Preparation method of high-purity copper tube target material for panel display

Abstract

The invention provides a preparation method of a high-purity copper tube target for panel display, which comprises the following steps: firstly, changing the internal organization structure of a high-purity copper ingot through forging and stretching deformation, then controlling the extrusion temperature, reducing the total cross sectional area of an extruded product, and increasing the extrusion coefficient to 5-8, thereby effectively crushing the grain structure and obtaining smaller grains; and finally, low-temperature annealing is carried out after drawing, stress can be removed, the hardness cannot be reduced, the grain size cannot be changed and is smaller than or equal to 100 micrometers, the optimal grain size can reach 50-80 micrometers, and therefore the high-purity copper pipe target material for panel display can be obtained. The preparation method disclosed by the invention is simple to operate, the stability of the product is ensured, and mass production can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of high-purity copper tube target materials for flat panel displays, and in particular to a method for preparing a high-purity copper tube target material for flat panel displays. Background Art

[0002] In the electrode wiring of thin film transistors used in liquid crystal display devices such as flat panel displays, aluminum electrodes or copper electrodes formed by sputtering are mainly used. In comparison, copper has better electrical properties than aluminum. In recent years, with the development trend and requirements of large-scale, high-resolution and high-speed driving frequency of liquid crystal display terminals, copper wires with low resistivity and good electromigration ability are increasingly used in TFT arrays.

[0003] Target materials are mainly divided into plane targets and tube targets. The target material is made into a tube with a stationary magnet inside. The tube target rotates at a certain speed during sputtering, so it is also called a rotating target. Compared with plane targets, tube targets have the characteristics of high utilization rate and uniform coating composition, and are the standard material in the field of sputtering coating.

[0004] At present, the prior art discloses some methods for preparing high-purity copper tube targets. For example, CN115433907A discloses a hot extrusion method for preparing a copper target for sputtering thin film coating technology, wherein the production of the copper tube target includes: a cast copper ingot (purity of at least 99.99% copper, oxygen not exceeding 5ppm) formed by hot extrusion and cold drawing. The control of grain size is based on the dynamic recrystallization mechanism. Therefore, the hot copper is immediately cooled with water during extrusion of the extrusion die. This technology is called underwater extrusion technology, which will stop the grain growth mechanism. However, this technology involves underwater operation, has high requirements for production equipment, and increases production costs. CN117548631A discloses a copper tube preparation device and method for tube targets. The technical solution focuses on disclosing a copper tube preparation device for tube targets. The device can prepare copper tubes in one step, shorten the preparation process, reduce preparation costs, and improve preparation efficiency, precision and purity. However, directly casting high-purity copper liquid into copper tubes for tube targets will result in problems such as substandard hardness, density, and grains. CN112846660A and CN112981335A respectively disclose a method for preparing a high-purity copper tube target, which mainly includes: extruding, annealing, machining and other processes a high-purity copper ingot with a copper content of more than 99.99% to obtain a high-purity copper tube target. However, the existing copper tube target technology has too high a temperature, the grains are difficult to control, the technology is complex, and errors are prone to occur.

[0005] In summary, it is necessary to develop a new method for preparing high-purity copper tube targets for flat panel displays. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for preparing a high-purity copper tube target for flat panel display, wherein the preparation method first changes the internal structure of the high-purity copper ingot by forging and stretching deformation, then controls the extrusion temperature, reduces the total cross-sectional area of ​​the extruded product, increases the extrusion coefficient to 5-8, effectively breaks the grain structure, obtains smaller grains, and finally performs low-temperature annealing after drawing, which can remove stress without reducing hardness, and the grain size will not change, ≤100μm, and optimally can reach 50-80μm, thereby obtaining a high-purity copper tube target for flat panel display. The preparation method of the present invention is simple to operate, ensures the stability of the product, and can achieve mass production.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The object of the present invention is to provide a method for preparing a high-purity copper tube target for a flat panel display, the preparation method comprising the following steps:

