Coating method of rotary target material

Abstract

The invention belongs to the field of target material manufacturing, and discloses a coating method of a rotary target material. Comprising the following steps: (1) detecting a target material, cleaning the target material and drying the target material; (2) performing ultraviolet treatment on the inner wall of the target material; (3) mounting the target material to a coating clamp, and carrying out heat treatment on the target material in a drying oven; (4) the target material subjected to heat treatment and the coating clamp are placed in coating equipment together to be subjected to preheating treatment; (5) inert gas protection is started in a coating chamber of the coating equipment, and coating is started after the oxygen content is controlled to reach a set limit; and (6) detecting the coating effect of the target material, and carrying out repeated coating treatment on the substandard region until the target material is detected to be qualified. The coating method of the rotating target material has the advantages of being good in coating uniformity, high in production efficiency, high in process repeatability and the like, the adhesive force and reliability of the indium coating on the inner surface of the target material can be effectively improved, and the manufacturing cost increase caused by poor coating of the indium target material is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of target manufacturing and relates to a coating method for a rotating target. Background Technology

[0002] With the rapid development of the display panel and photovoltaic industries, the demand for ceramic sputtering targets is increasing, and their applications are becoming more and more widespread. Among ceramic sputtering targets, rotating targets are widely used in high-end coating processes due to their higher utilization rate and more uniform sputtering characteristics.

[0003] Coating the rotating target is a crucial step in the target bonding process, directly affecting the target bonding rate and the reliability of subsequent sputtering. Currently, traditional coating methods rely heavily on manual operation or semi-automatic equipment, resulting in uneven indium coating, low bonding rates between the target and the backing tube, and consequently, low target bonding yield, leading to higher manufacturing costs. Furthermore, the coating process requires heat treatment, typically above 160°C. Indium is prone to oxidation at high temperatures, leading to decreased coating purity, which in turn affects thermal conductivity and bonding strength, significantly reducing the target bonding yield. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the purpose of this invention is to provide a coating method for a rotating target, which realizes automated and precise coating, improves the uniformity and adhesion of the indium coating, effectively reduces the defect rate of the rotating target in the coating process, and significantly reduces production costs.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A coating method for a rotating target is provided, comprising the following steps:

[0007] (1) Inspect the target material, clean the target material and dry it;

[0008] (2) The inner wall of the target material is treated with ultraviolet light;

[0009] (3) Install the target material into the coating fixture and heat treat the target material in the oven;

[0010] (4) Place the heat-treated target material together with the coating fixture in the coating equipment for preheating treatment;

[0011] (5) Turn on the inert gas protection in the coating chamber of the coating equipment, control the oxygen content to the set limit and then start coating.

[0012] (6) Test the coating effect of the target material, and repeat the coating treatment multiple times for areas that do not meet the standard until the test is qualified.

[0013] As a preferred embodiment of a coating method for a rotating target, the coating equipment includes a main structure, an atmosphere control component, a coating fixture, a rotation drive component, a coating head positioning mechanism, a temperature control component, and a control system. The main structure includes a support platform with a chamber cover. When the chamber cover is placed on the support platform, a coating chamber is formed between the two. The atmosphere control component is disposed within the coating chamber and is used to adjust the ratio of reactive gas to inert gas within the coating chamber. The coating fixture is disposed within the coating chamber and is used for... The system includes a target clamp; a rotary drive assembly connected to the coating fixture for driving the coating fixture to rotate uniformly around the central axis of the target; a coating head positioning mechanism mounted on the support platform, connected to the coating head for driving the coating head to be accurately positioned in three-dimensional space, the coating head being used to coat the target with a coating layer; a temperature control assembly connected to the coating chamber for regulating the temperature inside the coating chamber; and a control system connected to the atmosphere control assembly, the rotary drive assembly, the coating head positioning mechanism, and the temperature control assembly.

[0014] As a preferred method for coating a rotating target, cleaning the target includes ultrasonic cleaning with deionized water for 10-60 minutes to remove surface impurities, followed by rinsing with acetone, anhydrous ethanol or isopropanol, and finally drying with oil-free compressed air.

[0015] The drying process involves drying at 80-120°C for 0.5-2 hours to completely remove residual solvent and moisture.

[0016] As a preferred embodiment of the coating method for the rotating target, the ultraviolet treatment wavelength is 180~380nm and the treatment time is 5~30 minutes.

[0017] As a preferred embodiment of the coating method for the rotating target, the heat treatment temperature is 150~250℃ and the holding time is 1~6 hours.

