KR101446614B1 - ITO granular power and cylindrical molded-object of ITO target having the same - Google Patents

Abstract

An ITO granulated powder capable of providing a high quality ITO thin film and a cylindrical ITO target shaped body including the same are provided. It is preferable that the ITO granulated powder includes an ITO fine powder and an organic binder, the average particle diameter of the ITO granulated powder is about 2 to 100 mu m, and the flowability is about 50 to 80 g / sec.

Granule powder, flowability, filling rate, forming density

Description

TECHNICAL FIELD [0001] The present invention relates to an ITO granular powder and a cylindrical ITO target molded body including the ITO granular powder and an ITO target having the same.

1 is a flowchart illustrating a method of manufacturing an ITO powder according to an embodiment of the present invention.

2 is a schematic cross-sectional view of an ITO slurry drying apparatus according to an embodiment of the present invention.

3 is a flowchart of a method of manufacturing an ITO target molded article according to an embodiment of the present invention.

4 is a schematic cross-sectional view of a mold for manufacturing an ITO target molded article according to an embodiment of the present invention.

5 is a schematic cross-sectional view of a cold isostatic apparatus for manufacturing an ITO target shaped body according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

100: ITO slurry dryer

200: mold for manufacturing ITO target molded article

300: Cold isostatic device for manufacturing ITO target shaped body

TECHNICAL FIELD The present invention relates to an ITO granular powder and a cylindrical ITO target molded article comprising the same, and more particularly, to an ITO granule powder and a cylindrical ITO target molded article which can provide a high quality ITO thin film.

Indium Tin Oxide (ITO) is a material used as a raw material for an ITO electrode included in a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED) display, a field emission display (FED) The ITO electrode is suitable for use as a transparent electrode for a display because of its excellent conductivity and transparency to a wavelength in a visible light region.

The ITO electrode can be manufactured by forming an ITO thin film on the surface of an insulating substrate such as a glass substrate. The ITO thin film may be formed by a chemical method such as spray pyrolysis, chemical vapor deposition (CVD), or a physical method such as an electron beam deposition method or a sputtering deposition method.

Sputtering deposition, which is one of the methods of forming ITO thin films, is a method in which molecules or atoms generated by impinging a plasma gas on an ITO target, which is a raw material of ITO thin film, are deposited on an insulating substrate under a pressure lower than normal pressure.

In order to form a high quality ITO thin film by the sputtering deposition method, the density of the ITO target must be very high. Examples of methods for manufacturing such a high density ITO target include a slip casting method, an extrusion forming method, a pressing method, a cold isostatic pressure compression molding method.

These methods for the production of high density ITO targets generally include the steps of making an ITO molded body using ITO powder having a certain size and composition and sintering the ITO molded body.

On the other hand, when the molding density of the ITO molded body is low or the molding density is not uniform, a crack may be generated in the process of sintering the ITO molded body. Also, when the ITO formed body having a low molding density is sintered and used as an ITO target, there is a problem that it is difficult to form a high quality ITO thin film such as a nodule during deposition using a sputtering deposition method.

Disclosure of Invention Technical Problem [8] The present invention provides an ITO granule powder capable of providing a high quality ITO thin film.

Another object of the present invention is to provide a cylindrical ITO target molded article made of such ITO granular powder.

The technical objects of the present invention are not limited to the technical matters mentioned above, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an ITO granule powder comprising ITO fine powder and an organic binder. Here, the average particle size of the ITO granule powder is about 2 to 100 mu m, and the flow property is preferably about 50 to 80 g / sec.

According to another aspect of the present invention, there is provided a cylindrical ITO target molded article comprising the ITO granule powder.

Other specific details of the invention are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a method of manufacturing an ITO granule powder and a method of manufacturing an ITO target molded article according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flowchart illustrating a method of manufacturing an ITO granule powder according to an embodiment of the present invention.

Referring to FIG. 1, an ITO granule powder according to an exemplary embodiment of the present invention includes an ITO slurry including an ITO fine powder and an organic binder (S100) and an ITO slurry (S110) And forming a powder (S120).

First, an ITO slurry containing an ITO fine powder and an organic binder is prepared (S100).

The ITO fine powder may be a fine powder having indium oxide and tin oxide at a constant weight ratio and having a constant average particle size. For example, ITO fine powder having a weight ratio of indium oxide and tin oxide of about 9 to 1 and an average particle diameter of about 10 nm to 500 nm can be used. However, the present invention is not limited thereto.

The organic binder may be an organic polymer including functional groups such as -OH, -NH ₂ , and -NHR. For example, PVB (Poly Vinyl Butyl) may be used. The organic binder binds the ITO fine powders together to maintain the shape of the granular powder having a larger particle size. The granular powder will be described later.

