Nickel-vanadium alloy target assembly with good interface bonding strength and binding method of nickel-vanadium alloy target assembly

Abstract

The invention discloses a nickel-vanadium alloy target assembly with good interface bonding strength and a binding method of the nickel-vanadium alloy target assembly, and relates to the technical field of heterogeneous metal welding. The binding method specifically comprises the following steps that the nickel-vanadium alloy target material binding end face and the copper back plate binding end face are machined, the machined nickel-vanadium alloy target material binding end face is subjected to sand blasting treatment, and the nickel foil middle layer is subjected to surface activation; the activated nickel foil middle layer is placed between the end face for binding the machined copper back plate and the end face for binding the nickel-vanadium alloy target material subjected to sand blasting treatment, then diffusion welding connection is conducted, and a nickel-vanadium alloy target material assembly is obtained; the nickel foil intermediate layer is introduced, the activation process, the thickness and the microstructure of the nickel foil intermediate layer are optimized, meanwhile, sand blasting pretreatment is conducted on the surface of the nickel-vanadium target material, efficient diffusion and metallurgical bonding of interface elements are cooperatively achieved, and high-strength and high-welding-rate binding of the nickel-vanadium alloy target material assembly is achieved.

Description

Technical Field

[0001] This invention relates to a nickel-vanadium alloy target assembly with good interfacial bonding strength and its bonding method, belonging to the field of dissimilar metal welding technology. Background Technology

[0002] Sputtering targets are raw materials for physical vapor deposition (PVD) coatings. Compared to arc ion plating, vacuum evaporation coating, or other PVD coating methods, films prepared by sputtering have superior properties, such as dense film structure and uniform film thickness, making it one of the mainstream coating methods currently available. Nickel-vanadium alloy (NiV) is a widely used sputtering target. Containing 7% vanadium by mass, NiV is non-ferromagnetic, easy to deposit, and suitable for applications including adhesion layers in semiconductor devices and integrated circuits. However, the addition of vanadium to NiV also introduces new challenges to its preparation and processing, such as welding to backing materials.

[0003] To reduce costs and improve thermal conductivity, NiV alloys are typically welded to copper backing plates (a process known as bonding). Conventional welding methods primarily involve low-temperature brazing. However, the addition of V results in poor weldability of NiV alloys, and brazing is prone to cracking or porosity, leading to significant welding deformation and low productivity. Furthermore, the low melting point of the solder limits its use to temperatures below 200°C, restricting its further applications. Therefore, a more efficient welding method is needed.

[0004] Diffusion welding is a common method for preparing high-performance sputtering targets. Vacuum hot pressing and hot isostatic pressing methods are used to tightly bond the workpieces together. Under certain temperature and pressure, the two contacting surfaces are held for a certain time, and the diffusion of atoms on the welding surface achieves a reliable connection between the target and the copper backing plate. However, during the diffusion welding bonding process, because vanadium (V) is easily oxidized, oxygen enrichment is likely to occur during welding, thus affecting the welding strength and performance of the nickel-vanadium alloy and the copper backing plate. Patent document CN104690417A discloses a welding method for nickel or nickel alloy targets and backing plates. By machining uniformly distributed straight teeth on the surface of the nickel-vanadium alloy, hot isostatic pressing can achieve a target assembly with a welding rate of 98.5% and a welding strength of 156 MPa. However, its surface processing is time-consuming, the hot isostatic pressing process is complex and requires high-end equipment, and the welding rate and strength do not reach optimal levels.

[0005] Adding an intermediate layer to weld targets is a method already in use. For example, US patent document US6619537B1 deposits a nickel alloy layer on the surface of a copper target and an aluminum backing plate, and then prepares a Cu / Al backing plate target assembly by hot isostatic pressing. This method requires a long time for depositing the nickel alloy and requires specialized coating equipment, and hot isostatic pressing is expensive, which obviously increases the cost for mass industrial production.

