Sintering method of long metal oxide tubular target material

Abstract

The invention relates to a sintering method of a long metal oxide tubular target material, which comprises the following steps of: placing a setter plate in a sintering furnace, arranging a central air hole and an annular air hole on the setter plate, placing an annular enclosure on the setter plate, paving a layer of small balls on the setter plate between the central air hole and the air hole, vertically placing a tubular target material blank on the small balls, and sintering the tubular target material blank on the annular enclosure, the tubular target material blank is sleeved with a sleeve, the sleeve stands on the annular fence, an annular cavity communicated with the annular air holes is formed between the sleeve and the tubular target material blank, the annular cavity is filled with large balls, and then the tubular target material is sintered. According to the method, the spherical refractory material is adopted to support the bottom and the outer circumference of the tubular target biscuit, the sintering atmosphere is diffused through the gaps formed between the balls, the method can be used for sintering the tubular target with the length larger than or equal to 1200 mm, the bending deformation of the tubular target obtained through sintering is smaller than or equal to 0.5 mm, deformation is small, the sintering quality is good, and the method is suitable for industrial production. And the method is suitable for batch production of long metal oxide tubular target materials.

Description

Technical Field

[0001] The invention relates to a target material sintering method, in particular to a sintering method of a long metal oxide tubular target material. Background Art

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

[0003] Existing metal oxide tubular targets are mostly made of several sections spliced ​​together. The presence of splicing seams will affect the quality of coating. Increasing the length of a single section of tubular target and reducing the splicing seams is an industry trend. However, ultra-long tubular targets, such as tubular target blanks with a length of ≥1200mm, are prone to large bending deformation during sintering, resulting in the inability to produce targets of suitable sizes. Therefore, it is necessary to develop a sintering method suitable for ultra-long tubular target blanks with a length of ≥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 material, in which a sphere is used to support the outer wall of the tubular target material blank, and when the tubular target material shrinks during the sintering process, the sphere can also always contact the outer wall of the tubular target material to provide supporting force for the target material. The tubular target material sintered by this method has small deformation and good sintering quality.

[0005] The technical solution to the above technical problem is: a sintering method of a long metal oxide tubular target, comprising the following steps: (1) placing a setter plate in a sintering furnace, wherein a central air hole is opened in the middle of the setter plate, and an annular air hole is arranged on the setter plate outside the central air hole, wherein the annular air hole is composed of a plurality of small holes; (2) placing an annular enclosure on the setter plate with the central air hole as the center point, and the annular air 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 support plate between the central pore and the air vent; (4) placing the tubular target blank upright on the ball; (5) The sleeve is placed on the outer side of the tubular target blank and stands on the annular enclosure, and an annular cavity is formed between the sleeve and the tubular target blank, and the annular cavity is located above the annular vent hole and communicated with the annular vent hole; (6) A large ball having a diameter 1.5 to 2 mm larger than the small ball is filled into the cavity formed between the sleeve and the tubular target body, and the diameter of the large ball is larger than the diameter of the small hole constituting the air vent; (7) The tubular target is then sintered in a sintering furnace.

[0006] Furthermore, in step (6), the target material height 50% ≤ the large ball height ≤ the target material height 80%, and the height of the tubular target material blank above the large ball is less than or equal to 1200 mm.

[0007] Furthermore, the small balls and large balls are alumina balls or zirconia balls with a purity of not less than 99%.

[0008] Furthermore, the length of the tubular target blank is 1200 mm to 6000 mm.

[0009] Furthermore, the inner diameter of the annular enclosure is 5 to 25 mm larger than the outer diameter of the tubular target blank.

[0010] Furthermore, the diameter of the large ball is 2 to 5 mm.