[0018] As a preferred embodiment of the coating method for the rotating target, the preheating temperature in the coating equipment is 100~200℃ and the time is 0.5~4 hours; during the preheating process, a mixture of ozone and oxygen gas can be filled into the coating chamber.

[0019] In a preferred embodiment of the coating method for a rotating target, the inert gas is nitrogen, argon, helium, or a mixture thereof.

[0020] In a preferred embodiment of the coating method for a rotating target, the oxygen content in the coating chamber is controlled to be below 10%.

[0021] In a preferred embodiment of the coating method for a rotating target, the oxygen content in the coating chamber is controlled to be below 5%.

[0022] As a preferred embodiment of the coating method for rotating targets, the coating method can simultaneously coat multiple targets in one coating chamber.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The rotating target coating method of this invention effectively improves the uniformity and bonding strength of indium coatings, reduces material loss during coating, and increases target bonding yield. Ultraviolet treatment of the inner wall of the target effectively removes surface organic contaminants and increases surface energy, enhancing the adhesion of subsequent coatings. The synergistic effect of heat treatment and preheating further optimizes the physical state of the target surface, ensuring uniform solvent evaporation during coating and reducing defect generation. Combined with inert gas protection and precise oxygen content control, oxidation reactions are suppressed, ensuring coating purity and density. The entire process utilizes an automated control system for precise parameter matching, significantly improving production efficiency and product consistency. Simultaneously, automated coating equipment allows for precise control of coating thickness, improving process stability and production efficiency, and reducing the risk of errors caused by human intervention. Preheating the equipment beforehand ensures the system reaches a stable operating temperature before coating operations, greatly improving coating efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic flowchart of the coating method for a rotating target according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of a coating device according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the coating fixture and target assembly according to an embodiment of the present invention.

[0029] Figure 4 for Figure 3 A schematic diagram of its breakdown.

[0030] Figure 5 This is a schematic diagram of the coating equipment according to another embodiment of the present invention.

[0031] Figure 6 This is a physical image of a target coated using the rotating target coating method of this invention.

[0032] Figure 7 The image shows the completed target coating after UV treatment, omitting the actual product.

[0033] Figure 8 This is a photograph of the target material coated without inert gas protection.

[0034] In the picture:

[0035] 1. Main structure; 11. Support platform; 12. Chamber cover; 2. Atmosphere control assembly; 3. Coating fixture; 31. Circular clamping plate; 311. Clearance hole; 312. Limiting groove; 32. Screw; 33. Nut; 4. Rotary drive assembly; 5. Coating head positioning mechanism; 6. Control system; 100. Target material; 110. Center hole. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0037] like Figure 1 As shown (and refer to the appendix) Figure 2-4 The present invention provides a coating method for a rotating target material, comprising the following steps: (1) inspecting the target material 100, cleaning the target material 100 and drying it; (2) subjecting the inner wall of the target material 100 (i.e., the hole wall of the central hole 110) to ultraviolet treatment; (3) installing the target material 100 to the coating fixture 3 and heat-treating the target material 100 in an oven; (4) placing the heat-treated target material 100 together with the coating fixture 3 in the coating equipment for preheating treatment; (5) turning on the inert gas protection in the coating chamber of the coating equipment, controlling the oxygen content to the set limit and then starting the coating; (6) inspecting the coating effect of the target material, and repeatedly coating the areas that do not meet the standards until the inspection is qualified.

[0038] like Figures 2 to 4As shown, the coating equipment used in the coating method for the rotating target of the present invention includes a main structure 1, an atmosphere control component 2, a coating fixture 3, a rotation drive component 4, a coating head positioning mechanism 5, a temperature control component, and a control system 6. The main structure 1 includes a support platform 11, on which a chamber cover 12 is disposed. When the chamber cover 12 is placed on the support platform 11, a coating chamber is formed between the two. The atmosphere control component 2 is disposed within the coating chamber and is used to adjust the ratio of reactive gas to inert gas within the coating chamber. The coating fixture 3 is disposed within the coating chamber. The coating fixture 3 is used to hold the target material 100. The rotary drive assembly 4 is connected to the coating fixture 3 and drives the coating fixture 3 to rotate uniformly around the central axis of the target material 100. The coating head positioning mechanism 5 is mounted on the support platform 11 and is connected to the coating head. The coating head positioning mechanism 5 drives the coating head to be accurately positioned in three-dimensional space. The coating head is used to coat the target material 100 with a coating. The temperature control assembly is connected to the coating chamber and is used to regulate the temperature inside the coating chamber. The control system 6 is connected to the atmosphere control assembly 2, the rotary drive assembly 4, the coating head positioning mechanism 5, and the temperature control assembly. Specifically, the rotary drive assembly 4 drives the target material 100 to rotate uniformly, the coating fixture 3 realizes the rapid clamping and positioning of the target material 100, the coating head positioning mechanism 5 ensures the accurate positioning of the coating head in three-dimensional space, the temperature control assembly regulates the temperature uniformity of the coating chamber, and the control system 6 integrates the coordinated operation of all components to achieve automated coating.