[0009] (1) performing a first machining process on a high-purity copper ingot to obtain a high-purity copper ingot having a target size;

[0010] (2) subjecting the high-purity copper ingot of step (1) to first high-temperature preheating, forging and stretching, and peeling and boring in sequence to obtain a copper ingot blank;

[0011] (3) subjecting the copper ingot blank of step (2) to second high-temperature preheating, hole expansion, third high-temperature preheating, and extrusion in sequence to obtain a crude copper tube;

[0012] (4) The crude copper tube of step (3) is sequentially subjected to drawing, low temperature annealing, straightening, and second machining to obtain a high-purity copper tube target for flat panel displays.

[0013] The preparation method of the present invention first changes the internal structure of the high-purity copper ingot by forging and stretching deformation, then controls the extrusion temperature, reduces the total cross-sectional area of ​​the extruded product, increases the extrusion coefficient to 5-8, effectively breaks the grain structure, obtains smaller grains, and finally performs low-temperature annealing after drawing, which can remove stress without reducing hardness and changing the grain size, thereby obtaining a high-purity copper tube target for flat panel display. The preparation method of the present invention is simple to operate, ensures the stability of the product, and can achieve mass production.

[0014] It should be noted that the hole expansion in step (3) of the present invention can make the diameter of the hole in the middle of the copper ingot blank reach the required size very accurately.

[0015] As a preferred technical solution of the present invention, in step (1), the first machining includes: peeling the high-purity copper ingot and then cutting it into the required weight.

[0016] Preferably, in step (1), the height / diameter of the high-purity copper ingot is less than 2.5.

[0017] As a preferred technical solution of the present invention, in step (2), the target temperature of the first high-temperature preheating is 800-900°C, for example, 800°C, 810°C, 830°C, 850°C, 870°C, 880°C or 900°C, and the insulation time is 2-4h, for example, 2h, 2.5h, 3h, 3.5h or 4h, etc.

[0018] Preferably, in step (2), the forging ratio of the forging deformation is 1-2, such as 1, 1.1, 1.3, 1.5, 1.6, 1.8 or 2.

[0019] As a preferred technical solution of the present invention, in step (3), the target temperature of the second high-temperature preheating is 700-750°C, for example, 700°C, 710°C, 720°C, 730°C, 740°C or 750°C, and the insulation time is 3-5h, for example, 3h, 3.5h, 4h, 4.5h or 5h.

[0020] As a preferred technical solution of the present invention, in step (3), the target temperature of the third high-temperature preheating is 700-750°C, for example, 700°C, 710°C, 720°C, 730°C, 740°C or 750°C, and the insulation time is 1.5-2h, for example, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, etc.

[0021] Preferably, in step (3), the extrusion temperature is 700-750°C, for example, 700°C, 710°C, 720°C, 730°C, 740°C or 750°C, and the extrusion rate is 15-18mm / s, for example, 15mm / s, 15.5mm / s, 16mm / s, 16.5mm / s, 17mm / s, 17.5mm / s or 18mm / s, etc.

[0022] As a preferred technical solution of the present invention, before drawing in step (4), the excess parts at both ends of the crude copper tube are removed, and then the tube is immersed in acid solution for 1-2 hours for pickling, and finally the defective position is ground to prepare for the drawing.

[0023] It should be noted that the pickling described in the present invention is to remove the oxide layer on the surface of the crude copper tube, and the subsequent grinding can use a grinder to grind the defective position.

[0024] As a preferred technical solution of the present invention, in step (4), the drawing includes a first drawing and a second drawing performed in sequence. After two drawing steps, the outer diameter is reduced, the inner diameter is increased, and the deformation amount and wall thickness are controlled to achieve the desired size and tube strength.

[0025] Preferably, the first drawing method is cold drawing, which reduces the outer diameter, increases the inner diameter, and thins the wall thickness. Based on the initial wall thickness of the crude copper tube, the deformation amount is 5-7%, such as 5%, 5.5%, 6%, 6.5% or 7%.

