A method of sintering a long metal oxide tubular target

Abstract

The application relates to a sintering method of a long metal oxide tubular target, which comprises the following steps: placing a supporting plate with a central hole and a ring-shaped air hole in a sintering furnace, placing a ring-shaped fence on the supporting plate, laying a layer of small balls on the supporting plate between the central hole and the air hole, vertically placing a tubular target blank on the small balls, sleeving a sleeve on the outside of the tubular target blank and vertically placing the sleeve on the ring-shaped fence, forming a ring-shaped cavity communicated with the ring-shaped air hole between the sleeve and the tubular target blank, filling large balls in the ring-shaped cavity, and then sintering the tubular target. The bottom and the outer circle of the tubular target blank are supported by spherical refractory materials, and the interspaces between the balls are used for the diffusion of the sintering atmosphere, so that the sintering of the tubular target with a length of more than or equal to 1200 mm is realized. The sintering deformation of the tubular target is less than or equal to 0.5 mm, the deformation is small, the sintering quality is good, and the long metal oxide tubular target is suitable for batch production.

Description

Technical Field

[0001] This invention relates to a target sintering method, and more particularly to a sintering method for a long metal oxide tubular target. Background Technology

[0002] Metal oxide targets are mainly used in magnetron sputtering coating machines to manufacture thin films of corresponding materials. Target types are divided into planar targets (flat plates) and rotating targets (tubular shapes). Rotating targets with high utilization rates are increasingly favored by users.

[0003] Existing tubular metal oxide targets are mostly composed of several sections spliced ​​together. The presence of seams affects the coating quality. Increasing the length of individual tubular target sections and reducing seams is an industry trend. However, ultra-long tubular targets, such as tubular target blanks with a length ≥1200mm, are prone to significant bending deformation during sintering, making it impossible to produce targets of suitable dimensions. Therefore, there is a need to develop a sintering method suitable for ultra-long tubular target blanks with a length ≥1200mm. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a sintering method for a long metal oxide tubular target. The method uses a sphere to support the outer wall of the tubular target blank. When the tubular target shrinks during the sintering process, the sphere can always contact the outer wall of the tubular target to provide support for the target. The tubular target obtained by this method has small deformation and good sintering quality.

[0005] The technical solution to the above-mentioned technical problems is: a sintering method for long metal oxide tubular targets, comprising the following steps:

[0006] (1) A sintering plate is placed in the sintering furnace. The sintering plate has a central air hole in the middle and an annular air vent is arranged on the sintering plate outside the central air hole. The annular air vent is composed of multiple small holes.

[0007] (2) Place an annular enclosure on the firing plate with the central vent hole as the center point, and place the annular vent hole inside the annular enclosure;

[0008] (3) Place a layer of small balls with a diameter of 0.5 to 3 mm on the firing plate between the central pore and the vent hole;

[0009] (4) Place the tubular target blank upright on the small ball;

[0010] (5) The sleeve is placed on the outside of the tubular target blank and erected on the annular enclosure. An annular cavity is formed between the sleeve and the tubular target blank. The annular cavity is located above the annular vent hole and communicates with the annular vent hole.

[0011] (6) In the cavity formed between the sleeve and the tubular target blank, a large ball with a diameter 1.5 to 2 mm larger than the small ball is filled in. The diameter of the large ball is larger than the diameter of the small hole that makes up the vent hole.

[0012] (7) Then the tubular target is sintered in a sintering furnace.

[0013] Furthermore, in step (6), the height of the target material is 50% ≤ the height of the large ball ≤ 80% of the height of the target material, and the height of the tubular target material blank above the large ball is less than or equal to 1200 mm.

[0014] Furthermore, the small and large spheres are alumina spheres or zirconium oxide spheres with a purity of not less than 99%.

[0015] Furthermore, the length of the tubular target blank is 1200mm to 6000mm.

[0016] Furthermore, the inner diameter of the annular enclosure is 5 to 25 mm larger than the outer diameter of the tubular target blank.

[0017] Furthermore, the diameter of the large sphere is 2 to 5 mm.