[0006] Therefore, it is necessary to develop a low-cost, high-efficiency nickel-vanadium sputtering target assembly with good interfacial bonding strength and its welding method. Summary of the Invention

[0007] To address the shortcomings of related technologies, this invention provides a nickel-vanadium alloy target assembly with good interfacial bonding strength and its bonding method. It has the advantages of achieving high strength and high welding rate in connecting the nickel-vanadium alloy target to the copper backing plate, and solves the problems of low welding bonding strength and complex operation between the nickel-vanadium alloy target and the copper backing plate.

[0008] One of the objectives of this invention is to provide a nickel-vanadium alloy target assembly with good interfacial bonding strength, wherein the nickel-vanadium alloy target assembly is composed of a nickel-vanadium alloy target, a nickel foil interlayer and a copper backing plate, and the interfacial shear strength is ≥190MPa.

[0009] Preferably, the vanadium content in the nickel-vanadium alloy target is 7±0.5% by mass; the copper backing plate is oxygen-free copper (such as Tu1) or copper alloy backing plate (such as copper-chromium alloy, copper-chromium-zirconium alloy, copper-zinc alloy).

[0010] Preferably, the nickel foil interlayer is in a rolled or annealed state, and the thickness of the nickel foil interlayer is 25~500μm. When the nickel foil interlayer is in a rolled state, the average width of the rolled grains is less than 50μm, and when the nickel foil interlayer is in an annealed state, the average grain size is less than 50μm.

[0011] More preferably, the thickness of the nickel foil interlayer is 50~200μm; when the nickel foil interlayer is in a rolled state, its grains are flat and the average width perpendicular to the rolling direction is less than 50μm.

[0012] The second objective of this invention is to provide a method for bonding nickel-vanadium alloy target components with good interfacial bonding strength, specifically including the following steps: (1) The end face for bonding the nickel-vanadium alloy target and the end face for bonding the copper back plate are machined respectively (preferably by turning or grinding) to obtain the machined nickel-vanadium alloy target and the machined copper back plate.

[0013] (2) The end face of the nickel-vanadium alloy target material after machining is sandblasted to obtain the sandblasted nickel-vanadium alloy target material.

[0014] (3) Surface activation of the nickel foil intermediate layer is performed to obtain the activated nickel foil intermediate layer.

[0015] (4) The activated nickel foil intermediate layer is placed between the mechanically processed copper back plate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face, and then diffusion welding is performed to obtain a nickel-vanadium alloy target assembly with good interface bonding strength.

[0016] Preferably, the conditions for sandblasting in step (2) are as follows: using white corundum or silicon carbide sand, sandblasting is performed for 2 to 10 minutes at a sandblasting distance of 100 to 200 mm and a sandblasting pressure of 0.3 to 0.6 MPa; the roughness of the nickel-vanadium alloy target after sandblasting is 2 to 6 μm.

[0017] Preferably, the surface activation method in step (3) is to immerse the intermediate layer of the nickel foil in a hydrochloric acid aqueous solution or a sulfuric acid aqueous solution with a mass percentage concentration of 2-10% for 1-10 minutes.

[0018] Preferably, the diffusion welding conditions in step (4) are: vacuum hot pressing sintering, under vacuum conditions, with a pressure of 10~50MPa and a temperature of 400~650℃, vacuum hot pressing for 1~4h.

[0019] More preferably, the vacuum degree of the vacuum hot pressing in step (4) is 1.0 × 10⁻⁶. -1 ~1.0×10 -2 Pa.

[0020] Mechanism of the invention: This invention utilizes a sandblasting process to treat the surface of a nickel-vanadium alloy target, combined with the synergistic effect of a nickel foil interlayer. This process removes the surface oxide layer while simultaneously creating a uniform micro-rough structure on the nickel-vanadium alloy surface. This not only increases the specific surface area but also further removes residual impurities and enhances surface atomic activity, thereby promoting atomic diffusion during the welding process. Finally, under the synergistic effect of vacuum hot pressing, a strong metallurgical bond is achieved at the interface, significantly improving the overall bonding strength.