[0039] The coating fixture 3 includes two circular clamping plates 31 disposed at both ends of the target material 100 along its own axis. The two circular clamping plates 31 are connected by an adjustable clamping mechanism, which includes a screw 32, a nut 33, and an elastic washer. There are at least two screws 32, which surround the periphery of the target material 100, and each screw 32 is connected to a circular clamping plate 31 at both ends. At least one circular clamping plate 31 is movable relative to the screw 32. The movable circular clamping plate 31 is provided with a nut 33 and an elastic washer on the side away from the target material 100. The nut 33 is screwed onto the screw 32, and the elastic washer is sleeved on the outside of the screw 32 and clamped between the circular clamping plate 31 and the nut 33. The coating fixture 3 uses the combination of the nut 33 and the elastic washer to achieve flexible locking of the target material 100, which ensures the clamping firmness and avoids deformation or surface damage to the target material 100 caused by rigid clamping. Preferably, there is an even number of screws 32, and all screws 32 are evenly distributed in a ring on the circular clamping plate 31 along the central axis of the target material 100.

[0040] The target material 100 has a central hole 110 through it along its own axis. The coating fixture 3 clamps the target material 100 at both ends along the central axis of the target material 100. The coating fixture 3 has a clearance hole 311 that communicates with the central hole 110. Specifically, the clearance hole 311 is opened on the circular clamping plate 31. A through hole is opened on the wall of the coating chamber. This through hole connects the outside and the coating chamber. The through hole is directly opposite the clearance hole 311. The coating head on the coating head positioning mechanism 5 can pass through the through hole and the clearance hole 311 to coat the wall of the central hole 110 of the target material 100 with a coating.

[0041] Preferably, to better secure the target 100, a limiting groove 312 is recessed on one side of the circular clamping plate 31 facing the target 100. Both ends of the target 100 are inserted into the limiting grooves 312 of the two circular clamping plates 31 for simple positioning. A clearance hole 311 is provided at the bottom of the limiting groove 312 corresponding to the position of the center hole 110 of the target 100. More preferably, a rubber pad is provided in the limiting groove 312 except for the clearance hole 311, and a rubber pad is also provided on the groove wall of the limiting groove 312. The rubber pads buffer the contact points between the end face and outer peripheral surface of the target 100 and the limiting groove 312.

[0042] In addition, a support base is provided on the support platform 11, and the chamber cover 12 is rotatably mounted on the support base.

[0043] The above coating equipment can perform automated coating, improving the control accuracy of coating.

[0044] Example 1:

[0045] Reference Figure 2 As shown, in this embodiment of the invention, a coating is applied to a target material 100.

[0046] In practice, firstly, confirm that the target material 100 meets the specifications, such as color, size, density, resistivity, surface roughness, and inner wall roughness. Cleaning the target material 100 involves ultrasonic cleaning with deionized water for 30 minutes to remove surface impurities, followed by wiping and rinsing with isopropanol for 5 minutes, and then drying with oil-free compressed air. Next, the target material 100 is dried at 100°C for 1 hour to thoroughly remove residual solvents and moisture.

[0047] Then, the inner wall of the target 100 (i.e., the wall of the central hole 110) is subjected to ultraviolet (UV) treatment with a wavelength of 254 nm for 30 minutes. UV treatment can further decompose organic contaminants on the inner wall of the target 100 and increase surface energy to enhance coating adhesion.

[0048] Install the coating fixture 3, and place the target material 100 with the coating fixture 3 installed into a high-temperature oven for heat treatment. The heat treatment temperature is 220℃, and the holding time is 4 hours. Heat treatment can eliminate internal stress in the material and stabilize its physical properties.

[0049] After heat treatment, the target material 100, with the coating fixture 3 installed, is transferred to the coating equipment for preheating at 180℃ for 1 hour. During preheating, ozone gas is first introduced into the coating chamber at a flow rate of 10L / min for 10 minutes. This further removes organic matter, adsorbed trace gases, and residual moisture from the target surface, ensuring a clean coating environment. Throughout the preheating process, the target material 100's rotating device is activated at a speed of 5 rpm.

