Precious metal sputtering target

Abstract

The utility model discloses a precious metal sputtering target which comprises a target material body and a back plate arranged on the bottom face of the target material body, the target material body is provided with an annular protruding structure and a connecting part, the annular protruding structure is in mirror symmetry with the sputtering etching morphology, the center of the annular protruding structure is the highest part, and the center of the annular protruding structure gradually transits to the edge in a saddle shape. The connecting part is in a plane shape, and the back plate is welded to the target material body. According to the precious metal sputtering target, the annular convex structure which is in mirror symmetry with the sputtering etching morphology is formed on the target body, so that the convex part is excited in the sputtering process, the initial overall thickness of the target is greatly reduced, and the utilization rate of the target is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of precious metal sputtering target technology, specifically to a precious metal sputtering target. Background Technology

[0002] Vacuum magnetron sputtering is widely used for surface coating of products, offering advantages such as being environmentally friendly, producing excellent film performance, and allowing for a wide range of film types. Among these, precious metal sputtering coating is an important type of coating material, widely used in aerospace, information technology, electronics, biomedicine, and decorative industries. To date, sputtering coatings in the decorative field mostly utilize planar targets. During sputtering, argon gas is ionized by impact, and the argon ions, under bias voltage, bombard the target surface at high speed, forming an etching layer. Because electrons are confined near the target surface, forming a ring-shaped etching zone of a certain width, the deepest etching occurs at the center of the zone. The etching gradually decreases in depth towards both sides, forming a racetrack-shaped etching groove resembling a wide, shallow pit. Other parts of the target surface are rarely etched. However, once the center of the etching groove is etched through, the target material becomes unusable. Therefore, the utilization rate of this planar target material is less than 30%, which also affects the coating quality. For precious metals, this low utilization rate significantly increases coating costs. It requires peeling the target material from the copper backing plate, sending it to a specialized refining plant for purification and recycling, and then using pure precious metals and intermediate alloys to formulate the target material. These processing steps all involve the loss of precious metals and processing costs. Therefore, how to quickly repair the target surface with high quality without affecting the coating quality has become a pressing problem for the industry. A few researchers have conducted related research and achieved some results. For example, the patent "A Repair Method for Sputtering Targets" uses a 3D scanner to scan the etching grooves on the target surface to determine its etching morphology, and then uses CNC machining to repair the target. Patent CN1608141A discloses a repair method for discarded sputtering targets, which uses hot isostatic pressing or HIP technology to fill the loss area of ​​the target with new sputtering target material to repair the discarded sputtering target.

[0003] The aforementioned existing technologies primarily address the issue of refining targets after use. While they improve target utilization to some extent, the following problems remain: First, the initial investment in targets is high. Because the targets are traditional planar targets with uniform thickness across all parts, and to achieve a longer service life, the initial thickness cannot be too thin. This leads to a significant increase in the precious metal weight of the target, greatly increasing the initial investment and capital costs for enterprises. For the jewelry industry, which is dominated by small and medium-sized enterprises, such an excessively large initial investment is unbearable. Second, the refining rate of targets is limited. Each refining operation only fills the etched groove area, and the etched area already accounts for a small percentage of the total volume. Therefore, the cost-effectiveness of refining is not significantly better than manufacturing new targets, and is even more complex than manufacturing new targets. For example, accurately obtaining the shape of the etched groove and creating a perfectly matching restoration is a very difficult task, as the etched grooves on the target after use are irregular, and processing a well-matched restoration requires high precision.

[0004] Studies have shown that rotating targets can significantly improve target utilization. However, existing coating equipment is based on planar targets, and modifying it to a rotating target structure presents significant technical challenges and requires substantial investment. Furthermore, rotating targets are difficult to manufacture. Moreover, during sputtering, the entire target surface exhibits numerous glow rings, preventing the formation of continuous banded glow and affecting the uniformity of the film. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, this utility model provides a precious metal sputtering target, which solves the above-mentioned traditional problems.

[0006] This utility model is achieved using the following technical solution:

[0007] A precious metal sputtering target includes a target body and a back plate disposed on the bottom surface of the target body. The target body has an annular protrusion structure and a connecting portion that are mirror-symmetrical to the sputtering etch morphology. The center of the annular protrusion structure is the highest part, and the center of the annular protrusion structure gradually transitions to the edge in a saddle shape. The connecting portion is planar, and the back plate is welded to the target body.