[0026] Preferably, the second drawing method is cold drawing, which reduces the outer diameter, increases the inner diameter, and thins the wall thickness. Based on the wall thickness of the tube obtained by the first drawing, the deformation amount is 5-7%, such as 5%, 5.5%, 6%, 6.5% or 7%.

[0027] As a preferred technical solution of the present invention, in step (4), the temperature of the low-temperature annealing is 225-255°C, for example, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C or 255°C.

[0028] As a preferred technical solution of the present invention, in step (4), the straightening makes the straightness of the copper tube ≤1mm / m.

[0029] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0030] (1) The high-purity copper ingot is peeled, then cut into required weights, and the first machining is completed to obtain a high-purity copper ingot with a height / diameter less than 2.5;

[0031] (2) using an electric heating furnace to preheat the high-purity copper ingot of step (1) at 800-900° C. for 2-4 hours, forging and stretching to achieve a forging ratio of 1-2, and then peeling and boring to obtain a copper ingot blank;

[0032] (3) using an electric heating furnace to heat the copper ingot blank of step (2) at 700-750° C. for 3-5 hours for a second high-temperature preheating, placing it in an electric heating furnace to continue to heat after hole expansion, and heat it at 700-750° C. for 1.5-2 hours for a third high-temperature preheating, transferring the copper material to an extruder for extrusion, controlling the extrusion temperature to 700-750° C., and the extrusion rate to 15-18 mm / s, and quickly placing the copper tube blank obtained by high-temperature extrusion into cold water for cooling to obtain a crude copper tube;

[0033] (4) removing the excess parts at both ends of the crude copper tube in step (3), then immersing it in an acid solution for 1-2 hours for pickling, and finally grinding the defective position with a grinder to prepare for subsequent drawing; using a drawing machine to perform a first drawing and a second drawing in sequence, wherein the first drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the initial wall thickness of the crude copper tube as a reference, and the deformation amount is 5-7%; the second drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the wall thickness of the tube obtained by the first drawing as a reference, and the deformation amount is 5-7% to achieve the required size and tube body strength, and the drawn copper tube is low-temperature annealed at 225-255°C, and then straightened so that the straightness of the copper tube is ≤1mm / m, and a second machining is performed according to the target size to obtain a high-purity copper tube target for flat panel displays.

[0034] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0035] The preparation method of the present invention improves the fluidity of the metal inside the copper tube by expanding the hole, increasing the extrusion coefficient, controlling the extrusion temperature, increasing the deformation amount, effectively breaking the grain structure, and then low-temperature annealing to ensure the uniformity of the internal metal structure. The operation is simple, the stability of the product is guaranteed, and mass production can be achieved. DETAILED DESCRIPTION

[0036] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0037] Example 1

[0038] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display, the preparation method comprising the following steps:

[0039] (1) The high-purity copper ingot is peeled, then cut into required weights, and the first machining is completed to obtain a high-purity copper ingot with a height / diameter less than 2.5;

[0040] (2) using an electric heating furnace to preheat the high-purity copper ingot of step (1) at 850° C. for 3 h, forging and stretching to achieve a forging ratio of 1.5, and then peeling and boring to obtain a copper ingot blank;

[0041] (3) using an electric heating furnace to keep the copper ingot blank of step (2) at 730° C. for 4 h for a second high-temperature preheating, placing it in an electric heating furnace to continue keeping it warm after hole expansion, keeping it at 730° C. for 1.8 h for a third high-temperature preheating, transferring the copper material to an extruder for extrusion, controlling the extrusion temperature to 730° C., the extrusion rate to 16 mm / s, and quickly placing the copper tube blank obtained by high-temperature extrusion into cold water for cooling to obtain a crude copper tube;

[0042] (4) removing the excess parts at both ends of the crude copper tube in step (3), then immersing it in an acid solution for 1.5 hours for pickling, and finally grinding the defective position with a grinder to prepare for subsequent drawing; using a drawing machine to perform a first drawing and a second drawing in sequence, wherein the first drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the initial wall thickness of the crude copper tube as a reference, and the deformation amount is 6%; the second drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the wall thickness of the tube obtained by the first drawing as a reference, and the deformation amount is 6% to achieve the required size and tube body strength, and the drawn copper tube is low-temperature annealed at 240°C, and then straightened so that the straightness of the copper tube is ≤1mm / m, and a second machining is performed according to the target size to obtain a high-purity copper tube target for flat panel displays.

