Indium cerium oxide target material and preparation method thereof

Abstract

The invention belongs to the field of target material preparation, and particularly discloses a preparation method of a multi-layer laminated indium cerium oxide target material. Comprising the following steps: (1) preparing mixed powder A from indium oxide powder and cerium oxide powder through pulping and primary granulation; (2) pre-sintering the mixed powder A, and granulating for the second time to prepare mixed powder B; (3) the mixed powder B is subjected to green body forming, specifically, a plurality of small-size target blanks are formed firstly, the multiple small-size target blanks are stacked to form a target blank whole, the target blank whole is stacked, and a formed target blank is obtained; and (4) sintering a molded target blank to obtain the indium cerium oxide target material. On the premise that the size of the target material is not influenced and the components of the target material are not changed, the target material has a multi-layer structure by firstly pressing the small-size target blank and then laminating, so that the longitudinal thermal conductivity of the target material is reduced, the heat is preferentially and transversely conducted, and the utilization rate of the target material during evaporation coating is improved.

Description

Technical Field

[0001] The invention belongs to the field of target material preparation, and specifically relates to an indium cerium oxide target material and a preparation method thereof. Background Art

[0002] Indium Tin Oxide (ITO) film has high carrier concentration, high visible light transmittance, ultraviolet absorption rate and other excellent semiconductor properties. It is widely used in screen displays, photovoltaic cells, functional glass and other fields. However, its transmittance in the near-infrared region is poor, resulting in large photoelectric conversion losses.

[0003] Existing studies have shown that the indium cerium oxide (ICO) target prepared by using cerium oxide to replace tin oxide and indium oxide for doping can effectively improve electron mobility and infrared band transmittance. However, when using traditional ICO targets for evaporation coating, the target material is easily incompletely evaporated due to the excessively fast longitudinal thermal conductivity of the target material, resulting in low utilization rate, and excessive residual waste residue after evaporation falls into and contaminates the instrument, resulting in low coating efficiency. Summary of the invention

[0004] The object of the present invention is to provide an indium cerium oxide target and a preparation method thereof to solve at least one technical problem existing in the background technology.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: A method for preparing an indium cerium oxide target comprises the following steps: (1) preparing mixed powder A by slurrying and first granulation of indium oxide powder and cerium oxide powder; (2) Mixed powder A is pre-sintered and granulated for the second time to prepare mixed powder B; (3) green-molding the mixed powder B: firstly molding a plurality of small-sized target blanks, stacking the plurality of small-sized target blanks to form a target blank as a whole, and laminating the target blank as a whole to obtain a molded target blank; (4) Sintering the formed target blank to obtain an indium cerium oxide target material.

[0006] Furthermore, the mass ratio of the indium oxide powder to the cerium oxide powder is 96-98:2-4.

[0007] Furthermore, the purity of the indium oxide powder is ≥4N and the particle size is 120-270 nm.

[0008] Furthermore, the purity of the cerium oxide powder is ≥4N and the particle size is 120-270 nm.

[0009] Furthermore, the pulping in step (1) is: (11) Pre-dispersing the cerium oxide powder, dispersant I and water, and then ball milling the mixture after uniform dispersion to obtain slurry I; (12) Indium oxide powder, dispersant II and water are added to slurry 1 for secondary pre-dispersion to obtain slurry 2.

[0010] More preferably, the dispersant I is at least one of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate, sodium hexadecylbenzene sulfonate or a polycarboxylic acid compound.

[0011] More preferably, the dispersant II is at least one of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate or sodium hexadecylbenzene sulfonate.

[0012] Further preferably, the mass of the dispersant I accounts for 2-5% of the total mass of the added cerium oxide powder, dispersant I and water.

[0013] Further preferably, the mass of the dispersant II accounts for 2-5% of the total mass of the added indium oxide powder, dispersant II and water.

[0014] Furthermore, the pre-sintered mixed powder A is mixed with a binder and then granulated for the second time.

[0015] Further preferably, the binder is one of polyvinyl alcohol, polyethylene glycol, carboxymethyl cellulose or polypropionic acid compounds.