[0050] After preheating, the target 100 is rotated at 5 rpm while nitrogen gas is introduced into the coating chamber. The nitrogen gas is preheated within the same heating unit as the chamber before entering, ensuring that the incoming nitrogen gas maintains the same temperature as the chamber. Maintaining temperature consistency between the incoming nitrogen gas and the chamber effectively prevents thermal shock-induced stress defects in the coating. The nitrogen flow rate is controlled at 10 L / min, and after 30 minutes of continuous flow, the oxygen content in the chamber is reduced to below 10%, ensuring the coating process is carried out in a low-oxygen environment and minimizing the risk of oxidation.

[0051] It is important to note that indium, as a low-melting-point, highly ductile metal, requires strict control of the temperature gradient and atmosphere purity during coating to prevent surface oxidation or micro-diffusion. Its melting point is only 156.6℃, therefore, the temperature rise rate must be precisely controlled during heat treatment and coating to avoid localized overheating that could lead to deformation or flow. Furthermore, indium is extremely sensitive to oxygen; even trace amounts can form an insulating oxide layer, severely impacting coating adhesion strength and conductivity. Therefore, throughout the process, we use nitrogen to purge and effectively reduce the oxygen content in the chamber, ensuring an inert coating environment. Moreover, the indium oxide slag formed after indium oxidation is quite hard, which can easily lead to low adhesion rates in subsequent bonding processes, reducing the reliability of the target material.

[0052] Indium is poured onto the inner wall of the target 100, and then the coating head positioning mechanism 5 is activated to precisely move it to the starting coating position. The distance between the coating head and the inner wall of the target 100 is adjusted to 0.1~1mm, and the rotary drive assembly 4 is activated to keep the target 100 rotating at a uniform speed of 5rpm. At the same time, the heating unit maintains the temperature of the coating area at 180±5℃ to ensure that the molten indium is in an optimal flow state. The coating head moves uniformly along the axial direction at a speed of 1mm / s, and with the protection of a nitrogen atmosphere, a dense and continuous metal coating is formed. The distance sensing system monitors the change in the distance between the coating head and the inner wall of the target 100 in real time. After the entire inner wall of the target 100 has been coated in a single pass, the target 100 is removed and placed on a cooling rack, and the rotation speed of the target 100 is maintained at 2rpm. After the temperature drops to room temperature, the coating effect of the target 100 is confirmed. The indium coating on the inner wall of the target 100 must be uniform and continuous, without obvious discontinuities or pore defects, and without oxide residue. The target material 100 that passes the inspection is transferred to the next process for target material 100 bonding. The target material 100 that fails the coating inspection is coated again until it meets the specifications.

[0053] It should be noted that the coating method of this embodiment can sequentially coat multiple targets 100 in one coating chamber.

[0054] like Figure 6 As shown, in this embodiment, the coating method can effectively improve the density and adhesion of the coating on the target 100, prevent indium from oxidizing during high-temperature coating, and ensure the stability of the coating composition. By subjecting the target 100 to ultraviolet light treatment and inert gas protection during the coating process, organic contaminants on the inner wall of the target 100 are cleaned, improving the adhesion of the indium coating; in addition, the oxidation of indium to form hard oxide impurities is avoided, thereby significantly improving the bonding yield of the target 100 and reducing production costs. Figure 6 The image shown is a physical picture of the target 100 coated by the rotating target coating method of the present invention. As can be seen from the picture, the coating on the inner wall of the target 100 (i.e., the hole wall of the central hole 110) is uniform and free of oxide impurities.

[0055] Example 2:

[0056] See Figure 5 The process of the rotating target coating method provided in this embodiment is basically the same as that in Embodiment 1, except that: this solution sets up two coating heads and two coating head positioning mechanisms 5. The two coating head positioning mechanisms 5 are symmetrically arranged on both sides of the coating chamber, which can realize the simultaneous coating of the inner surfaces of two targets 100 in one coating chamber. The two sets of coating heads are driven by independent linear motors, and the closed-loop feedback system controls their positions and contact pressure respectively to ensure the independence and reliability of target coating.

[0057] The coating method implemented here can increase the coating efficiency of the target material and reduce equipment costs.

[0058] Example 3:

[0059] The process of the coating method for the rotating target provided in this embodiment is basically the same as that in Embodiment 1. The difference is that: this solution sets up four coating heads and four coating head positioning mechanisms 5. The four coating head positioning mechanisms 5 are symmetrically arranged on both sides of the coating chamber, so that the inner surface coating of four targets 100 can be realized simultaneously in the same coating chamber.

[0060] The coating apparatus of this embodiment can significantly increase the coating efficiency of the target material and reduce equipment costs.