[0021] The beneficial effects of this invention are: This invention, by introducing a nickel foil interlayer and optimizing its activation process, thickness, and microstructure, along with pre-blasting treatment of the nickel-vanadium target, synergistically achieves efficient diffusion and metallurgical bonding of interfacial elements. This significantly improves the purity and smoothness of the welding interface, reduces the interfacial oxygen content, and results in a nickel-vanadium alloy target assembly with an interfacial shear strength ≥190 MPa. This method effectively overcomes the problem of interfacial failure due to insufficient bonding strength during direct welding or brazing, greatly improves the bonding performance and yield of the target, and is simple to operate, effectively reducing the manufacturing cost of the target assembly.

[0022] The introduction of nickel foil in the nickel-vanadium alloy target assembly of this invention is key to achieving good interfacial bonding strength. Firstly, the nickel interlayer enables effective connection between the nickel-vanadium target and the copper and copper backing plate, reducing welding failures during use due to low bonding strength caused by direct welding or brazing methods. Secondly, nickel foil is widely available and inexpensive, effectively improving production efficiency.

[0023] This invention uses a nickel foil intermediate layer with a thickness of 25~500μm to achieve effective connection between the nickel-vanadium target and the copper and copper backing plate; in addition, this invention uses nickel foil with a fine and controllable grain size, which accelerates the interdiffusion between the nickel foil and the nickel-vanadium and copper backing plate during the welding process.

[0024] The purpose of sandblasting in this invention is not to significantly increase the surface roughness of the target material. On the contrary, the purpose of sandblasting is to obtain a surface roughness of the target material that facilitates the diffusion of elements between the nickel-vanadium and nickel foil interlayer during the bonding process.

[0025] This invention activates the intermediate layer of nickel foil to enhance the activation energy of the nickel surface during welding. By activating the surface of the intermediate layer of nickel foil, the surface smoothness of the nickel foil can be improved, surface contaminants can be reduced, and the bonding strength between the nickel foil and the substrate can be enhanced.

[0026] This invention requires welding through heating, pressurization, and heat preservation. The vacuum hot pressing method has low equipment requirements, significantly simplifies the process, reduces production costs, and is more suitable for large-scale production scenarios. Attached Figure Description

[0027] Figure 1 Figure (a) shows the SEM morphology and EDS elemental distribution of the interface between the nickel-vanadium and copper backplate after welding in Example 1 of the present invention, and Figure (b) shows the EDS elemental distribution.

[0028] Figure 2 Figure 1 shows the TEM elemental analysis of the interface between nickel, vanadium and copper backplate after welding in Comparative Example 1 of this invention. Figure (a) is the distribution map of oxygen (O); Figure (b) is the distribution map of vanadium (V); and Figure (c) is the TEM bright-field image of the interface region. Detailed Implementation

[0029] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. In the embodiments and comparative examples of this invention, unless otherwise specified, all chemical reagents used were commercially available analytical grade reagents. The vanadium content in the nickel-vanadium alloy targets used in the embodiments and comparative examples of this invention is 7% by mass.

[0030] Example 1 A method for preparing a nickel-vanadium alloy target assembly with good interfacial bonding strength specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target and the end face of the Tu1 oxygen-free copper backplate were machined by grinding respectively to obtain the machined nickel-vanadium alloy target and Tu1 oxygen-free copper backplate with a diameter of 100 mm and a thickness of 4 mm.

[0031] (2) The end face of the nickel-vanadium alloy target material after machining was sandblasted with white corundum sand to remove oxide scale. The sandblasting distance was 100 mm, the sandblasting pressure was 0.3 MPa, and the sandblasting time was 10 min. The average surface roughness of the sandblasted nickel-vanadium alloy target material was measured to be 2 μm.

[0032] (3) Immerse a 25 μm thick annealed nickel foil (average grain size of 5 μm) in a 10% hydrochloric acid aqueous solution for 1 min to obtain an activated nickel foil intermediate layer.

[0033] (4) The activated nickel foil interlayer is placed between the machined Tu1 oxygen-free copper backplate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face. Then, the Tu1 oxygen-free copper backplate, nickel foil interlayer, and nickel-vanadium alloy target are diffusion welded together by vacuum hot pressing. The welding temperature is 450℃, the welding pressure is 50MPa, and the vacuum degree is 1.0×10 -2 At Pa, vacuum hot pressing for 2 hours yields a nickel-vanadium alloy target assembly with good interfacial bonding strength.