[0016] Further preferably, the amount of the binder added is 1-3% of the mass of the mixed powder A.

[0017] Furthermore, in step (2), the mixed powder A passed through an 80-mesh sieve is pre-sintered.

[0018] Furthermore, the pre-sintered mixed powder A passed through an 80-mesh sieve was granulated for the second time.

[0019] Furthermore, in step (1), the particle size range of the mixed powder A is D50<0.5μm, D90<0.8μm.

[0020] Considering the high production efficiency, uniform particle size, good fluidity and simple operation of spray granulation, the present invention further preferably adopts spray granulation as the first granulation.

[0021] The pre-sintering of the present invention can remove organic matter in the spray granulation process on the one hand, and on the other hand, can first allow the powder to partially shrink, and the subsequent target sintering can avoid the large volume shrinkage of the powder causing the target to crack, thereby causing the target to crack during the preparation process. Further, in step (2): the pre-sintering temperature is 1200~1400℃; the pre-sintering time is 2~6h.

[0022] More preferably, the pre-sintering is performed in an oxygen atmosphere and at normal pressure.

[0023] Considering that the dry granulation process is easy to scale up, simple to operate, low in cost, uniform in particle size, and increased in bulk density, the present invention further prefers that the second granulation is dry granulation.

[0024] Furthermore, the dry granulation pressure is 30-50 kg, and the pressing time is 3-5 s.

[0025] Furthermore, in step (3): The shape and size of the cross section of the small-sized target blank are the same as the shape and size of the cross section of the formed target blank.

[0026] The thickness of each small-sized target blank varies within ±0.1 mm.

[0027] The overall height of the target blank is higher than the height of the molded target blank.

[0028] The molding pressure of small-sized target blank is 30~40kg, and the pressing time is 3~5s.

[0029] The pressure used during stacking molding is 30~50kg, and the pressing time of stacking molding is 3~5s.

[0030] Furthermore, in step (4), the sintering temperature of the molded target blank is 1200-1600° C. and the sintering time is 10-14 hours.

[0031] The invention also discloses an indium cerium oxide target material prepared by the preparation method.

[0032] Compared with the prior art, the present invention has the following beneficial effects: Under the premise of not affecting the size of the target material and changing its composition, the present invention first presses a small-sized target blank and then stacks it to make the target material have a multi-layer structure, so that the longitudinal thermal conductivity of the target material is reduced, and the heat is preferentially conducted horizontally, thereby improving the utilization rate of the target material during evaporation coating, reducing the amount of residue after evaporation, and keeping the evaporation equipment clean. To a certain extent, it can also achieve the effect of controlling the evaporation amount and thus controlling the film thickness.

[0033] The present invention adopts a lamination method to make the density of the prepared target material more uniform, thereby improving the uniformity of the evaporation coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0035] In the attached picture: Figure 1It is a schematic diagram of the overall structure of the formed target blank of the present invention.

[0036] Figure 2 It is a schematic structural diagram of the small-sized target blank of the present invention.

[0037] Figure 3 It is a schematic diagram of the stacking molding structure of the present invention. DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and carefully in combination with preferred embodiments below, but the protection scope of the present invention is not limited to the following specific embodiments.

[0039] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0040] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0041] Example 1 (1) Weigh 19.4 kg of indium oxide powder with a purity of 4N and a particle size of 120-270 nm and 0.6 kg of cerium oxide powder with a purity of 4N and a particle size of 120-270 nm.

[0042] Pour 0.6 kg of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water into a slurry barrel for pre-dispersion. The dispersion time is 1 hour. The mass of sodium dodecylbenzene sulfonate accounts for 3% of the total mass of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water. After uniform dispersion, transfer the solution to a ball mill tank. The ball mill speed is 300 r / min and the ball mill time is 20 hours to obtain slurry one.

[0043] 19.4 kg of indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water were added to the obtained slurry 1 for secondary pre-dispersion. The dispersion time was 1 hour, and the polyvinyl pyrrolidone accounted for 3% of the total mass of the indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water to obtain slurry 2.