[0043] Example 2

[0044] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display, the preparation method comprising the following steps:

[0045] (1) The high-purity copper ingot is peeled, then cut into required weights, and the first machining is completed to obtain a high-purity copper ingot with a height / diameter less than 2.5;

[0046] (2) using an electric heating furnace to preheat the high-purity copper ingot of step (1) at 800° C. for 4 h, forging and stretching to achieve a forging ratio of 1, and then peeling and boring to obtain a copper ingot blank;

[0047] (3) using an electric heating furnace to keep the copper ingot blank of step (2) at 700° C. for 5 h for a second high-temperature preheating, placing it in an electric heating furnace to continue keeping it warm after the hole expansion is completed, keeping it at 700° C. for 2 h for a third high-temperature preheating, transferring the copper material to an extruder for extrusion, controlling the extrusion temperature to 700° C., the extrusion rate to 15 mm / s, and quickly placing the copper tube blank obtained by high-temperature extrusion into cold water for cooling to obtain a crude copper tube;

[0048] (4) removing the excess parts at both ends of the crude copper tube in step (3), then immersing it in an acid solution for 1 hour for pickling, and finally grinding the defective position with a grinder to prepare for subsequent drawing; using a drawing machine to perform a first drawing and a second drawing in sequence, wherein the first drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the initial wall thickness of the crude copper tube as a reference and the deformation amount being 5%, and the second drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the wall thickness of the tube obtained by the first drawing as a reference and the deformation amount being 5%, to achieve the required size and tube body strength, and the drawn copper tube is low-temperature annealed at 225° C., and then straightened so that the straightness of the copper tube is ≤1 mm / m, and a second machining is performed according to the target size to obtain a high-purity copper tube target for flat panel displays.

[0049] Example 3

[0050] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display, the preparation method comprising the following steps:

[0051] (1) The high-purity copper ingot is peeled, then cut into required weights, and the first machining is completed to obtain a high-purity copper ingot with a height / diameter less than 2.5;

[0052] (2) using an electric heating furnace to preheat the high-purity copper ingot of step (1) at 900° C. for 2 h, forging and stretching to achieve a forging ratio of 2, and then peeling and boring to obtain a copper ingot blank;

[0053] (3) using an electric heating furnace to keep the copper ingot blank of step (2) at 750° C. for 3 h for a second high-temperature preheating, placing it in an electric heating furnace to continue keeping it warm after the hole expansion is completed, keeping it at 750° C. for 1.5 h for a third high-temperature preheating, transferring the copper material to an extruder for extrusion, controlling the extrusion temperature to 750° C., and the extrusion rate to 18 mm / s, and quickly placing the copper tube blank obtained by high-temperature extrusion into cold water for cooling to obtain a crude copper tube;

[0054] (4) removing the excess parts at both ends of the crude copper tube in step (3), then immersing it in an acid solution for 2 hours for pickling, and finally grinding the defective position with a grinder to prepare for subsequent drawing; using a drawing machine to perform a first drawing and a second drawing in sequence, wherein the first drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the initial wall thickness of the crude copper tube as a reference, and the deformation amount is 7%; the second drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the wall thickness of the tube obtained by the first drawing as a reference, and the deformation amount is 7% to achieve the required size and tube body strength, and the drawn copper tube is low-temperature annealed at 255° C., and then straightened so that the straightness of the copper tube is ≤1 mm / m, and a second machining is performed according to the target size to obtain a high-purity copper tube target for flat panel displays.