[0034] The performance of the nickel-vanadium alloy target assembly prepared in this embodiment was tested. The specific methods were as follows: SEM was used to observe the morphology and elemental distribution of the nickel-vanadium alloy bonding end face; a roughness meter was used to measure the surface roughness of the nickel-vanadium alloy after sandblasting; ultrasonic scanning was used to test the welding rate of the target after welding; samples were prepared according to the national standard (GB / T39163-2020) for the test method of the bonding strength between the target and the backing plate; and a universal testing machine was used to test the shear strength of the welded surface. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Example 1 was 100%, and the shear strength of the welded surface (i.e., the interfacial shear strength) was 190 MPa. The SEM image of the nickel-vanadium alloy target assembly prepared in Example 1 (as shown in Table 1) is also included. Figure 1 (a) shown) and EDS element distribution map (as shown) Figure 1 As shown in (b), except for a few pores, the interface between the NiV alloy and the copper backing plate is flat, achieving excellent diffusion welding. This embodiment, by introducing a nickel foil interlayer and optimizing its activation process, thickness, and microstructure, while simultaneously performing sandblasting pretreatment on the nickel-vanadium target, synergistically achieves efficient diffusion and metallurgical bonding of interface elements, significantly improving the purity and smoothness of the welding interface and reducing the interface oxygen content. This embodiment effectively overcomes the problem of interface failure easily caused by insufficient bonding strength during direct welding or brazing, greatly improving the bonding performance of the target material.

[0035] Example 2 A method for preparing a nickel-vanadium alloy target assembly with good interfacial bonding strength specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target and the end face of the copper-chromium alloy back plate were machined by turning respectively to obtain the machined nickel-vanadium alloy target and copper-chromium alloy back plate (Cu-0.5Cr alloy back plate) with a diameter of 254 mm and a thickness of 6.35 mm.

[0036] (2) The end face of the nickel-vanadium alloy target material after machining was sandblasted with silicon carbide sand to remove oxide scale. The sandblasting distance was 150 mm, the sandblasting pressure was 0.45 MPa, and the sandblasting time was 5 min. The average surface roughness of the sandblasted nickel-vanadium alloy target material was measured to be 3.2 μm.

[0037] (3) A 150 μm thick rolled nickel foil (with an average grain width of 20 μm) was immersed in a 2% sulfuric acid aqueous solution for 10 min to obtain an activated nickel foil intermediate layer.

[0038] (4) The activated nickel foil interlayer is placed between the machined copper-chromium alloy backplate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face. Then, the copper-chromium alloy backplate, nickel foil interlayer, and nickel-vanadium alloy target are diffusion welded together by vacuum hot pressing. The welding temperature is 550℃, the welding pressure is 30MPa, and the vacuum degree is 3.0×10 -2 At Pa, vacuum hot pressing for 3 hours yields a nickel-vanadium alloy target assembly with good interfacial bonding strength.

[0039] Using the same testing methods as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Example 2 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Example 2 was 100%, and the interfacial shear strength was 200 MPa. The SEM and EDS elemental distribution diagrams of the nickel-vanadium alloy target assembly prepared in Example 2 show that the interface between the NiV alloy and the copper backing plate is straight, achieving excellent diffusion welding. This example, by introducing a nickel foil interlayer and optimizing its activation process, thickness, and microstructure, along with pre-blasting treatment of the nickel-vanadium target, synergistically achieved efficient diffusion and metallurgical bonding of interfacial elements, significantly improving the purity and smoothness of the welding interface and reducing the interfacial oxygen content. This example effectively overcomes the problem of interface failure easily caused by insufficient bonding strength during direct welding or brazing, and greatly improves the bonding performance of the target.

[0040] Example 3 A method for preparing a nickel-vanadium alloy target assembly with good interfacial bonding strength specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target and the end face of the copper-zinc alloy back plate are machined by turning respectively to obtain the machined nickel-vanadium alloy target and copper-zinc alloy back plate (H70 brass back plate) with a diameter of 300 mm and a thickness of 8 mm.