[0008] Preferably, the thickness of the connecting portion is controlled at 2-3 mm, and the highest part of the annular protrusion structure is 5-10 mm higher than the connecting portion.

[0009] Preferably, the target body is divided into a top target block, a bottom target block, and several middle target blocks, wherein the thickness and width of the top target block, the bottom target block, and the middle target blocks are all the same.

[0010] Preferably, the number of intermediate target blocks is 6 to 12.

[0011] Preferably, the top target block surface is provided with a first arc-shaped protrusion, the bottom target block surface is provided with a second arc-shaped protrusion, and the middle target block surface is provided with a straight protrusion.

[0012] Preferably, the top target block, bottom target block, and middle target block are seamlessly spliced ​​together to form a continuous target surface.

[0013] Preferably, the bottom surface of the target body is a plane, the side of the back plate connected to the target body is a plane, and the target body and the back plate are in close contact.

[0014] Preferably, the back plate is a copper back plate.

[0015] Preferably, an indium solder paste layer is provided between the back plate and the target body.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. The precious metal sputtering target of this utility model forms an annular protrusion structure on the target body that is mirror-symmetrical to the sputtering etching morphology, so that the sputtering process is excited at the protrusion, thereby greatly reducing the initial overall thickness of the target material and significantly improving the utilization rate of the target material.

[0018] 2. The precious metal sputtering target of this utility model divides the target body into a top target block, a bottom target block and several middle target blocks. By seamlessly splicing the target blocks, a continuous target surface can be formed, and a continuous strip glow can be formed during the sputtering process, ensuring the uniformity and quality of the coating layer. Attached Figure Description

[0019] Figure 1 This is a structural view of the precious metal sputtering target of this utility model;

[0020] Figure 2 for Figure 1 A schematic diagram of the protruding structure of the target body shown;

[0021] Figure 3 for Figure 2 The sectional view shown at point AA.

[0022] In the figure: 10, target body; 11, annular protrusion structure; 12, connecting part; 20, back plate. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0024] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In the description of this utility model, it should be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" connected to another element, there are no intermediate elements.

[0026] Please see Figures 1-3 This is a preferred embodiment of the precious metal sputtering target of the present invention, which is used to be installed in a vacuum magnetron sputtering device to sputter jewelry materials. Specifically, the precious metal sputtering target includes a target body 10 and a back plate 20 disposed on the bottom surface of the target body 10. The target body 10 is provided with an annular protrusion structure 11 and a connecting portion 12 that are mirror-symmetrical to the sputtering etching morphology. The center of the annular protrusion structure 11 is the highest part, and the center of the annular protrusion structure 11 gradually transitions to the edge in a saddle shape. The connecting portion 12 is planar, and the back plate 20 is welded to the target body 10.

[0027] The aforementioned precious metal sputtering target forms an annular protrusion structure 11 on the target body 10 that is mirror-symmetrical to the sputtering etching morphology, so that the sputtering process is excited at the protrusion, thereby significantly reducing the initial overall thickness of the target and significantly improving the utilization rate of the target.

[0028] Understandably, the aforementioned precious metal sputtering target is designed with an annular protrusion structure 11 that is opposite to the sputtering etching morphology, based on the target holder specifications of the sputtering coating machine. In this embodiment, the thickness of the connecting portion 12 is controlled at 2-3 mm, and the highest part of the annular protrusion structure 11 is 5-10 mm higher than the connecting portion 12, so that the target material has sufficient strength and resistance to deformation.