[0018] In this invention, a layer of small balls with a diameter of 0.5-3 mm is laid on a firing plate, a tubular target blank is placed on the small balls, and a sleeve is then placed over the tubular target blank. Then, large balls with a diameter of 1.5-2 mm larger than the small balls are used to fill the space between the tubular target blank and the sleeve. That is, large balls with a diameter of 2-5 mm are used to support the outer wall of the tubular target blank. During the sintering process, when the tubular target shrinks inward, the cavity between it and the sleeve will increase, while the large balls move downward under their own weight, so that they can always be in contact with the outer wall of the tubular target to provide support for the target. This invention uses spherical refractory material to support the bottom and outer circumference of the tubular target blank, and utilizes the gaps formed between the spheres to diffuse the sintering atmosphere. It can be used for sintering tubular target blanks with a length ≥1200mm. Due to the large pores between the spheres, the sintering atmosphere diffuses easily, and the outer circumference of the tubular target is supported, making it less prone to large bending. The sintered tubular target has a bending deformation ≤0.5mm, with small deformation and good sintering quality, making it suitable for mass production of long-sized metal oxide tubular targets.

[0019] The technical features of a sintering method for a long metal oxide tubular target according to the present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 : Schematic diagram of the support state during the sintering of the tubular target material of the present invention.

[0021] Figure 2 : Schematic diagram of the bottom support during the sintering of the tubular target material of the present invention.

[0022] Figure 3 : Figure 2 AA sectional view.

[0023] Figure 4 The bottom view of the firing plate used in this invention.

[0024] In the figure: 1-Sintering plate, 11-Annular vent hole, 12-Central vent, 13-Air outlet, 2-Annular enclosure, 3-Sleeve, 4-Small ball, 5-Large ball, 6-Tube-shaped target blank. Detailed Implementation

[0025] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] Example 1

[0027] ITO tubular target blanks with a length of 1200 mm, a wall thickness of 14 mm, and an inner diameter of 160 mm were formed using cold isostatic pressing. A firing plate with a central vent hole was placed in a sintering furnace. An annular vent hole, composed of multiple small holes, was formed around the central vent hole. An annular baffle was placed on the firing plate, centered on the central vent hole, with the annular vent hole located within the baffle. The inner diameter of the baffle was 25 mm larger than the outer diameter of the tubular target blank. A layer of 3 mm diameter alumina spheres was laid on the firing plate between the central vent hole and the vent holes. The 1200 mm long tubular target blank was then placed upright on the 3 mm diameter alumina spheres.

[0028] A refractory sleeve capable of withstanding sintering temperatures is fitted over the tubular target blank and erected on an annular enclosure. An annular cavity is formed between the sleeve and the target, located above and communicating with the annular vent holes. Large alumina spheres with a diameter of 5 mm and a height of 960 mm are filled into this annular cavity. The diameter of the alumina spheres is larger than the diameter of the small holes forming the vent holes.

[0029] The target was then sintered in a sintering furnace at a temperature of 1600℃ for 8 hours. The resulting tubular target exhibited a bending deformation of 0.5 mm along its length and a density of 7.13 g / cm³. 3 .

[0030] Example 2

[0031] ITO tubular blanks with a length of 1200 mm, a wall thickness of 14 mm, and an inner diameter of 160 mm were formed using cold isostatic pressing. A firing plate with a central vent hole was placed in a sintering furnace. An annular vent hole, composed of multiple small holes, was formed around the central vent hole. An annular baffle was placed on the firing plate, centered on the central vent hole, with the annular vent hole located within it. The inner diameter of the annular baffle was 5 mm larger than the outer diameter of the tubular target blank. A layer of 0.5 mm diameter alumina spheres was laid on the firing plate between the central vent hole and the vent holes. The 1200 mm long tubular target blank was then placed upright on the 0.5 mm diameter alumina spheres.

[0032] A refractory sleeve capable of withstanding sintering temperatures is fitted over the tubular target blank and erected on an annular enclosure. An annular cavity is formed between the sleeve and the target, located above and communicating with the annular vent holes. Large alumina spheres with a diameter of 2 mm and a height of 900 mm are filled into this annular cavity. The diameter of the alumina spheres is larger than the diameter of the small holes forming the vent holes.

[0033] The target was then sintered in a sintering furnace at a temperature of 1500℃ for 10 hours. The resulting tubular target exhibited a bending deformation of 0.4 mm along its length and a density of 7.09 g / cm³. 3 .