[0044] The slurry 2 is injected into a spray drying tower in the form of a fluid for spray granulation, and then mixed and sieved to obtain an indium cerium oxide precursor, which is a mixed powder A. The indium cerium oxide precursor has a D50 of less than 0.5 μm and a D90 of less than 0.8 μm.

[0045] (2) Pre-sintering the indium cerium oxide precursor, placing it in a normal pressure sintering furnace in an oxygen atmosphere at 1300°C for 5 hours, and then taking it out after it naturally drops to room temperature.

[0046] The pre-sintered indium cerium oxide precursor was sieved with an 80-mesh sieve, and the sieved material was taken as qualified powder, and then a polyvinyl alcohol binder of 2% of the total weight of the powder was added; the powder after adding the binder was dry granulated, and the pressure used during dry granulation was 40 kg, and the pressing time was 3 seconds, to obtain a mixed powder B.

[0047] (3) If Figures 1 to 3 As shown, the obtained mixed powder B is molded to obtain a molded target blank 1. In the molding process, 8 small-sized target blanks 2 with a size of D26*5.5 mm are first pressed in a mold 3, and then the 8 small-sized target blanks 2 are stacked and laminated to obtain a molded target blank 1 with a size of D26*40 mm.

[0048] During hydraulic forming, the forming pressure of the small-size target blank 2 is 35 kg, and the pressing time of hydraulic forming is 3 s; the pressure of stacking forming is 30 kg, and the pressing time of stacking forming is 3 s.

[0049] (4) Place the prepared target blank on an alumina gasket and put it into a sintering furnace. Then, sinter it to 1200°C with oxygen and keep it at this temperature for 14 hours. After it naturally cools to room temperature, take it out to obtain the target material.

[0050] The target material produced in this embodiment was subjected to surface dust removal, and the density was measured by the Archimedean drainage method to be 4.596 g / cm 3 When the target material is used for coating, the target material can be effectively evaporated to the target substrate due to the faster lateral heat conduction and longitudinal heat conduction. By weighing the mass of the target material before and after evaporation and calculating the ratio of the two, the utilization rate of the target material is 63%.

[0051] Example 2 (1) Weigh 19.4 kg of indium oxide powder with a purity of 4N and a particle size of 120-270 nm and 0.6 kg of cerium oxide powder with a purity of 4N and a particle size of 120-270 nm.

[0052] Pour 0.6 kg of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water into a slurry barrel for pre-dispersion. The dispersion time is 1 hour. The mass of sodium dodecylbenzene sulfonate accounts for 3% of the total mass of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water. After uniform dispersion, transfer the solution to a ball mill tank. The ball mill speed is 300 r / min and the ball mill time is 20 hours to obtain slurry one.

[0053] 19.4 kg of indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water were added to the obtained slurry 1 for secondary pre-dispersion. The dispersion time was 1 hour, and the polyvinyl pyrrolidone accounted for 3% of the total mass of the indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water to obtain slurry 2.

[0054] The slurry 2 is injected into a spray drying tower in the form of a fluid for spray granulation, and then mixed and sieved to obtain an indium cerium oxide precursor, which is a mixed powder A. The indium cerium oxide precursor has a D50 of less than 0.5 μm and a D90 of less than 0.8 μm.

[0055] (2) Pre-sintering the indium cerium oxide precursor, placing it in a normal pressure sintering furnace in an oxygen atmosphere at 1300°C for 5 hours, and then taking it out after it naturally drops to room temperature.

[0056] The pre-sintered indium cerium oxide precursor was sieved with an 80-mesh sieve, and the sieved material was taken as qualified powder, and then a polyvinyl alcohol binder of 2% of the total weight of the powder was added; the powder after adding the binder was dry granulated, and the pressure used during dry granulation was 40 kg, and the pressing time was 3 seconds, to obtain a mixed powder B.

[0057] (3) The obtained mixed powder B is molded to obtain a molded target blank. In the molding process, 5 small-sized target blanks with a size of D26*8.5 mm are first pressed in a mold, and then the 5 small-sized target blanks are stacked and laminated to obtain a molded target blank with a size of D26*40 mm.

