resulting ITO waste target powder can be used as the main raw material for the RPD target (it has been sintered at high temperature and the powder activity is poor).

[0047] In combination with the first aspect, in some embodiments of the present invention, a method for preparing ITO waste target blank powder using ITO waste target blank as raw material includes:

[0048] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose of which is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h to remove the organic reagent, and then ball-milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not undergone high-temperature treatment, ITO waste target blank powder with smaller particle size can be obtained after ball milling for 3h~6h (since it has not been sintered, the powder activity is relatively large).

[0049] In combination with the first aspect, in some embodiments of the present invention, the particle size D90 of the ITO waste target powder is less than 65 μm.

[0050] In combination with the first aspect, in some embodiments of the present invention, the particle size D90 of the ITO waste target blank powder is less than 1.0 μm.

[0051] In combination with the first aspect, in some embodiments of the present invention, in the mixed powder, the content of ITO waste target powder is 70wt% to 95wt%, and the content of ITO waste target blank powder is 5wt% to 30wt%.

[0052] In combination with the first aspect, in some embodiments of the present invention, the mixed powder making method includes: mixing ITO waste target powder and ITO waste target blank powder, adding a pore-forming agent, a dispersant and water for ball milling, adding a binder to the obtained slurry, stirring, and spray granulating to obtain spherical powder.

[0053] In combination with the first aspect, in some embodiments of the present invention, the pore-forming agent includes at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3.

[0054] In combination with the first aspect, in some embodiments of the present invention, the amount of the pore former added is 2 wt % to 12 wt % of the mixed powder.

[0055] In combination with the first aspect, in some embodiments of the present invention, the dispersant includes polyvinylpyrrolidone.

[0056] In combination with the first aspect, in some embodiments of the present invention, the added amount of the dispersant is 0.5wt% to 1.5wt% of the mixed powder.

[0057] In combination with the first aspect, in some embodiments of the present invention, the ball milling time is 2 hours to 5 hours.

[0058] In combination with the first aspect, in some embodiments of the present invention, the adhesive includes PVA.

[0059] In combination with the first aspect, in some embodiments of the present invention, the amount of binder added is 0.5wt% to 2.0wt% of the slurry mass.

[0060] In combination with the first aspect, in some embodiments of the present invention, the stirring speed is 150 rpm to 300 rpm.

[0061] In combination with the first aspect, in some embodiments of the present invention, the stirring time is 1 hour to 3 hours.

[0062] In combination with the first aspect, in some embodiments of the present invention, the pressure of blank forming is 20 MPa to 50 MPa.

[0063] In combination with the first aspect, in some embodiments of the present invention, the steps of debinding and sintering include: heating the blank obtained by blank molding to 600℃~800℃ at a rate of 0.5℃ / min~3℃ / min, keeping it warm for 2h~6h, and continuing to heat it to 1200℃~1400℃ at a rate of 0.5℃ / min~3℃ / min, and at the same time, introducing oxygen at a rate of 5L / min~30L / min during the whole process of debinding and sintering, and keeping it warm at 1200℃~1400℃ for 5h~16h, and stopping the oxygen supply after the insulation is completed and cooling to room temperature at a rate of 0.5℃ / min~3℃ / min to obtain the RPD target. It should be noted that oxygen is only introduced in the second stage, that is, oxygen is introduced after the insulation at 600℃~800℃ is completed, and oxygen supply is stopped after the insulation at 1200℃~1400℃ is completed.

[0064] In the first stage, the temperature is raised to 600℃~800℃ at a rate of 0.5℃ / min~3℃ / min to slowly remove water vapor and organic reagents in the target blank. The purpose of heat preservation is to further remove the added organic reagents (dispersant and binder, etc.), that is, debinding.

[0065] In the second stage, the temperature is raised to 1200℃~1400℃ at a rate of 0.5℃ / min~3℃ / min to the sintering temperature. In order to avoid large temperature differences between the inner and outer surfaces of the target, which may cause deformation and cracking, the heating rate is relatively slow.

[0066] During the whole process of debinding and sintering, oxygen is introduced at a rate of 5L / min to 30L / min. This means that oxygen is introduced starting from the second stage and stopped after the third stage. On the one hand, oxygen introduction can promote sintering; on the other hand, at high temperatures, indium oxide is easily decomposed into low-oxygen compounds and oxygen, and introducing oxygen can inhibit this reaction.

