CN112898014B - Atmosphere sintering method of ITO (indium tin oxide) particles - Google Patents

Abstract

The invention discloses an atmosphere sintering method of ITO particles, belonging to the technical field of ITO target processingThe following steps: s1, preparing an ITO biscuit: in is mixed with₂O₃Powder and SnO₂Uniformly mixing the powder to obtain raw material powder, adding an adhesive into the raw material powder, uniformly mixing, spraying and granulating, filling the mixture into a mold, and performing mold pressing treatment and cold isostatic pressing treatment to obtain an ITO biscuit; s2, preparing an ITO target: degreasing and vacuumizing the ITO biscuit, and then filling oxygen into pores of the ITO biscuit so as to sinter the ITO biscuit for 5-12 hours under the conditions of normal pressure, pure oxygen atmosphere and 1500-. The invention solves the problem of low density of the ITO target material manufactured by the traditional ITO target material atmosphere sintering process.

Description

Atmosphere sintering method of ITO (indium tin oxide) particles

Technical Field

The invention relates to the technical field of ITO target processing, in particular to an atmosphere sintering method of ITO particles.

Background

The ITO target material is an important raw material for preparing ITO conductive glass. The ITO target can be applied to a variety of electronic products, such as touch panels, organic light emitting flat panel displays, plasma displays, automotive anti-heat defogging glasses, solar cells, photoelectric converters, transparent heater anti-static films, infrared reflection devices, etc., in addition to Liquid Crystal Display (LCD) panels. The ITO target material can form a transparent ITO conductive film on glass after sputtering, and the performance of the transparent ITO conductive film is a key factor for determining the quality, the production efficiency and the yield of conductive glass products. The manufacturers of conductive glass require that conductive glass with uniform resistance and transmittance and no fluctuation can be stably and continuously produced in the production process, so that the ITO target material should keep the performance unchanged in the whole film coating process.

The ITO biscuit after the forming process is only a semi-finished product, and the biscuit needs to be further sintered to obtain the ITO target. The sintering method of the ITO biscuit mainly comprises a hot isostatic pressing method, a hot pressing method and a normal pressure sintering method. The normal pressure sintering method is also called atmosphere sintering method, and refers to a method of manufacturing a high-density target blank in a prepressing manner and sintering the target blank in a certain atmosphere and temperature. The atmosphere and temperature are strictly controlled respectively in the normal pressure sintering method, so that the growth of crystal grains is avoided, and the uniformity of crystal grain distribution is improved. The method has the advantages of low production cost, high target material density, capability of preparing large-size target materials and the like.

Because the atmosphere sintering method is operated under normal pressure, the densification speed of the ITO biscuit in the sintering process is low, and the densification process of the ITO target can be completed only by needing higher sintering temperature and longer heat preservation time, so that the target has larger grains and the strength is reduced.

In view of the above, the present invention provides a novel method for atmosphere sintering ITO particles.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an atmosphere sintering method of ITO particles, which solves the problem that the ITO target material manufactured by the traditional ITO target material atmosphere sintering process is low in density.

In order to achieve the purpose, the invention provides the following technical scheme:

an atmosphere sintering method of ITO particles comprises the following steps:

s1 preparation of ITO biscuit

In is mixed with₂O₃Powder and SnO₂Uniformly mixing the powder to obtain raw material powder, adding an adhesive into the raw material powder, uniformly mixing, spraying and granulating, filling the mixture into a mold, and performing mold pressing treatment and cold isostatic pressing treatment to obtain an ITO biscuit;

s2 preparation of ITO target material

Degreasing and vacuumizing the ITO biscuit, and then filling oxygen into pores of the ITO biscuit so as to sinter the ITO biscuit for 5-12 hours under the conditions of normal pressure, pure oxygen atmosphere and 1500-.

More preferably: in step S1, a biscuit is obtained by molding with a die pressing and cold isostatic pressing composite method, and the molding pressure is 50-230 MPa.

More preferably: in step S2, during the vacuuming and the oxygen charging, the degree of vacuum is 10^-4-10^-2Pa, oxygenation pressure of 10-100KPa, and pressure maintaining time of 10-60 min.

More preferably: in step S2, the ITO biscuit is sintered in a sintering furnace, in which a supporting device for placing the ITO biscuit is disposed.