Meanwhile, the ITO slurry can be prepared, for example, by adding ITO slurry in which distilled water, ITO fine powder, and organic binder are added at a predetermined weight ratio into a container of a certain size and stirring for a predetermined time.

The concentration of the ITO slurry can be variously changed by adjusting the application amount of ITO fine powder, organic binder, etc., so that the average particle size of the ITO granule powder can be variously adjusted.

Then, the ITO slurry is dried (S110) to form an ITO granule powder (S130).

2 is a schematic cross-sectional view of an ITO slurry drying apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the ITO slurry is injected into the drying oven 120 at a constant supply pressure along arrow directions of the slurry supply pipe 110.

The ITO slurry can then be sprayed at the distal end of the slurry feed tube 110 and dried in a drying oven 120 that can maintain a constant temperature (e.g., about 120-200 [deg.] C). That is, the ITO slurry 111 to be sprayed is dried in the drying oven 120, and the distilled water used in the production of the ITO slurry is evaporated, and the ITO fine powder containing the organic binder and other materials has a particle size of 탆 scale It has the form of powder. Such an organic binder acts so that the ITO fine powders can maintain the shape (for example, a shape similar to a rectangular parallelepiped shape) of the ITO granular powder having a predetermined size and shape.

Thereafter, the ITO granular powder 131 dried and formed in the drying oven 120 is collected in the powder collecting container 130 by gravity.

In this manner, the ITO fine powder having a particle size of nm scale can be produced in the form of an ITO granule powder 131 having an average particle size of a mu m scale.

Meanwhile, the average particle diameter of the ITO granule powder 131 can be variously adjusted by adjusting the concentration of the ITO slurry, the supply pressure of the ITO slurry in the slurry supply pipe 110, and the drying temperature in the drying oven 120.

In the present invention, the ITO granule powder is produced so that the average particle size thereof is a constant value within a range of about 2 탆 to 100 탆. When the average particle diameter of the ITO granule powder is less than about 2 탆, the flowability is poor and the molding density of the ITO molded article may become uneven. When the average particle diameter of the ITO granule powder exceeds about 100 탆, No difference will appear.

The ITO granulated powder has excellent flowability as compared with the ITO fine powder, and can be uniformly filled in the filling part of the mold for manufacturing the ITO molded body, and the ITO molded body having a more uniform molding density can be manufactured. Here, the flowability (unit: g / sec) is a standard value measured by the ASTM standard, and indicates the degree of gravity flow of ITO powder along a tube of a container having a certain standard. The mold for manufacturing the ITO molded body will be described later.

In the present invention, the ITO granulated powder is prepared so as to have flowability of about 50 g / sec to 80 g / sec. More preferably, the ITO granulated powder is prepared to have a flowability of about 60 to 70 g / sec. If the flowability of the ITO granulated powder is less than about 50 g / sec, the powder may not be uniformly filled in the entirety of the filled part of the mold for manufacturing the ITO formed body, resulting in nonuniform molding density of the final ITO formed body. In addition, when the flowability exceeds about 80 g / sec, there is no great difference in the degree to which the powder is evenly filled in the whole charged portion of the mold.

In one embodiment of the present invention, ITO powder forming a granular powder group having an average particle size of different sizes can be produced. That is, the ITO powder is prepared by repeating the above-described ITO slurry preparation step (S100) and the ITO slurry drying step (S110) so as to produce granular powders having different average particle diameters, and each granular powder has a constant weight ratio And can be produced by uniform mixing. At this time, it is possible to change the concentration of the ITO slurry, the supply pressure of the ITO slurry, and the drying temperature so as to have an average particle size of different sizes.

For example, when preparing an ITO granular powder containing granular powder having three average particle sizes, the first granular powder is about 50-70 μm, the second granular powder is about 15-30 μm, the third granular powder The ITO slurry preparation step (S100) and the ITO slurry drying step (S110) may be repeatedly performed individually so as to have an average particle size of about 5 - 10 mu m.

Thereafter, the first granular powder, the second granular powder and the third granular powder were mixed for about 1 hour in a predetermined weight ratio (for example, about 10 - 25 wt%, 25 - 40 wt%, and 40 - 55 wt% A granular powder can be produced.

When the ITO granulated powder containing the granular powder having the average particle size of different sizes is filled in the filling part of the mold for manufacturing the ITO molded body, the charging rate can be increased as compared with the case of using ITO granulated powder having a single average particle size, The forming density of the ITO molded body can be increased. Here, the filling rate means that the volume occupied by the powder per unit volume of the packed portion is expressed as a percentage.

4 and 5, a mold for manufacturing an ITO target molded article and a cold isostatic pressing apparatus according to an embodiment of the present invention will be described

4 is a schematic cross-sectional view of a mold for manufacturing an ITO target molded article according to an embodiment of the present invention.