[0029] In one embodiment, due to the thermal stress generated in the target material during sputtering, to prevent warping and deformation, the target body 10 is divided into a top target block, a bottom target block, and several intermediate target blocks. The thickness and width of the top, bottom, and intermediate target blocks are all the same, and the number of intermediate target blocks is 6 to 12. Simultaneously, this design reduces the initial input of precious metal materials by using an indirect cooling method for the target material. Optionally, the surface of the top target block has a first arc-shaped protrusion, the surface of the bottom target block has a second arc-shaped protrusion, and the surface of the intermediate target blocks has a straight protrusion, making the shape of the protrusions mirror-symmetrical to the morphology of the sputtered etching area. The top, bottom, and intermediate target blocks are seamlessly spliced ​​to form a continuous target surface. By using CNC milling to flatten the bottom surface of the target material and the bonding surfaces between the target segments, a continuous target surface can be formed through the seamless splicing of each target segment. During sputtering, a continuous band of glow can be generated, ensuring the uniformity and quality of the coated film. The bottom surface of the target body 10 is flat, and the side of the back plate 20 that connects to the target body 10 is also flat. The target body 10 and the back plate 20 are tightly fitted together, and the back plate 20 is made of copper. The surface of the copper back plate 20 is milled flat using CNC to ensure that the bottom surface of the target section is completely fitted to the surface of the copper back plate 20.

[0030] In other embodiments, an indium solder paste layer (not shown) is provided between the back plate 20 and the target body 10, that is, the target and the copper back plate 20 are soldered together using low-temperature indium solder paste, which effectively ensures the cooling effect of the target during sputtering and prevents deformation and warping.

[0031] This invention addresses the problems of existing precious metal sputtering target structures and utilization rates by improving the target surface morphology. Based on the formation law of the sputtering etching zone, a raised structure opposite to the etching zone is pre-formed on the target surface, while significantly reducing the thickness of the target base. The target is divided into a top section, a bottom section, and several intermediate sections, and is manufactured using processes such as vacuum continuous casting, precision forging, vacuum annealing, precision molding, and precision milling. The target sections are seamlessly spliced ​​and firmly welded to the back plate 20. Experiments show that using the sputtering planar target structure of this application, the initial amount of precious metal input can be significantly reduced while achieving the same service life, and the utilization rate of the target can be significantly improved.

[0032] The technical principle is as follows: During sputtering, argon gas is ionized by impact, and the argon ions, under bias voltage, bombard the target surface at high speed, forming etching. Because electrons are confined near the target surface, forming a ring-shaped etching zone of a certain width, the etching depth is highest at the center of the zone. The etching gradually decreases in depth towards both sides, thus forming a racetrack-shaped etching groove resembling a wide, shallow pit, while other parts of the target surface are rarely etched. Based on the principle of reverse engineering, a laser confocal microscope is used to scan the etched area of ​​the target to determine the evolution of target material consumption. Based on this evolutionary pattern, the target structure is designed with the opposite shape, so that the sputtering process targets the protruding parts, thereby significantly reducing the initial overall thickness of the target.

[0033] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0034] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A precious metal sputtering target, characterized in that, The target body includes a target body and a back plate disposed on the bottom surface of the target body. The target body has an annular protrusion structure and a connecting part that are mirror-symmetrical to the sputtered etching morphology. The center of the annular protrusion structure is the highest part, and the center of the annular protrusion structure gradually transitions to the edge in a saddle shape. The connecting part is planar, and the back plate is welded to the target body.

2. The noble metal sputtering target according to claim 1, characterized in that, The thickness of the connecting part is controlled at 2-3 mm, and the highest part of the annular protrusion structure is 5-10 mm higher than the connecting part.

3. The noble metal sputtering target according to claim 1, characterized in that, The target body is divided into a top target block, a bottom target block, and several middle target blocks, and the thickness and width of the top target block, the bottom target block, and the middle target blocks are all the same.

4. The noble metal sputtering target according to claim 3, characterized in that, The number of intermediate target blocks is 6 to 12.

5. The noble metal sputtering target according to claim 3, characterized in that, The top section of the target block has a first arc-shaped protrusion on its surface, the bottom section of the target block has a second arc-shaped protrusion on its surface, and the middle section of the target block has a straight protrusion on its surface.

6. The noble metal sputtering target according to claim 3, characterized in that, The top target block, bottom target block, and middle target block are seamlessly spliced ​​together to form a continuous target surface.

7. The noble metal sputtering target according to claim 1, characterized in that, The bottom surface of the target body is a plane, and the side of the back plate that is connected to the target body is a plane. The target body and the back plate are in close contact.

8. The noble metal sputtering target according to claim 7, characterized in that, The back plate is made of copper.

9. The noble metal sputtering target according to claim 7, characterized in that, An indium solder paste layer is provided between the back plate and the target body.

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