[0055] Example 4

[0056] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Embodiment 1, the only difference is that the extrusion temperature in step (3) is reduced to 650°C.

[0057] Example 5

[0058] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Embodiment 1, the only difference is that the extrusion temperature in step (3) is increased to 800°C.

[0059] Example 6

[0060] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Embodiment 1, the only difference is that in step (4), the deformation amount of the first drawing and the second drawing are both reduced to 4%.

[0061] Example 7

[0062] This embodiment provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Embodiment 1, the only difference is that the deformation amount of the first drawing and the second drawing in step (4) are both increased to 8%.

[0063] Comparative Example 1

[0064] This comparative example provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Example 1, the only difference is that the hole expansion described in step (3) is omitted.

[0065] Comparative Example 2

[0066] This comparative example provides a method for preparing a high-purity copper tube target for a flat panel display. Compared with Example 1, the only difference is that the second drawing in step (4) is completely omitted and only the first drawing is performed.

[0067] After the second machining in the above-mentioned embodiments and comparative examples, the processed edge materials were taken to test the hardness, density and grain size respectively. The specific test results are shown in Table 1.

[0068] Table 1

[0069] project Hardness / HV Density Grain size / μm Example 1 97.3 99.95％ 60.3 Example 2 94.3 99.96％ 65.5 Example 3 96.6 99.94％ 75.3 Example 4 103.5 99.93％ 32.1 Example 5 96.6 99.92％ 130.2 Example 6 73.3 99.94％ 58.4 Example 7 105.2 99.92％ 70.3 Comparative Example 1 95.6 99.93％ 100.1 Comparative Example 2 74.3 99.92％ 55.3

[0070] It can be seen from Table 1 that:

[0071] (1) The preparation method of the present invention improves the fluidity of the metal inside the copper tube by expanding the hole, increasing the extrusion coefficient, controlling the extrusion temperature, increasing the deformation, effectively breaking the grain structure, and then low-temperature annealing to ensure the uniformity of the internal metal structure, so that the hardness of the prepared high-purity copper tube target for flat panel display is greater than 95HV, the density is greater than 99.9%, and the grain size is 60-80μm. The operation is simple, the stability of the product is guaranteed, and mass production can be achieved;

[0072] (2) Comparing Example 1 with Examples 4 and 5, since Example 4 lowers the extrusion temperature to 650°C, the grain size is significantly reduced to only 32.1 μm. Since Example 5 raises the extrusion temperature to 800°C, the grains grow abnormally, and the grain size increases to 130.2 μm.

[0073] (3) Comparing Example 1 with Examples 6 and 7, since Example 6 reduces the deformation of the first and second drawing to 4%, the hardness is significantly reduced to only 73.3 HV. Since Example 7 increases the deformation of the first and second drawing to 8%, the hardness and grain size are increased, but not significantly.

[0074] (4) Comparing Example 1 with Comparative Example 1, since the hole expansion is completely omitted in Comparative Example 1, the fluidity of the metal inside the copper tube is poor, and the grain size increases to 100.1 μm;

[0075] (5) Comparing Example 1 with Comparative Example 2, since the second drawing is completely omitted in Comparative Example 2 and only the first drawing is performed, the hardness is significantly reduced to only 74.3 HV, and the grain size is also significantly reduced to only 55.3 μm.

[0076] The present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a high-purity copper tube target for flat panel display, characterized in that: The preparation method comprises the following steps: (1) performing a first machining on the high-purity copper ingot to obtain a high-purity copper ingot having a target size; (2) subjecting the high-purity copper ingot of step (1) to first high-temperature preheating, forging and stretching, and peeling and boring in sequence to obtain a copper ingot blank; (3) subjecting the copper ingot blank of step (2) to second high-temperature preheating, hole expansion, third high-temperature preheating, and extrusion in sequence to obtain a crude copper tube; (4) The crude copper tube of step (3) is sequentially subjected to drawing, low temperature annealing, straightening, and second machining to obtain a high-purity copper tube target for flat panel display.