[0058] During hydraulic forming, the forming pressure of the small-size target blank is 35kg, and the pressing time of hydraulic forming is 3s; the pressure of stacking forming is 30kg, and the pressing time of stacking forming is 3s.

[0059] (4) Place the prepared target blank on an alumina gasket and put it into a sintering furnace. Then, sinter it to 1200°C with oxygen and keep it at this temperature for 14 hours. After it naturally cools to room temperature, take it out to obtain the target material.

[0060] The target material produced in this embodiment was subjected to surface dust removal, and the density was measured by the Archimedean drainage method to be 4.595 g / cm 3 When the target material is used for coating, the target material can be effectively evaporated to the target substrate due to the faster lateral heat conduction and longitudinal heat conduction. By weighing the mass of the target material before and after evaporation and calculating the ratio of the two, the utilization rate of the target material is 56%.

[0061] Example 3 (1) Weigh 19.4 kg of indium oxide powder with a purity of 4N and a particle size of 120-270 nm and 0.6 kg of cerium oxide powder with a purity of 4N and a particle size of 120-270 nm.

[0062] Pour 0.6 kg of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water into a slurry barrel for pre-dispersion. The dispersion time is 1 hour. The mass of sodium dodecylbenzene sulfonate accounts for 3% of the total mass of cerium oxide powder, sodium dodecylbenzene sulfonate and 6 kg of pure water. After uniform dispersion, transfer the solution to a ball mill tank. The ball mill speed is 300 r / min and the ball mill time is 20 hours to obtain slurry one.

[0063] 19.4 kg of indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water were added to the obtained slurry 1 for secondary pre-dispersion. The dispersion time was 1 hour, and the polyvinyl pyrrolidone accounted for 3% of the total mass of the indium oxide powder, polyvinyl pyrrolidone and 5 kg of pure water to obtain slurry 2.

[0064] The slurry 2 is injected into a spray drying tower in the form of a fluid for spray granulation, and then mixed and sieved to obtain an indium cerium oxide precursor, which is a mixed powder A. The indium cerium oxide precursor has a D50 of less than 0.5 μm and a D90 of less than 0.8 μm.

[0065] (2) Pre-sintering the indium cerium oxide precursor, placing it in a normal pressure sintering furnace in an oxygen atmosphere at 1200°C for 5 hours, and then taking it out after it naturally drops to room temperature.

[0066] The pre-sintered indium cerium oxide precursor was sieved with an 80-mesh sieve, and the sieved material was taken as qualified powder, and then a polyvinyl alcohol binder of 2% of the total weight of the powder was added; the powder after adding the binder was dry granulated, and the pressure used during dry granulation was 40 kg, and the pressing time was 3 seconds, to obtain a mixed powder B.

[0067] (3) The obtained mixed powder B is hydraulically formed to obtain a molded target blank. In the molding process, 10 small-sized target blanks with a size of D26*4.5 mm are first pressed, and then the 10 small-sized target blanks are stacked for final lamination molding to obtain a molded target blank with a size of D26*40 mm.

[0068] During hydraulic forming, the forming pressure of the small-size target blank is 35kg, and the pressing time of hydraulic forming is 3s; the pressure of stacking forming is 30kg, and the pressing time of stacking forming is 3s.

[0069] (4) Place the prepared target blank on an alumina gasket and put it into a sintering furnace. Then, sinter it to 1200°C with oxygen and keep it at this temperature for 14 hours. After it naturally cools to room temperature, take it out to obtain the target material.

[0070] The target material produced in this embodiment was subjected to surface dust removal, and the density was measured by the Archimedean drainage method to be 4.595 g / cm 3 When the target material is used for coating, the target material can be effectively evaporated to the target substrate due to the faster lateral heat conduction and longitudinal heat conduction. By weighing the mass of the target material before and after evaporation and calculating the ratio of the two, the utilization rate of the target material is 68%.

[0071] Comparative Example 1 This comparative example is basically the same as Example 1, except that in step (3), this comparative example does not involve the process of making a small-sized target blank, and directly forms a target blank with a size of D26*40 mm.