More preferably: the supporting device comprises a fixed plate fixed in the sintering furnace, the top surface of the fixed plate is provided with a placing surface for placing the ITO biscuit, the placing surface is obliquely arranged, the placing surface is provided with a plurality of grooves for oxygen filling, and the plurality of grooves are arranged at equal intervals along the oblique direction of the placing surface;

the lower end of the placing surface is fixedly provided with a positioning block used for limiting the ITO biscuit to slide downwards, the positioning block is in contact with the ITO biscuit, and the fixing plate is provided with a pushing mechanism used for pushing the ITO biscuit to slide upwards along the oblique direction of the placing surface so as to enable the fixing plate to be separated from the positioning block.

More preferably: the pushing mechanism comprises a pushing block, a cavity, a sliding plate, a motor, a gear, a rotating shaft and a cavity;

the cavity and the cavity are both positioned in the fixed plate, the cavity is positioned below the cavity and communicated with the cavity, one end of the rotating shaft is rotatably connected with the side wall of the cavity, the other end of the rotating shaft is connected with the output shaft of the motor, the top of the cavity is provided with a slotted hole, and the length direction of the slotted hole is the same as the inclination direction of the placing surface;

the push block is located on one side of the lower end of the ITO biscuit, the push block is inserted into the groove hole and fixed with the sliding plate, the sliding plate is located in the cavity, a tooth surface is arranged on the bottom surface of the sliding plate, the gear is located below the sliding plate and meshed with the tooth surface, and the gear is located in the cavity and fixed on the rotating shaft.

More preferably: the push block and the positioning block are respectively positioned on the same side of the ITO biscuit, and the distance between the slotted hole and the lower end edge of the placing surface is smaller than the distance between the positioning block and the lower end edge of the placing surface.

More preferably: limiting columns are fixed on the placing surface and located on two opposite sides of the ITO biscuit.

More preferably: a plurality of ITO biscuit is placed on the placing surface, and adjacent ITO biscuit is separated through the limiting column.

More preferably: the motor is arranged on the outer surface of the sintering furnace.

In conclusion, the invention has the following beneficial effects: according to the invention, oxygen is filled into the pores of the degreased ITO biscuit, so that in the normal-pressure oxygen atmosphere sintering process, the oxygen in the pores of the ITO biscuit and the oxygen in the hearth jointly inhibit the decomposition and volatilization of ITO in the sintering process, thereby preparing the large-size high-density ITO target material in a short sintering time, and solving the problem of low density of the ITO target material prepared by the traditional ITO target material atmosphere sintering process. Because the traditional sintering process is used for sintering the ITO target in the sintering furnace, the ITO biscuit is usually directly placed on the burning bearing plate in the hearth for sintering, and because the bottom surface of the ITO biscuit is in contact with the burning bearing plate, the contact part of the ITO biscuit and the burning bearing plate cannot be oxygenated, so that the ITO biscuit is not fully sintered and the forming effect is poor. In order to overcome the defects, the invention designs a novel supporting device so as to improve the sintering yield of the ITO target.

Drawings

FIG. 1 is a block flow diagram of an embodiment, primarily for embodying an atmosphere sintering method for ITO particles;

FIG. 2 is a schematic structural diagram of an embodiment, which is mainly used for embodying a placement structure of an ITO biscuit;

FIG. 3 is a schematic structural diagram of an embodiment, which is mainly used for embodying a placement structure of an ITO biscuit;

FIG. 4 is a schematic structural diagram of an embodiment, which is mainly used for embodying the structure of the supporting device;

fig. 5 is a schematic sectional view of the embodiment, mainly used for embodying the structure of the pushing mechanism.

In the figure, 1, fixing plate; 2. an ITO biscuit; 3. placing the noodles; 4. a groove; 5. a limiting post; 6. positioning blocks; 7. a pushing mechanism; 71. a push block; 72. a slot; 73. a cavity; 74. a slide plate; 75. a gear; 76. a rotating shaft; 77. a chamber; 78. tooth surface.

Detailed Description

The invention is described in detail below with reference to the figures and examples.

Example 1: an atmosphere sintering method of ITO particles, as shown in FIG. 1, comprises the following steps:

s1 preparation of ITOgreen body 2

In is mixed with₂O₃Powder and SnO₂The powder is prepared from the following components in percentage by mass 9: 1, uniformly mixing to obtain raw material powder, adding a binding agent such as PVA (polyvinyl alcohol) and the like into the raw material powder, uniformly mixing, spraying and granulating, then filling the mixture into a mould, and performing mould pressing treatment and cold isostatic pressing treatment to obtain the product with the density of 4-4.89g/cm³ITOgreen compact 2.

Preferably, the biscuit is obtained by adopting a die pressing and cold isostatic pressing composite method, and the forming pressure is 100 MPa.