2. The preparation method according to claim 1, characterized in that: In step (1), the first machining process includes: peeling the high-purity copper ingot and then cutting it into required weights; Preferably, in step (1), the height / diameter of the high-purity copper ingot is less than 2.

5.

3. The preparation method according to claim 1 or 2, characterized in that: In step (2), the target temperature of the first high temperature preheating is 800-900°C, and the holding time is 2-4h; Preferably, in step (2), the forging ratio of the forging deformation is 1-2.

4. The preparation method according to any one of claims 1 to 3, characterized in that In step (3), the target temperature of the second high-temperature preheating is 700-750°C, and the insulation time is 3-5h.

5. The preparation method according to any one of claims 1 to 4, characterized in that: In step (3), the target temperature of the third high temperature preheating is 700-750°C, and the holding time is 1.5-2h; Preferably, in step (3), the extrusion temperature is 700-750° C., and the extrusion rate is 15-18 mm / s.

6. The preparation method according to any one of claims 1 to 5, characterized in that: Before the drawing in step (4), the crude copper tube is removed from the two ends of the residual parts, and then immersed in acid solution for 1-2 hours for pickling, and finally the defective position is ground to prepare for the drawing.

7. The preparation method according to any one of claims 1 to 6, characterized in that: In step (4), the drawing includes a first drawing and a second drawing performed sequentially; Preferably, the first drawing method is cold drawing, which reduces the outer diameter, increases the inner diameter, and thins the wall thickness. The deformation is 5-7% based on the initial wall thickness of the crude copper tube; Preferably, the second drawing method is cold drawing, which reduces the outer diameter, increases the inner diameter, and thins the wall thickness. The deformation is 5-7% based on the wall thickness of the tube obtained by the first drawing.

8. The preparation method according to any one of claims 1 to 7, characterized in that: In step (4), the temperature of the low temperature annealing is 225-255°C.

9. The preparation method according to any one of claims 1 to 8, characterized in that: In step (4), the straightening is performed so that the straightness of the copper tube is ≤1 mm / m.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) peeling the high-purity copper ingot, cutting it into the required weight, and completing the first machining to obtain a high-purity copper ingot with a height / diameter less than 2.5; (2) using an electric heating furnace to preheat the high-purity copper ingot of step (1) at 800-900° C. for 2-4 hours, forging and stretching to achieve a forging ratio of 1-2, and then peeling and boring to obtain a copper ingot blank; (3) using an electric heating furnace to heat the copper ingot blank of step (2) at 700-750° C. for 3-5 hours for a second high-temperature preheating, placing it in an electric heating furnace to continue to heat after hole expansion, and heat it at 700-750° C. for 1.5-2 hours for a third high-temperature preheating, transferring the copper material to an extruder for extrusion, controlling the extrusion temperature to 700-750° C., and the extrusion rate to 15-18 mm / s, and quickly placing the copper tube blank obtained by high-temperature extrusion into cold water for cooling to obtain a crude copper tube; (4) removing the excess parts at both ends of the crude copper tube in step (3), then immersing it in an acid solution for 1-2 hours for pickling, and finally grinding the defective position with a grinder to prepare for subsequent drawing; using a drawing machine to perform a first drawing and a second drawing in sequence, wherein the first drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the initial wall thickness of the crude copper tube as a reference, and the deformation amount is 5-7%; the second drawing method is cold drawing, reducing the outer diameter, increasing the inner diameter, and thinning the wall thickness, with the wall thickness of the tube obtained by the first drawing as a reference, and the deformation amount is 5-7% to achieve the required size and tube body strength, and the drawn copper tube is low-temperature annealed at 225-255°C, and then straightened so that the straightness of the copper tube is ≤1mm / m, and a second machining is performed according to the target size to obtain a high-purity copper tube target for flat panel displays.