[0072] Specifically: (3) The obtained mixed powder B is subjected to hydraulic molding to obtain a molded target blank of D26*40 mm. The pressure during hydraulic molding is 30 kg and the pressing time is 3 s.

[0073] The target material produced in this embodiment was subjected to surface dust removal, and the density was measured by the Archimedean drainage method to be 4.295 g / cm 3 When the target material is used for coating, the utilization rate of the target material is 51% by weighing the mass of the target material before and after evaporation and calculating the ratio of the two.

[0074] Comparative Example 2 This comparative example is basically the same as Example 1, except that step (2) is omitted in this comparative example.

[0075] (2) Add 2% of the total mass of polyvinyl alcohol binder to the indium cerium oxide precursor; dry granulate the powder after adding the binder. The pressure used during dry granulation is 40 kg and the pressing time is 3 seconds to obtain mixed powder B.

[0076] In this comparative example, cracking occurred during the sintering process in step (4).

[0077] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. A method for preparing an indium cerium oxide target, characterized in that: The following steps are involved: (1) preparing mixed powder A by slurrying and first granulation of indium oxide powder and cerium oxide powder; (2) Mixed powder A is pre-sintered and granulated for the second time to prepare mixed powder B; (3) green-molding the mixed powder B: firstly molding a plurality of small-sized target blanks, stacking the plurality of small-sized target blanks to form a target blank as a whole, and laminating the target blank as a whole to obtain a molded target blank; (4) Sintering the formed target blank to obtain an indium cerium oxide target material.

2. The preparation method according to claim 1, characterized in that The mass ratio of the indium oxide powder to the cerium oxide powder is 96-98:2-4; The indium oxide powder has a purity of ≥4N and a particle size of 120-270 nm; The purity of the cerium oxide powder is ≥4N and the particle size is 120-270nm.

3. The preparation method according to claim 1 or 2, characterized in that: The pulping in step (1) is as follows: (11) Pre-dispersing the cerium oxide powder, dispersant I and water, and then ball milling the mixture after uniform dispersion to obtain slurry I; (12) Indium oxide powder, dispersant II and water are added to slurry 1 for secondary pre-dispersion to obtain slurry 2.

4. The preparation method according to claim 3, characterized in that: The dispersant I is at least one of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate, sodium hexadecylbenzene sulfonate or a polycarboxylic acid compound; The dispersant II is at least one of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate or sodium hexadecylbenzene sulfonate; The mass of the dispersant I accounts for 2-5% of the total mass of the added cerium oxide powder, dispersant I and water; The mass of the dispersant II accounts for 2-5% of the total mass of the added indium oxide powder, dispersant II and water.

5. The preparation method according to claim 1, characterized in that: In step (2), the pre-sintered mixed powder A is mixed with a binder and then granulated for the second time; The binder is at least one of polyvinyl alcohol, polyethylene glycol, carboxymethyl cellulose or polypropionic acid compounds; The mass of the binder is 1-3% of the mass of the mixed powder A.

6. The preparation method according to claim 1, characterized in that: In step (1): The particle size range of the mixed powder A is D50<0.5μm, D90<0.8μm; The first granulation is spray granulation.

7. The preparation method according to claim 1, characterized in that: Step (2): The pre-sintering temperature is 1200-1400°C; the pre-sintering time is 2-6 hours; The second granulation is dry granulation; The dry granulation pressure is 30-50 kg, and the pressing time is 3-5 s.

8. The preparation method according to claim 1, characterized in that: In step (3): The shape and size of the cross section of the small-sized target blank are the same as those of the formed target blank; the thickness of each small-sized target blank differs within ±0.1 mm; The molding pressure of the small-sized target blank is 30-40 kg, and the pressing time is 3-5 s; The pressure used during stacking molding is 30~50kg, and the pressing time of stacking molding is 3~5s.

9. The preparation method according to claim 1, characterized in that: In step (4), the sintering temperature of the molded target blank is 1200-1600° C. and the sintering time is 10-14 hours.

10. An indium cerium oxide target prepared by the preparation method according to any one of claims 1 to 9.

Images