S2 preparation of ITO target material

Degreasing and vacuumizing theITO biscuit 2, and then filling oxygen into pores of theITO biscuit 2 to sinter theITO biscuit 2 for 8 hours under the conditions of normal pressure, pure oxygen atmosphere and 1550 ℃ to obtain the ITO target.

Preferably, the degreasing treatment is carried out at a temperature of 600 ℃ for a time of 40 hours.

Preferably, the vacuum degree during the vacuum treatment and the oxygenation is 10^-3Pa, oxygenation pressure of 50KPa, and pressure maintaining time of 30 min.

In the technical scheme, oxygen is filled into the pores of the degreasedITO biscuit 2, so that in the normal-pressure oxygen atmosphere sintering process, the oxygen in the pores of theITO biscuit 2 and the oxygen in the hearth jointly inhibit the decomposition and volatilization of ITO in the sintering process, and the large-size high-density ITO target can be prepared in a short sintering time.

Referring to FIGS. 2-5, in step S2, the sintering process ofITO greenbody 2 is performed in a sintering furnace having a support device disposed therein for holdingITO greenbody 2. Because the conventional sintering process is to sinter the ITO target in a sintering furnace, theITO biscuit 2 is usually directly placed on a burning bearing plate in a hearth for sintering, and because the bottom surface of theITO biscuit 2 is in contact with the burning bearing plate, the contact part of theITO biscuit 2 and the burning bearing plate cannot be oxygenated, so that theITO biscuit 2 is insufficiently sintered and has poor molding effect. In order to overcome the defects, the invention designs a novel supporting device so as to improve the sintering yield of the ITO target.

Referring to fig. 2-5, in particular, the supporting device comprises a fixedplate 1 fixed in a sintering furnace, and a placingsurface 3 for placing anITO biscuit 2 is arranged on the top surface of the fixedplate 1. The placingsurface 3 is obliquely arranged, a plurality ofgrooves 4 used for oxygen filling are formed in the placingsurface 3, thegrooves 4 are arranged in a plurality of intervals in the oblique direction of the placingsurface 3, and thegrooves 4 are arranged in parallel. Apositioning block 6 for limiting the downward sliding of theITO biscuit 2 along the inclined direction of the placingsurface 3 is fixed at the lower end of the placingsurface 3, and thepositioning block 6 is in contact with theITO biscuit 2. A limitingcolumn 5 is fixed on the placingsurface 3, the limitingcolumn 5 is located on two opposite sides of theITO biscuit 2, and the limitingcolumn 5 is in contact with the side portion of theITO biscuit 2. A plurality ofITO bisques 2 have been placed on placing theface 3, and a plurality ofITO bisques 2 are arranged along 4 length direction of recess equidistant, andadjacent ITO bisques 2 separate throughspacing post 5.

Referring to fig. 2-5, a pushingmechanism 7 is disposed on the fixingplate 1, and the pushingmechanism 7 is configured to push theITO biscuit 2 to slide upwards along the inclined direction of the placingsurface 3, so that the fixingplate 1 is separated from thepositioning block 6, and the bottom surface of theITO biscuit 2 can be in full contact with oxygen in thegroove 4. The pushingmechanism 7 includes a pushingblock 71, acavity 73, a slidingplate 74, a motor, agear 75, a rotatingshaft 76 and achamber 77.Cavity 73 andcavity 77 all are located fixedplate 1, andcavity 77 is locatedcavity 73 below and communicates withcavity 73, andcavity 73 inner bottom surface sets up for the slope and inclination, the direction all with place theface 3 inclination, the direction the same. One end of therotating shaft 76 is rotatably connected with the side wall of thechamber 77, and the other end of the rotating shaft is connected with an output shaft of the motor. EachITO biscuit 2 corresponds to threepositioning blocks 6 and two pushingblocks 71, the threepositioning blocks 6 are arranged on the same side of theITO biscuit 2 at equal intervals, and the two pushingblocks 71 are arranged between the adjacent positioning blocks 6.

Referring to FIGS. 2 to 5, aslot 72 is formed at the top of thecavity 73, the length direction of theslot 72 is the same as the inclination direction of the placingsurface 3, and thepush block 71 is located on one side of the lower end of the ITOgreen compact 2. In order to position theITO biscuit 2 by thepositioning block 6, specifically, thepush block 71 and thepositioning block 6 are located on the same side of theITO biscuit 2, and the distance between theslot 72 and the lower end edge of the placingsurface 3 is smaller than the distance between thepositioning block 6 and the lower end edge of the placingsurface 3. The lower end of thepush block 71 is inserted into theslot 72 and fixed with theslide plate 74, and theslot 72 is matched with thepush block 71, so that thepush block 71 can move smoothly in theslot 72 along the length direction of theslot 72. Aslide plate 74 is positioned in thecavity 73 and contacts the bottom of thecavity 73, atooth surface 78 is provided on the bottom surface of theslide plate 74, agear 75 is positioned below theslide plate 74 and is meshed with thetooth surface 78, and thegear 75 is positioned in thechamber 77 and is fixed on therotating shaft 76.