4, a mold 200 for manufacturing an ITO target molded body according to an exemplary embodiment of the present invention includes a lower support 210, an inner core 220, an outer wall 230, a charger 240, ).

For manufacturing the hollow cylindrical ITO formed body, the inner core portion 220 has a cylindrical structure. The diameter of the inner core portion 220 may be designed differently according to the standard of the ITO formed body to be desired. The inner core portion 220 is preferably made of a high strength material so as to withstand cold isostatic pressure.

The outer wall portion 230 has a hollow cylindrical structure arranged at a predetermined distance from the outer periphery of the inner core portion 220. The spacing space between the outer wall portion 230 and the inner core portion 220 constitutes the charging portion 240. The ITO granular powder is inserted into the charging part 240 and charged. The cold water is uniformly applied to the ITO granule powder while the cold water is not infiltrated into the ITO granule powder when the cold isostatic pressure is applied to the mold 200 for manufacturing the ITO target shaped body and the cold outer water pressure is uniformly applied to the ITO granule powder, The portion 230 is preferably made of a hydrophobic rubber material having high durability.

The lower support part 210 has a disc shape as a whole and the coupling part 212 is formed in the lower support part 220 so that the lower support part 220 can be inserted and fixed to the charging part 240 between the inner core part 220 and the outer wall part 230 .

The lower support part 210 may be made of a high strength material to withstand the cold water pressure, and may be made of substantially the same material as the internal core part 220.

The upper support portion 250 may have substantially the same shape as the lower support portion 210. That is, the upper support part 250 has a disc shape as a whole, and a coupling part 252 is formed on the upper support part 250 so as to be inserted and fixed in the charging part 240 between the inner core part 220 and the outer wall part 230 . The upper support portion 210 may be made of a high strength material to withstand the cold water pressure, and may be made of substantially the same material as the inner core portion 220. The lower supporting part 210 is inserted between the inner core part 220 and the outer wall part 230 and then the ITO granule powder is filled in the charging part 240 and then the upper supporting part 250 is inserted into the inner core part 220 and the outer wall part 230 230, respectively.

As described above, the mold 200 according to an embodiment of the present invention can be used for manufacturing a hollow cylindrical ITO target molded body, and the method of filling the charging part 240 of the mold 200 with the ITO granular powder will be described later .

5 is a schematic cross-sectional view of a cold isostatic apparatus for manufacturing an ITO target shaped body according to an embodiment of the present invention.

Referring to FIG. 5, the cold isostatic press 300 for manufacturing an ITO target shaped body according to an embodiment of the present invention includes an outer wall 301, a top cover 302, a cold water supply unit 303 And a rack 310 for positioning the mold 200.

The rack 310 includes a pedestal 311 capable of supporting the mold 200 and connecting portions 313 and 314 capable of connecting the pedestal 311 to the fixing portion 312.

A plurality of molds 200 filled with the ITO granular powder 241 may be placed on the pedestal 311 of the rack 310.

The fixed portion 312 (e.g., a metal chain) connected to the top cover 302 of the cold isostatic apparatus 300 may fix the rack 310 in the cold isostatic apparatus 300.

The operation of the cold isostatic apparatus 300 will be briefly described below.

First, one or more molds 200 according to an embodiment of the present invention are placed on the rack 310 and placed in the cold isostatic apparatus 300. At this time, the top cover 302 and the rack 310 can be fixed by the fixing portion 312 and can be moved integrally into the CCF 300. In addition, the rack 310 may be positioned above a lower surface of the cold isostatic apparatus 300 at a predetermined height so that the cold hydrostatic pressure can uniformly act on the upper and lower ends of the mold 200.

Then, the top cover 302 is sealed, and cold water is supplied through the cold water supply unit 303. When the cold water pressure reaches a certain pressure, the supply of the cold water is stopped and the valve 304 is closed. The cold isostatic pressure is applied to the outer wall 230 of the mold 200 for a certain period of time to form the ITO granule powder filled in the mold 200 to be a cylindrical ITO target molded article having a constant density.

Hereinafter, a method of manufacturing an ITO target molded article according to an embodiment of the present invention will be described with reference to FIG. 3, using the mold 200 and the cold isostatic apparatus 300 described above.

3 is a flowchart of a method of manufacturing an ITO target molded article according to an embodiment of the present invention.

Referring to FIG. 3, a method of manufacturing an ITO target molded body according to an embodiment of the present invention includes the steps of forming an ITO granule powder (S300), filling the ITO target powder molding mold (S310) And pressing the ITO granule powder filled in the mold (S320).

First, an ITO granulated powder is formed (S300).

The granular powder in this step can be prepared by preparing an ITO slurry containing a certain concentration of ITO fine powder and organic binder and drying the slurry under a predetermined condition. This is substantially the same as that described above, so the description is omitted here.