[0067] The third stage is to keep the temperature at 1200℃~1400℃ for 5h~16h to promote sintering and make the target material have a certain strength.

[0068] The fourth stage is to cool down to room temperature at a speed of 0.5℃ / min to 3℃ / min because of natural cooling, which has a very fast cooling speed, especially in the high temperature stage, which can reach a cooling speed of several tens of ℃ / min. This slower cooling speed is set to prevent the temperature from cooling too fast, which will cause a large temperature difference between the inside and outside of the target, resulting in more thermal stress, and the risk of target material breaking and lower strength; secondly, it is to protect the sintering equipment. Too fast cooling speed will cause great damage to its heating rod and furnace, so this slower cooling speed is set.

[0069] In a second aspect, in some embodiments of the present invention, there is provided an RPD target material prepared by the preparation method of the first aspect of the present invention.

[0070] It can be understood that the RPD target prepared by the preparation method of the first aspect of the present invention has the following beneficial effects:

[0071] Efficient utilization of waste materials: By utilizing the waste materials generated during the preparation and use of ITO targets (including sintered ITO waste targets and unsintered ITO waste targets), the utilization rate of resources is significantly improved and material waste is reduced.

[0072] Reduce production costs: Using waste materials instead of new raw materials reduces complex and expensive production steps such as high-temperature reduction and purification of indium ingots and wet or dry preparation of indium oxide powder, thereby reducing the production cost of RPD targets.

[0073] Simplified process flow: The entire preparation process is simple. By mixing ITO waste materials with different characteristics and then performing molding, debinding and sintering, RPD targets can be quickly prepared. This simplified process is conducive to large-scale industrial production.

[0074] Optimization of material properties: By using ITO waste with different particle sizes and properties, the prepared RPD target material has high hardness, high strength and good adhesion, and the density and performance of the final product are optimized.

[0075] Environmental benefits: It reduces the steps of high-temperature reduction and chemical treatment, reduces energy consumption and the emission of harmful substances, and plays a positive role in environmental protection.

[0076] In combination with the second aspect, in some embodiments of the present invention, the density of the RPD target is 55% to 65%.

[0077] In combination with the second aspect, in some embodiments of the present invention, the density of the RPD target is measured by the Archimedean drainage method.

[0078] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0079] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0080] Unless otherwise specified, "room temperature" in the present invention means 25°C±5°C.

[0081] Unless otherwise specified, "about" in the present invention means that the allowable error is within ±2%.

[0082] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0083] Example 1

[0084] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0085] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0086] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0087] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0088] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0089] In the mixed powder, the content of ITO waste target powder is 95wt%, and the content of ITO waste target blank powder is 5wt%.

[0090] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0091] The pore former is specifically starch.

[0092] The amount of pore former added was 2 wt % of the mixed powder.

[0093] The dispersant is polyvinylpyrrolidone.

[0094] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0095] The ball milling time was 3 h.

[0096] The binder is PVA.

[0097] The amount of binder added was 1.0 wt% of the slurry mass.

[0098] The stirring speed was 200 rpm.

[0099] The stirring time is 2h.

[0100] The pressure of green billet molding is 30Mpa.

[0101] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1400°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1400°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0102] Example 2

[0103] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0104] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0105] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0106] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0107] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0108] In the mixed powder, the content of ITO waste target powder is 90wt%, and the content of ITO waste target blank powder is 10wt%.

[0109] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0110] The pore former is specifically starch (at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3).

[0111] The amount of pore former added was 3.5 wt % of the mixed powder.

[0112] The dispersant is polyvinylpyrrolidone.

[0113] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0114] The ball milling time was 3 h.

[0115] The binder is PVA.

[0116] The amount of binder added was 1.0 wt% of the slurry mass.

[0117] The stirring speed is 200 rad / min.

[0118] The stirring time is 2h.

[0119] The pressure of green billet molding is 30Mpa.

[0120] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1350°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1350°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0121] Example 3

[0122] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0123] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0124] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0125] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0126] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0127] In the mixed powder, the content of ITO waste target powder is 85wt%, and the content of ITO waste target blank powder is 15wt%.