[0011] The present invention lays a layer of small balls with a diameter of 0.5 to 3 mm on a support plate, places a tubular target blank on the small balls, and then sleeves the outside of the tubular target blank. Then, large balls with a diameter of 1.5 to 2 mm larger than the small balls are filled between the tubular target blank and the sleeve, that is, the large balls with a diameter of 2 to 5 mm are used to support the outer wall of the tubular target blank. During the sintering process, when the tubular target shrinks inwardly, the cavity between the tubular target blank and the sleeve is enlarged, and the large balls move downward under the action of their own gravity, and can always contact the outer wall of the tubular target to provide support for the target. The present invention adopts spherical refractory materials to support the bottom and outer circumference of the tubular target blank, and utilizes the gaps formed between the balls to diffuse the sintering atmosphere. The present invention can be used for sintering of tubular target blanks with a length of ≥1200 mm. Since there are relatively large pores between the spheres, the diffusion of the sintering atmosphere is convenient, and the outer circumference of the tubular target is supported and is not prone to large bending. The bending deformation of the sintered tubular target is ≤0.5 mm, the deformation is small, and the sintering quality is good. The present invention is suitable for mass production of long-sized metal oxide tubular targets.

[0012] The technical features of a sintering method for a long metal oxide tubular target of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 : Schematic diagram of the supporting state of the tubular target material during sintering of the present invention.

[0014] Figure 2 : Schematic diagram of the bottom support during sintering of the tubular target material of the present invention.

[0015] Figure 3 : Figure 2 AA section view.

[0016] Figure 4 : A bottom view of the support plate used in the present invention.

[0017] In the figure: 1-sintering plate, 11-annular air hole, 12-central air hole, 13-air outlet, 2-annular enclosure, 3-sleeve, 4-small ball, 5-large ball, 6-tubular target blank. DETAILED DESCRIPTION

[0018] To better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be understood by those skilled in the art that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Example 1

[0020] By cold isostatic pressing, an ITO tubular target blank with a length of 1200mm, a wall thickness of 14mm and an inner diameter of 160mm is formed. A support plate with a central air hole is placed in a sintering furnace, and an annular air hole is opened around the central air hole, and the annular air hole is composed of multiple small holes. On the support plate, an annular enclosure is placed with the central air hole as the center point of the circle. The annular air hole is located in the annular enclosure, and the inner diameter of the annular enclosure is 25mm larger than the outer diameter of the tubular target blank. A layer of alumina balls with a diameter of 3mm is laid on the support plate between the central air hole and the air hole. The tubular target blank with a length of 1200mm is placed upright on the alumina balls with a diameter of 3mm.

[0021] A refractory sleeve that can withstand the sintering temperature is placed outside the tubular target blank and stands on the annular enclosure. An annular cavity is formed between the sleeve and the target, and the annular cavity is located above the annular vent hole and communicates with the annular vent hole. Alumina balls with a diameter of 5 mm are filled in the annular cavity. The height of the alumina balls is 960 mm, and the diameter of the alumina balls is larger than the diameter of the small holes that constitute the vent hole.

[0022] Then the target was sintered in a sintering furnace at a temperature of 1600°C for 8 hours. The bending deformation of the sintered tubular target in the length direction was 0.5 mm, and the target density was 7.13 g / cm 3 .

[0023] Example 2

[0024] By cold isostatic pressing, an ITO tubular blank with a length of 1200 mm, a wall thickness of 14 mm, and an inner diameter of 160 mm is formed. A support plate with a central air hole is placed in a sintering furnace, and an annular air hole is opened around the central air hole, and the annular air hole is composed of multiple small holes. On the support plate, an annular enclosure is placed with the central air hole as the center point of the circle. The annular air hole is located inside the annular enclosure, and the inner diameter of the annular enclosure is 5 mm larger than the outer diameter of the tubular target blank. A layer of alumina balls with a diameter of 0.5 mm is laid on the support plate between the central air hole and the air hole. The tubular target blank with a length of 1200 mm is placed upright on the alumina balls with a diameter of 0.5 mm.

[0025] A refractory sleeve that can withstand the sintering temperature is placed outside the tubular target blank and stands on the annular enclosure. An annular cavity is formed between the sleeve and the target, and the annular cavity is located above the annular vent hole and is connected to the annular vent hole. Alumina balls with a diameter of 2 mm are filled in the annular cavity. The height of the alumina balls is 900 mm, and the diameter of the alumina balls is larger than the diameter of the small holes that constitute the vent hole.