The using process and the principle of the supporting device are as follows: when theITO biscuit 2 is sintered, the plurality ofITO biscuits 2 are firstly placed on the placingsurface 3 on the fixingplate 1, so that theITO biscuits 2 are in contact with thepositioning block 6, and two opposite sides of the plurality ofITO biscuits 2 are in contact with the limitingcolumns 5 respectively. Although thegrooves 4 are filled with oxygen, the parts of the placingsurface 3 other than thegrooves 4 and the contact parts of the positioning blocks 6 and theITO biscuit 2 are not permeable to oxygen, so the invention is provided with a pushingmechanism 7 to ensure that theITO biscuit 2 can move upwards along the oblique direction of the placingsurface 3. In the process that theITO biscuit 2 moves upwards along the inclined direction of the placingsurface 3, oxygen in thegroove 4 can be in overall contact with the bottom surface of theITO biscuit 2, and theITO biscuit 2 is separated from thepositioning block 6, so that the contact part of theITO biscuit 2 and thepositioning block 6 can also be permeated by oxygen, the contact area of theITO biscuit 2 and the oxygen is enlarged, and the sintering yield is improved.

The using process and principle of the pushingmechanism 7 are as follows: when theITO biscuit 2 needs to move upwards along the inclined direction of the placingsurface 3, the motor is started to enable therotating shaft 76 to drive thegear 75 to rotate, thegear 75 is meshed with thegear 75 on the slidingplate 74, therefore, when thegear 75 rotates, sliding moves upwards along the inclined direction of the inner bottom surface of thecavity 73, at the moment, the pushingblock 71 moves towards the direction close to theITO biscuit 2 in the slottedhole 72, and after the pushingblock 71 is contacted with theITO biscuit 2, the pushingblock 71 drives theITO biscuit 2 to move upwards along the inclined direction of the placingsurface 3.

Example 2: an atmosphere sintering method of ITO particles, which is different fromembodiment 1, comprises the steps of:

s1 preparation of ITO biscuit

In is mixed with₂O₃Powder and SnO₂The powder is prepared from the following components in percentage by mass 9: 1, uniformly mixing to obtain raw material powder, adding a binding agent such as PVA (polyvinyl alcohol) and the like into the raw material powder, uniformly mixing, spraying and granulating, then filling the mixture into a mould, and performing mould pressing treatment and cold isostatic pressing treatment to obtain the product with the density of 4-4.89g/cm³The ITO green compact of (1).

Preferably, the biscuit is obtained by adopting a die pressing and cold isostatic pressing composite method, and the forming pressure is 50 MPa.

S2 preparation of ITO target material

Degreasing and vacuumizing the ITO biscuit, and then filling oxygen into pores of the ITO biscuit so as to sinter the ITO biscuit for 5 hours under the conditions of normal pressure, pure oxygen atmosphere and 1500 ℃ to obtain the ITO target.

Preferably, the degreasing treatment is carried out at a temperature of 500 ℃ for a time of 30 hours.

Preferably, the vacuum degree during the vacuum treatment and the oxygenation is 10^-4Pa, oxygenation pressure of 10KPa and pressure maintaining time of 10 min.

Example 3: an atmosphere sintering method of ITO particles, which is different fromembodiment 1, comprises the steps of:

s1 preparation of ITO biscuit

In is mixed with₂O₃Powder and SnO₂The powder is prepared from the following components in percentage by mass 9: 1, uniformly mixing to obtain raw material powder, adding a binding agent such as PVA (polyvinyl alcohol) and the like into the raw material powder, uniformly mixing, spraying and granulating, then filling the mixture into a mould, and performing mould pressing treatment and cold isostatic pressing treatment to obtain the product with the density of 4-4.89g/cm³The ITO green compact of (1).

Preferably, the biscuit is obtained by adopting a die pressing and cold isostatic pressing composite method, and the forming pressure is 230 MPa.

S2 preparation of ITO target material

Degreasing and vacuumizing the ITO biscuit, and then filling oxygen into pores of the ITO biscuit so as to sinter the ITO biscuit for 12 hours under the conditions of normal pressure, pure oxygen atmosphere and 1620 ℃ to obtain the ITO target.

Preferably, the degreasing treatment is carried out at a temperature of 800 ℃ for a time of 50 hours.