[0128] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0129] The pore former is specifically starch (at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3).

[0130] The amount of pore former added was 5 wt % of the mixed powder.

[0131] The dispersant is polyvinylpyrrolidone.

[0132] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0133] The ball milling time was 3 h.

[0134] The binder is PVA.

[0135] The amount of binder added was 1.0 wt% of the slurry mass.

[0136] The stirring speed is 200 rad / min.

[0137] The stirring time is 2h.

[0138] The pressure of green billet molding is 30Mpa.

[0139] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1330°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1330°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0140] Example 4

[0141] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0142] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0143] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0144] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0145] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0146] In the mixed powder, the content of ITO waste target powder is 80wt%, and the content of ITO waste target blank powder is 20wt%.

[0147] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0148] The pore former is specifically starch (at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3).

[0149] The amount of pore former added was 7 wt % of the mixed powder.

[0150] The dispersant is polyvinylpyrrolidone.

[0151] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0152] The ball milling time was 3 h.

[0153] The binder is PVA.

[0154] The amount of binder added was 1.0 wt% of the slurry mass.

[0155] The stirring speed is 200 rad / min.

[0156] The stirring time is 2h.

[0157] The pressure of green billet molding is 30Mpa.

[0158] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1300°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1300°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0159] Example 5

[0160] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0161] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0162] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0163] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0164] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0165] In the mixed powder, the content of ITO waste target powder is 75wt%, and the content of ITO waste target blank powder is 25wt%.

[0166] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0167] The pore former is specifically starch (at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3).

[0168] The amount of pore former added was 9 wt % of the mixed powder.

[0169] The dispersant is polyvinylpyrrolidone.

[0170] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0171] The ball milling time was 3 h.

[0172] The binder is PVA.

[0173] The amount of binder added was 1.0 wt% of the slurry mass.

[0174] The stirring speed is 200 rad / min.

[0175] The stirring time is 2h.

[0176] The pressure of green billet molding is 30Mpa.

[0177] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1270°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1270°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0178] Example 6

[0179] A method for preparing an RPD target material comprises the following steps: using an ITO waste target and an ITO waste target blank as raw materials to prepare an ITO waste target powder and an ITO waste target blank powder respectively; mixing the ITO waste target powder and the ITO waste target blank powder to obtain a mixed powder; and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste target is a sintered ITO waste target material, and the ITO waste target blank is an unsintered ITO waste target material.

[0180] The method for preparing ITO waste target powder using ITO waste target as raw material is as follows:

[0181] Wash the ITO waste target, dry it, and then crush it through a 250-mesh screen to obtain the ITO waste target powder, which can be used as the main raw material of the RPD target (it has been sintered at high temperature and the powder activity is poor). The particle size D90 of the ITO waste target powder is less than 65 μm.

[0182] The method for preparing ITO waste target blank powder using ITO waste target blank as raw material is as follows:

[0183] The waste target blank with the same composition as the ITO waste target (for example, if ITO is doped with 90 / 10 target material, the waste target blank also uses 90 / 10, the purpose is to ensure the high uniformity of the chemical composition of the mixed powder) is kept at 600℃~800℃ for 3h~6h, the organic reagent is removed, and then ball milled and sieved. Since the waste target blank raw material is nano-scale ITO powder and the whole process has not been subjected to high temperature treatment, after ball milling for 3h~6h, ITO waste target blank powder with smaller particle size can be obtained (because it has not been sintered, the powder activity is relatively large). The particle size D90 of ITO waste target blank powder is less than 1.0μm.

[0184] In the mixed powder, the content of ITO waste target powder is 70wt%, and the content of ITO waste target blank powder is 30wt%.

[0185] The mixed powder making method is: after mixing ITO waste target powder and ITO waste target blank powder, adding pore former, dispersant and water for ball milling, adding binder to the obtained slurry for stirring, and spray granulating to obtain spherical powder.

[0186] The pore former is specifically starch (at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3).

[0187] The amount of pore former added was 12 wt % of the mixed powder.

[0188] The dispersant is polyvinylpyrrolidone.

[0189] The amount of dispersant added was 1.0 wt % of the mixed powder.

[0190] The ball milling time was 3 h.

[0191] The binder is PVA.