[0026] Then the target was sintered in a sintering furnace at a temperature of 1500°C for 10 hours. The bending deformation of the sintered tubular target in the length direction was 0.4 mm, and the target density was 7.09 g / cm 3 .

[0027] Example 3

[0028] By cold isostatic pressing, an ITO tubular blank with a length of 3000 mm, a wall thickness of 15 mm, and an inner diameter of 170 mm is formed. A support plate with a central air hole is placed in a sintering furnace, and an annular air hole is opened around the central air hole, and the annular air hole is composed of multiple small holes. On the support plate, an annular enclosure is placed with the central air hole as the center point of the circle. The annular air hole is located inside the annular enclosure, and the inner diameter of the annular enclosure is 15 mm larger than the outer diameter of the tubular target blank. A layer of alumina balls with a diameter of 1 mm is laid on the support plate between the central air hole and the air hole. The tubular target blank with a length of 1500 mm is placed upright on the alumina balls with a diameter of 1 mm.

[0029] A refractory sleeve that can withstand the sintering temperature is placed outside the tubular target blank and stands on the annular enclosure. An annular cavity is formed between the sleeve and the target, and the annular cavity is located above the annular vent hole and communicates with the annular vent hole. Alumina balls with a diameter of 3 mm are filled in the annular cavity. The height of the alumina balls is 2000 mm, and the diameter of the alumina balls is larger than the diameter of the small holes that constitute the vent hole.

[0030] Then it was sintered in a sintering furnace at a sintering temperature of 1550°C for 12 hours. The bending deformation of the sintered tubular target in the length direction was 0.5 mm, and the target density was 7.12 g / cm 3 .

[0031] Comparative Example 1: The basic operation is the same as that of Example 1, except that the height of the alumina ball is 1000 mm, the bending deformation of the sintered tubular target in the length direction is 0.5 mm, and the target density is 7.01 g / cm 3 .

[0032] In Comparative Example 1, the height of the large alumina balls filled in the cavity is greater than 80% of the target material height, so that the final target material density is lower than the target material density obtained in Example 1, indicating that when the height of the large alumina balls filled in the cavity is greater than 80% of the target material height, it is not conducive to improving the target material density.

[0033] Comparative Example 2: The basic operation is the same as that of Example 3, except that the height of the large alumina ball is 1700 mm, and the bending deformation of the sintered tubular target material above the large ball is 2.0 mm.

[0034] In comparative example 2, the length of the tubular target blank above the large ball is greater than 1200 mm, and the protruding portion has a large bending deformation after sintering, indicating that the height of the tubular target blank above the large ball during initial sintering should be less than or equal to 1200 mm.

Claims

1. A method for sintering a long metal oxide tubular target, characterized in that: The following steps are involved: (1) placing a setter plate (1) in a sintering furnace, wherein a central air hole (12) is opened in the middle of the setter plate, and an annular air hole (11) is arranged on the setter plate outside the central air hole, wherein the annular air hole is composed of a plurality of small holes; (2) placing an annular enclosure (2) on the setter plate with the central air hole as the center point, and the annular air hole is located inside the annular enclosure; (3) placing a layer of small balls (4) with a diameter of 0.5 to 3 mm on the support plate between the central pore and the air holes; (4) placing the tubular target blank (6) upright on the small ball (4); (5) The sleeve (3) is placed on the outer side of the tubular target material blank and stands on the annular enclosure, wherein an annular cavity is formed between the sleeve and the tubular target material blank, and the annular cavity is located above the annular vent hole and communicates with the annular vent hole; (6) Filling a large ball (5) having a diameter 1.5 to 2 mm larger than that of the small ball into the cavity formed between the sleeve and the tubular target material blank, wherein the diameter of the large ball is larger than the diameter of the small hole constituting the air vent; (7) The tubular target is then sintered in a sintering furnace.

2. The sintering method of a long metal oxide tubular target according to claim 1, characterized in that: In step (6), the target material height 50% ≤ the large ball height ≤ the target material height 80%, and the height of the tubular target material blank above the large ball is less than or equal to 1200 mm.

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

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

5. The sintering method of 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.

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

Images