Preferably, the vacuum degree during the vacuum treatment and the oxygenation is 10^-2Pa, oxygenation pressure of 100KPa and pressure maintaining time of 60 min.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that several improvements and modifications without departing from the principle of the present invention will occur to those skilled in the art, and such improvements and modifications should also be construed as within the scope of the present invention.

Claims (8)

1. An atmosphere sintering method of ITO particles is characterized in that: the method comprises the following steps:

s1 preparation of ITO green body (2)

In is mixed with₂O₃Powder and SnO₂Uniformly mixing the powder to obtain raw material powder, adding an adhesive into the raw material powder, uniformly mixing, spraying and granulating, filling the mixture into a die, and performing die pressing treatment and cold isostatic pressing treatment to obtain an ITO biscuit (2);

s2 preparation of ITO target material

Degreasing and vacuumizing the ITO biscuit (2), and then filling oxygen into pores of the ITO biscuit (2) to sinter the ITO biscuit (2) for 5-12 hours under the conditions of normal pressure, pure oxygen atmosphere and 1500-;

in step S2, sintering the ITO biscuit (2) in a sintering furnace, wherein a supporting device for placing the ITO biscuit (2) is arranged in the sintering furnace;

the supporting device comprises a fixing plate (1) fixed in the sintering furnace, a placing surface (3) used for placing the ITO biscuit (2) is arranged on the top surface of the fixing plate (1), the placing surface (3) is arranged in an inclined mode, a plurality of grooves (4) used for filling oxygen are formed in the placing surface (3), and the plurality of grooves (4) are arranged at equal intervals along the inclined direction of the placing surface (3);

a positioning block (6) used for limiting the ITO biscuit (2) to slide downwards is fixed at the lower end of the placing surface (3), the positioning block (6) is in contact with the ITO biscuit (2), a pushing mechanism (7) is arranged on the fixing plate (1), and the pushing mechanism (7) is used for pushing the ITO biscuit (2) to slide upwards along the inclining direction of the placing surface (3) so that the fixing plate (1) is separated from the positioning block (6).

2. An atmosphere sintering method of ITO particles according to claim 1, wherein: in step S1, a biscuit is obtained by molding with a die pressing and cold isostatic pressing composite method, and the molding pressure is 50-230 MPa.

3. An atmosphere sintering method of ITO particles according to claim 1, wherein: in step S2, during the vacuuming and the oxygen charging, the degree of vacuum is 10^-4-10^-2Pa, oxygenation pressure of 10-100KPa, and pressure maintaining time of 10-60 min.

4. An atmosphere sintering method of ITO particles according to claim 1, wherein: the pushing mechanism (7) comprises a pushing block (71), a cavity (73), a sliding plate (74), a motor, a gear (75), a rotating shaft (76) and a cavity (77);

the cavity (73) and the cavity (77) are both positioned in the fixed plate (1), the cavity (77) is positioned below the cavity (73) and communicated with the cavity (73), one end of the rotating shaft (76) is rotatably connected with the side wall of the cavity (77), the other end of the rotating shaft is connected with the motor output shaft, a slotted hole (72) is formed in the top of the cavity (73), and the length direction of the slotted hole (72) is the same as the inclined direction of the placing surface (3);

the push block (71) is located on one side of the lower end of the ITO biscuit (2), the push block (71) is inserted into the slotted hole (72) and fixed with the sliding plate (74), the sliding plate (74) is located in the cavity (73), a tooth surface (78) is arranged on the bottom surface of the sliding plate (74), the gear (75) is located below the sliding plate (74) and meshed with the tooth surface (78), and the gear (75) is located in the cavity (77) and fixed on the rotating shaft (76).

5. An atmosphere sintering method of ITO particles according to claim 4, wherein: the push block (71) and the positioning block (6) are respectively positioned on the same side of the ITO biscuit (2), and the distance between the slotted hole (72) and the lower end edge of the placing surface (3) is smaller than the distance between the positioning block (6) and the lower end edge of the placing surface (3).

6. An atmosphere sintering method of ITO particles according to claim 1, wherein: limiting columns (5) are fixed on the placing surface (3), and the limiting columns (5) are located on two opposite sides of the ITO biscuit (2).

7. An atmosphere sintering method of ITO particles according to claim 6, wherein: a plurality of ITO (indium tin oxide) biscuits (2) are placed on the placing surface (3), and the adjacent ITO biscuits (2) are separated by the limiting columns (5).

8. An atmosphere sintering method of ITO particles according to claim 4, wherein: the motor is arranged on the outer surface of the sintering furnace.

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