[0034] Example 3

[0035] A tubular ITO blank with a length of 3000 mm, a wall thickness of 15 mm, and an inner diameter of 170 mm was formed using cold isostatic pressing. A firing plate with a central vent hole was placed in a sintering furnace. An annular vent hole, composed of multiple small holes, was formed around the central vent hole. An annular baffle was placed on the firing plate, centered on the central vent hole, with the annular vent hole located within the baffle. The inner diameter of the baffle was 15 mm larger than the outer diameter of the tubular target blank. A layer of 1 mm diameter alumina spheres was laid on the firing plate between the central vent hole and the vent holes. The 1500 mm long tubular target blank was then placed upright on the 1 mm diameter alumina spheres.

[0036] A refractory sleeve capable of withstanding sintering temperatures is fitted over the tubular target blank and erected on an annular enclosure. An annular cavity is formed between the sleeve and the target, located above and communicating with the annular vent holes. Large alumina spheres with a diameter of 3 mm and a height of 2000 mm are filled into this annular cavity. The diameter of the alumina spheres is larger than the diameter of the small holes forming the vent holes.

[0037] The target was then sintered in a sintering furnace at a temperature of 1550℃ for 12 hours. The resulting tubular target exhibited a bending deformation of 0.5 mm along its length and a density of 7.12 g / cm³. 3 .

[0038] Comparative Example 1:

[0039] The basic operation is the same as in Example 1, except that: the height of the alumina sphere is 1000 mm, the sintered tubular target has a bending deformation of 0.5 mm in the length direction, and the target density is 7.01 g / cm³. 3 .

[0040] In Comparative Example 1, the height of the alumina spheres filled in the cavity was greater than 80% of the target height, resulting in a target density lower than that obtained in Example 1. This indicates that a height of alumina spheres filled in the cavity greater than 80% of the target height is not conducive to improving the target density.

[0041] Comparative Example 2:

[0042] Its basic operation is the same as in Example 3, except that the height of the alumina ball is 1700mm and the bending deformation of the tubular target material above the ball is 2.0mm.

[0043] In Comparative Example 2, the length of the tubular target blank extending above the large sphere is greater than 1200 mm. The extended portion undergoes significant bending deformation after sintering, indicating that the height of the tubular target blank above the large sphere during initial sintering should be less than or equal to 1200 mm.

Claims

1. A sintering method for a long metal oxide tubular target, characterized in that: Includes the following steps: (1) A sintering plate (1) is placed in a sintering furnace. The sintering plate has a central air hole (12) in the middle. An annular air vent (11) is arranged on the sintering plate outside the central air hole. The annular air vent is composed of multiple small holes. (2) Place an annular enclosure (2) on the firing plate with the central vent hole as the center point, and the annular vent hole is located inside the annular enclosure; (3) Place a layer of small balls with a diameter of 0.5 to 3 mm on the firing plate between the central air hole and the air vent (4). (4) Place the tubular target blank (6) upright on the small ball (4); (5) The sleeve (3) is placed on the outside of the tubular target blank and erected on the annular enclosure. An annular cavity is formed between the sleeve and the tubular target blank. The annular cavity is located above the annular vent hole and communicates with the annular vent hole. (6) In the cavity formed between the sleeve and the tubular target blank, a large ball with a diameter greater than the small ball by 1.5 to 2 mm is filled (5). The diameter of the large ball is greater than the diameter of the small hole that makes up the vent hole. The height of the target is 50% ≤ the height of the large ball ≤ 80% of the height of the target. The height of the tubular target blank above the large ball is less than or equal to 1200 mm. (7) Then the tubular target is sintered in a sintering furnace.

2. The sintering method for a long metal oxide tubular target according to claim 1, characterized in that: The small and large spheres mentioned are alumina spheres or zirconium oxide spheres with a purity of not less than 99%.

3. The sintering method for a long metal oxide tubular target according to claim 1, characterized in that: The length of the tubular target blank is 1200mm to 6000mm.

4. The sintering method for a long metal oxide tubular target according to claim 1, characterized in that: The inner diameter of the annular enclosure is 5 to 25 mm larger than the outer diameter of the tubular target blank.

5. The sintering method for a long metal oxide tubular target according to claim 1, characterized in that: The diameter of the large sphere is 2 to 5 mm.

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