[0192] The amount of binder added was 1.0 wt% of the slurry mass.

[0193] The stirring speed is 200 rad / min.

[0194] The stirring time is 2h.

[0195] The pressure of green billet molding is 30Mpa.

[0196] The steps of debinding and sintering are as follows: the green billet obtained by green billet molding is heated to 700°C at a rate of 0.8°C / min, kept warm for 3 hours, and then continued to be heated to 1230°C at a rate of 1.5°C / min. At the same time, oxygen is introduced at a rate of 20L / min at the beginning of the heating process, and kept warm at 1230°C for 8 hours. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 2°C / min to obtain the RPD target.

[0197] The RPD targets obtained in Examples 1 to 6 were measured for target density by the Archimedean drainage method, and at least 5 samples were tested in each group to calculate the final average value. The results are shown in Table 1.

[0198] Table 1

[0199]

[0200]

[0201] As shown in Table 1, the present invention uses waste targets and waste target blanks as raw materials, adds a certain amount of pore-forming agent, and prepares targets with a density of 58.1-61.8%, which meets the technical requirements of RPD targets. Compared with the existing technology, the present invention efficiently utilizes the waste materials generated in the production of target materials, which not only reduces the processes of high-temperature reduction and purification of indium ingots, wet or dry preparation of indium oxide powder, etc., improves production efficiency, but also greatly reduces the production cost of RPD targets.

[0202] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for preparing a RPD target, characterized in that: The preparation method comprises: using ITO waste targets and ITO waste target blanks as raw materials to prepare ITO waste target powder and ITO waste target blank powder respectively, mixing the ITO waste target powder and ITO waste target blank powder to obtain mixed powder, and then performing the steps of green blank molding, debinding and sintering, wherein the ITO waste targets are sintered ITO waste target materials, and the ITO waste target blanks are unsintered ITO waste target materials.

2. The preparation method according to claim 1, characterized in that: The particle size D90 of the ITO waste target powder is less than 65 μm.

3. The preparation method according to claim 1, characterized in that: The particle size D90 of the ITO waste target powder is less than 1.0 μm.

4. The preparation method according to any one of claims 1 to 3, characterized in that In the mixed powder, the content of the ITO waste target powder is 70wt% to 95wt%, and the content of the ITO waste target blank powder is 5wt% to 30wt%.

5. The preparation method according to any one of claims 1 to 3, characterized in that: The preparation method of the mixed powder comprises: mixing the ITO waste target powder and the ITO waste target blank powder, adding a pore former, a dispersant and water for ball milling, adding a binder to the obtained slurry for stirring, and spraying granulation to obtain spherical powder.

6. The preparation method according to claim 5, characterized in that: The pore-forming agent includes at least one of carbon powder, starch, carboxymethyl cellulose and NH4HCO3; and / or, the amount of the pore-forming agent added is 2wt% to 12wt% of the mixed powder; and / or, the dispersant includes polyvinylpyrrolidone; and / or, the amount of the dispersant added is 0.5wt% to 1.5wt% of the mixed powder; and / or, the ball milling time is 2h to 5h; and / or, the binder includes PVA; and / or, the amount of the binder added is 0.5wt% to 2.0wt% of the slurry mass; and / or, the stirring speed is 150rpm to 300rpm; and / or, the stirring time is 1h to 3h.

7. The preparation method according to any one of claims 1 to 3, characterized in that The pressure of the green billet molding is 20Mpa-50Mpa.

8. The preparation method according to any one of claims 1 to 3, characterized in that: The debinding and sintering steps include: heating the blank obtained by forming the blank to 600°C-800°C at a rate of 0.5°C / min-3°C / min, keeping the temperature for 2h-6h, and continuing to heat the blank to 1200°C-1400°C at a rate of 0.5°C / min-3°C / min, while introducing oxygen at a rate of 5L / min-30L / min during the whole process of debinding and sintering, and keeping the temperature at 1200°C-1400°C for 5h-16h. After the insulation is completed, the oxygen supply is stopped and the temperature is cooled to room temperature at a rate of 0.5°C / min-3°C / min to obtain an RPD target.

9. A RPD target, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. The RPD target according to claim 9, characterized in that: The density of the RPD target material is 55% to 65%.

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