[0041] (2) The end face of the nickel-vanadium alloy target material after machining was sandblasted with white corundum sand to remove oxide scale. The sandblasting distance was 200 mm, the sandblasting pressure was 0.6 MPa, and the sandblasting time was 2 min. The average surface roughness of the sandblasted nickel-vanadium alloy target material was measured to be 5.8 μm.

[0042] (3) Immerse a 50 μm thick annealed nickel foil (average grain size of 5 μm) in a 5% hydrochloric acid aqueous solution for 5 min to obtain an activated nickel foil intermediate layer.

[0043] (4) The activated nickel foil interlayer is placed between the machined copper-zinc alloy backplate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face. Then, the copper-zinc alloy backplate, nickel foil interlayer, and nickel-vanadium alloy target are diffusion welded together by vacuum hot pressing. The welding temperature is 650℃, the welding pressure is 10MPa, and the vacuum degree is 1.0×10 -1 At Pa, vacuum hot pressing for 4 hours yields a nickel-vanadium alloy target assembly with good interfacial bonding strength.

[0044] Using the same testing methods as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Example 3 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Example 3 was 100%, and the interfacial shear strength was 220 MPa. The SEM and EDS elemental distribution diagrams of the nickel-vanadium alloy target assembly prepared in Example 3 show that the interface between the NiV alloy and the copper backing plate is straight, achieving excellent diffusion welding. This example, by introducing a nickel foil interlayer and optimizing its activation process, thickness, and microstructure, along with pre-blasting treatment of the nickel-vanadium target, synergistically achieved efficient diffusion and metallurgical bonding of interfacial elements, significantly improving the purity and smoothness of the welding interface and reducing the interfacial oxygen content. This example effectively overcomes the problem of interface failure easily caused by insufficient bonding strength during direct welding or brazing, greatly improving the bonding performance of the target.

[0045] Example 4 A method for preparing a nickel-vanadium alloy target assembly with good interfacial bonding strength specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target and the end face of the copper-chromium-zirconium alloy back plate were machined by turning respectively to obtain a machined nickel-vanadium alloy target and a copper-chromium-zirconium alloy back plate (C18150 alloy back plate) with a diameter of 440 mm and a thickness of 11 mm.

[0046] (2) The end face of the nickel-vanadium alloy target material after machining was sandblasted with white corundum sand to remove oxide scale. The sandblasting distance was 200 mm, the sandblasting pressure was 0.6 MPa, and the sandblasting time was 10 min. The sandblasted nickel-vanadium alloy target material was obtained, and its average surface roughness was measured to be 6.0 μm.

[0047] (3) Immerse a 500 μm thick annealed nickel foil (average grain size of 20 μm) in a 10% hydrochloric acid aqueous solution for 3 min to obtain an activated nickel foil intermediate layer.

[0048] (4) The activated nickel foil interlayer is placed between the machined copper-chromium-zirconium alloy backplate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face. Then, the copper-chromium-zirconium alloy backplate, nickel foil interlayer, and nickel-vanadium alloy target are diffusion welded together by vacuum hot pressing. The welding temperature is 400℃, the welding pressure is 50MPa, and the vacuum degree is 5.0×10 -2 At Pa, vacuum hot pressing for 2 hours yields a nickel-vanadium alloy target assembly with good interfacial bonding strength.

[0049] Using the same testing methods as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Example 4 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Example 4 was 100%, and the interfacial shear strength was 250 MPa. The SEM and EDS elemental distribution diagrams of the nickel-vanadium alloy target assembly prepared in Example 4 show that the interface between the NiV alloy and the copper backing plate is straight, achieving excellent diffusion welding. This example, by introducing a nickel foil interlayer and optimizing its activation process, thickness, and microstructure, while simultaneously performing sandblasting pretreatment on the nickel-vanadium target, synergistically achieved efficient diffusion and metallurgical bonding of interfacial elements, significantly improving the purity and smoothness of the welding interface and reducing the interfacial oxygen content. This example effectively overcomes the problem of interface failure easily caused by insufficient bonding strength during direct welding or brazing, and greatly improves the bonding performance of the target.