[0061] Comparative Example 1:

[0062] To further verify the effectiveness of the coating method for the rotating target of the present invention, a comparative example 1 was set up. The coating method of this comparative example 1 did not include the ultraviolet treatment process for the target 100 in Example 1; other steps were consistent with Example 1. Upon testing, as... Figure 7 As shown ( Figure 7 (To omit the actual image of the target material after UV treatment), the coating adhesion of the target material 100 after UV treatment is significantly reduced, and there is obvious organic pollution residue on the inner wall of the target material 100, which weakens the bonding force between the indium coating and the substrate, and causes local peeling.

[0063] The results showed that the target material yield was improved by 10% and the bonding yield was improved by 20% by using ultraviolet treatment, thus improving the coating efficiency and reducing manufacturing costs.

[0064] Comparative Example 2:

[0065] To further verify the effectiveness of the coating method for the rotating target of the present invention, a comparative example 2 was set up. The coating method of this comparative example 2 does not include the inert gas protection process in example 1, and the other processes are consistent with those in example 1.

[0066] The results show that, Figure 8 As shown ( Figure 8 (This is a physical image of the target material coated without inert gas protection). Under this comparative process, the coating of target material 100 showed obvious oxidation marks, and the surface of the indium coating was rough with black oxides. The yield of target material 100 coated with inert gas protection was improved by 25%, the bonding yield was improved by 35%, the coating efficiency was improved, and the manufacturing cost was reduced.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A coating method for a rotating target, characterized in that: Includes the following steps: (1) Inspect the target material, clean the target material and dry it; (2) The inner wall of the target material is treated with ultraviolet light; (3) Install the target material into the coating fixture and heat treat the target material in the oven; (4) Place the heat-treated target material together with the coating fixture in the coating equipment for preheating treatment; (5) Turn on the inert gas protection in the coating chamber of the coating equipment, control the oxygen content to the set limit and then start coating. (6) Test the coating effect of the target material, and repeat the coating treatment multiple times for areas that do not meet the standard until the test is qualified.

2. The coating method for a rotating target according to claim 1, characterized in that: The coating equipment includes a main structure, an atmosphere control component, a coating fixture, a rotary drive component, a coating head positioning mechanism, a temperature control component, and a control system. The main structure includes a support platform with a chamber cover. When the chamber cover is placed on the support platform, a coating chamber is formed between the two. The atmosphere control component is located within the coating chamber and is used to adjust the ratio of reactive gas to inert gas within the coating chamber. The coating fixture is located within the coating chamber and is used to hold the target material. The rotary drive component... The moving component is connected to the coating fixture for driving the coating fixture to rotate uniformly around the central axis of the target material; the coating head positioning mechanism is disposed on the support platform and is connected to the coating head for driving the coating head to be accurately positioned in three-dimensional space, and the coating head is used to coat the target material with a coating layer; the temperature control component is connected to the coating chamber for regulating the temperature inside the coating chamber; the control system is connected to the atmosphere control component, the rotation drive component, the coating head positioning mechanism and the temperature control component respectively.

3. The coating method for a rotating target according to claim 1, characterized in that: Cleaning the target material involves ultrasonic cleaning with deionized water for 10-60 minutes to remove surface impurities, followed by rinsing with acetone, anhydrous ethanol or isopropanol, and finally drying with oil-free compressed air. The drying process involves drying at 80-120°C for 0.5-2 hours to completely remove residual solvent and moisture.

4. The coating method for the rotating target according to claim 1, characterized in that: The ultraviolet treatment wavelength is 180~380nm, and the treatment time is 5~30 minutes.

5. The coating method for a rotating target according to claim 1, characterized in that: The heat treatment temperature is 150~250℃, and the holding time is 1~6 hours.

6. The coating method for a rotating target according to claim 1, characterized in that: The preheating temperature in the coating equipment is 100~200℃, and the time is 0.5~4 hours. During the preheating process, a mixture of ozone and oxygen can be filled into the coating chamber.

7. The coating method for a rotating target according to claim 1, characterized in that: The inert gas is nitrogen, argon, helium, or a mixture thereof.

8. The coating method for a rotating target according to any one of claims 1 to 7, characterized in that: The oxygen content in the coating chamber is controlled to be below 10%.

9. The coating method for a rotating target according to claim 8, characterized in that: The oxygen content in the coating chamber is controlled to be below 5%.

10. The coating method for a rotating target according to any one of claims 1 to 7, characterized in that: The coating method allows for the simultaneous coating of multiple targets within a single coating chamber.

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