In one embodiment of the present invention, an ITO granule powder having a single average particle diameter can be formed. The average particle diameter of the ITO granulated powder can be set to a certain size within a range of about 2 탆 to 100 탆.

When the ITO granulated powder thus formed is used, the flowability of the powder is excellent as compared with the case where the ITO fine powder having an average particle size of nm scale is used as it is. Accordingly, the powder can be uniformly filled in the filled portion of the mold, and thus an ITO formed body having a more uniform molding density can be manufactured.

In the present invention, the ITO granulated powder is prepared so as to have flowability of about 50 g / sec to 80 g / sec. If the flowability of the ITO granulated powder is less than about 50 g / sec, the powder may not be uniformly filled in the entirety of the filled part of the mold for manufacturing the ITO formed body, resulting in nonuniform molding density of the final ITO formed body. In addition, when the flowability exceeds about 80 g / sec, there is no great difference in the degree to which the powder is evenly filled in the whole charged portion of the mold.

In another embodiment of the present invention, an ITO granule powder group having an average particle size of different sizes can be formed.

When the ITO granular powder group having different average particle sizes thus formed is used, the filling rate of the powder filled in the filling part of the mold is improved as compared with the case where only ITO powder having a single average particle diameter is used. That is, since the granular powder having a smaller particle diameter can be located in the gap between the granular powders having larger particle diameters, the filling rate is improved.

When the filling rate is improved, the molding density of the ITO target molded article obtained after cold isostatic pressing becomes high.

In another embodiment of the present invention, the ITO granulated powder group comprises a first granular powder having an average particle size of about 50-70 microns, a second granular powder having an average particle size of about 15-30 microns and an average of about 5-10 microns And a third granular powder having a particle diameter. In this way, the charging rate described above can be improved.

Next, the obtained ITO granular powder or ITO granulated powder group is charged (S310) to the charging part 240 of the mold 200. [

In one embodiment of the present invention, the ITO granule powder may be injected into the filling part 240 before the upper support part 250 is coupled to the mold 200. At this time, a powder injector (not shown) may be separately installed on the upper part of the mold 200 so that the ITO powder can be charged at a constant speed. The upper support 250 may then be coupled to the mold 200 to seal the mold 200.

Subsequently, the ITO granular powder filled in the mold is subjected to pressure treatment (S320).

The pressurizing treatment can be performed by using, for example, water pressure, hydraulic pressure or air pressure. However, the present invention is not limited thereto

In an embodiment of the present invention, a cold hydrostatic pressure treatment method using water pressure may be used. That is, the mold 200 filled with the ITO powder, the rack 310 and the upper cover 302, which are mounted on the mold 200, are all positioned in the cold isostatic apparatus 300, (Not shown). And supplies the cold water through the cold water supplying unit 303.

As the cold water is supplied, the pressure in the cold water booster 300 gradually rises. At this time, the cold constant can be supplied until the cold static pressure applied to the outer wall 230 of the mold 200 reaches, for example, about 294 MPa.

After the cold isostatic pressure is reached, the valve 304 of the cold isostatic apparatus 300 is closed, and the ITO granulated powder charged in the mold 200 is cooled to a predetermined time, for example, about 1 To 2 hours.

After the cold isostatic pressing is completed, the mold 200 is taken out of the cold isostatic apparatus 300, and the mold 200 is disassembled to separate the ITO target molded body from the mold 300 (S330).

Such an ITO target molded body is formed by using an ITO granulated powder having excellent flowability, so that the molding density over the entire ITO target molded body is uniform. In addition, when the filled portion of the mold is filled with the ITO granular powder group containing the ITO granulated powders having different average particle diameters, the filling rate can be increased and the molding density of the ITO target molded body can be increased.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

The above-described ITO granular powder and the cylindrical ITO target molded article containing the same have the following effects.

First, the ITO powder can be more uniformly filled in the filling portion of the mold by preparing the ITO fine powder in a granular form. Therefore, the molding density of the ITO target molded body can be made more uniform.

Second, ITO granular powder having different average particle diameters may be mixed and filled in a filled portion of the mold to improve the filling rate. Therefore, the molding density of the ITO target molded article can be improved.

Claims (4)

An ITO granular powder comprising a first granular powder having an average particle size of from 50 to 70 mu m, a second granular powder having an average particle size of from 15 to 30 mu m and a third granular powder having an average particle size of from 5 to 10 mu m. The method according to claim 1, Wherein the first granular powder is 10 - 25 wt%, the second granular powder is 25 - 40 wt%, and the third granular powder is 40 - 55 wt%. The method according to claim 1, ITO granule powder having a flowability of 50 to 80 g / sec. A cylindrical ITO target molded article comprising the ITO granule powder according to any one of claims 1 to 3.

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