[0050] Comparative Example 1 A method for preparing a nickel-vanadium alloy target assembly specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target for bonding is machined by turning to obtain a machined nickel-vanadium alloy target with a diameter of 100 mm, a thickness of 4 mm, and a surface roughness of 10 μm.

[0051] (2) The end face of the Tu1 copper backing plate with a diameter of 100 mm and a thickness of 4 mm is tightly bonded to the end face of the machined nickel-vanadium alloy target. Then, the copper backing plate and the nickel-vanadium alloy target are diffusion welded together by vacuum hot pressing. The welding temperature is 450℃, the welding pressure is 50 MPa, and the vacuum degree is 1.0×10 -2 At Pa, vacuum hot pressing for 1 hour yields a nickel-vanadium alloy target assembly.

[0052] The performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 1 was tested using the same testing method as in Example 1. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Comparative Example 1 was 93.8%, and the interfacial shear strength was 79 MPa. TEM elemental analysis diagram of the nickel-vanadium alloy target assembly prepared in Comparative Example 1 is shown in Table 1. Figure 2As can be seen from (a~c), due to the direct welding of NiV and copper backing without sandblasting, a large amount of oxygen is enriched at the interface between nickel vanadium and copper backing, resulting in a decrease in welding rate and lower strength.

[0053] Comparative Example 2 A method for preparing a nickel-vanadium alloy target assembly specifically includes the following steps: (1) The end face of the nickel-vanadium alloy target for bonding is machined by turning to obtain a machined nickel-vanadium alloy target with a diameter of 100 mm and a thickness of 4 mm.

[0054] (2) A nickel film was sputtered on the bonding end face of the machined nickel-vanadium alloy target by magnetron sputtering. The thickness of the nickel film was 25 μm and the time was 20 h. The nickel-vanadium alloy target after magnetron sputtering was obtained. The nickel film peeled off after sputtering.

[0055] (3) The end face of the Tu1 copper back plate with a diameter of 100 mm and a thickness of 4 mm is tightly bonded to the end face of the nickel-vanadium alloy target material after magnetron sputtering. Then, the copper back plate and the nickel-vanadium alloy target material are welded together by hot isostatic pressing. The welding temperature is 500℃, the welding pressure is 100MPa, and the hot isostatic pressing time is 2h to obtain the nickel-vanadium alloy target material assembly.

[0056] Using the same testing method as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 2 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Comparative Example 2 was 93.2%, and the interfacial shear strength was 116 MPa. Comparative Example 2 used a nickel film as an intermediate layer. It took a long time to prepare a nickel film of the same thickness, and the film was prone to peeling when thickened, resulting in a lower welding rate and welding strength.

[0057] Comparative Example 3 A method for preparing a nickel-vanadium alloy target assembly differs from Example 2 in that the nickel-vanadium target blank is not de-scaled by sandblasting, while the other steps are the same.

[0058] Using the same testing method as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 3 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Comparative Example 3 was 94.9%, and the interfacial shear strength was 82 MPa. Since Comparative Example 3 did not perform sandblasting on the nickel-vanadium cross-section, the oxide layer on the target blank surface was not removed, and a uniform micro-rough structure on the target blank surface was not constructed, resulting in poor atomic diffusion effect during the welding process, and low welding rate and welding strength.

[0059] Comparative Example 4 A method for preparing a nickel-vanadium alloy target assembly differs from Example 3 in that the thickness of the nickel foil used is 2000 μm, while the other steps are the same. After welding, cracks appeared at the interface between the target and the copper backing plate.

[0060] Using the same testing method as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 4 was tested. The performance test results are shown in Table 1. The nickel-vanadium alloy target assembly prepared in Comparative Example 4 cracked at the interface, which made it impossible to weld the nickel-vanadium alloy target assembly. This was because the nickel foil intermediate layer used in Comparative Example 4 was too thick, resulting in greater stress. The interface between the target and the backing plate cracked directly after welding, and effective welding was not achieved.

[0061] Comparative Example 5 A method for preparing a nickel-vanadium alloy target assembly differs from Example 4 in that the nickel foil surface is not activated, while the remaining steps are the same.

[0062] Using the same testing method as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 5 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Comparative Example 5 was 96%, and the interfacial shear strength was 105 MPa. This is because the nickel foil in Comparative Example 5 was not activated, resulting in poor surface finish of the nickel foil and failure to enhance the surface activation energy of the nickel during the welding process, leading to a lower welding rate and welding strength.

[0063] Comparative Example 6 A method for preparing a nickel-vanadium alloy target assembly differs from Example 4 in that the average grain size of the nickel foil used is 500 μm, while the other steps are the same.

[0064] Using the same testing method as in Example 1, the performance of the nickel-vanadium alloy target assembly prepared in Comparative Example 6 was tested. The performance test results are shown in Table 1. The welding rate of the nickel-vanadium alloy target assembly prepared in Comparative Example 6 was 98%, and the interfacial shear strength was 104 MPa. This is because the grain size of the intermediate layer of nickel foil used in Comparative Example 6 was too large, which led to a decrease in welding rate and welding strength.

[0065] Table 1 The differences in welding rate and welding strength between the above embodiments and comparative examples fully demonstrate that the method provided by the present invention, through the synergistic effect of adding nickel foil as an intermediate layer and activating and sandblasting the nickel foil, has excellent performance in preparing nickel-vanadium target components with high welding rate and good bonding strength.

[0066] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A nickel-vanadium alloy target assembly with good interfacial bonding strength, characterized in that, The nickel-vanadium alloy target assembly consists of a nickel-vanadium alloy target, a nickel foil intermediate layer, and a copper backing plate, with an interfacial shear strength ≥190MPa.

2. The nickel-vanadium alloy target assembly with good interfacial bonding strength according to claim 1, characterized in that, The vanadium content in the nickel-vanadium alloy target is 7±0.5% by mass; the copper backing plate is oxygen-free copper or copper alloy backing plate.

3. The nickel-vanadium alloy target assembly with good interfacial bonding strength according to claim 1, characterized in that, The nickel foil intermediate layer is in a rolled or annealed state, and the thickness of the nickel foil intermediate layer is 25~500μm. When the nickel foil intermediate layer is in a rolled state, the average width of the rolled grains is less than 50μm, and when the nickel foil intermediate layer is in an annealed state, the average grain size is less than 50μm.

4. The bonding method for a nickel-vanadium alloy target assembly with good interfacial bonding strength as described in claim 1, characterized in that, Specifically, the following steps are included: (1) The end face for bonding the nickel-vanadium alloy target and the end face for bonding the copper back plate are machined respectively to obtain the machined nickel-vanadium alloy target and the machined copper back plate. (2) The end face of the nickel-vanadium alloy target material after machining is sandblasted to obtain the sandblasted nickel-vanadium alloy target material. (3) Surface activation of the nickel foil intermediate layer is performed to obtain the activated nickel foil intermediate layer; (4) The activated nickel foil intermediate layer is placed between the mechanically processed copper back plate bonding end face and the sandblasted nickel-vanadium alloy target bonding end face, and then diffusion welding is performed to obtain a nickel-vanadium alloy target assembly with good interface bonding strength.

5. The bonding method for a nickel-vanadium alloy target assembly with good interfacial bonding strength according to claim 4, characterized in that, The conditions for sandblasting in step (2) are as follows: white corundum or silicon carbide sand is used, and sandblasting is performed for 2 to 10 minutes at a sandblasting distance of 100 to 200 mm and a sandblasting pressure of 0.3 to 0.6 MPa; the roughness of the nickel-vanadium alloy target after sandblasting is 2 to 6 μm.

6. The bonding method for a nickel-vanadium alloy target assembly with good interfacial bonding strength according to claim 4, characterized in that, The surface activation method in step (3) is as follows: immerse the intermediate layer of the nickel foil in a hydrochloric acid aqueous solution or sulfuric acid aqueous solution with a mass percentage concentration of 2~10% for 1~10 minutes.

7. The bonding method for a nickel-vanadium alloy target assembly with good interfacial bonding strength according to claim 4, characterized in that, The conditions for diffusion welding in step (4) are: vacuum hot pressing sintering, under vacuum conditions, with a pressure of 10~50MPa and a temperature of 400~650℃, vacuum hot pressing for 1~4h.

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