Bonding wire for electronic devices and method of making the same

Abstract

The present application relates to the technical field of microelectronic packaging, and particularly relates to a bonding wire for electronic devices and a preparation method thereof.The bonding wire is composed of Cu 2-4%, Al 2-4%, Pd 0.1-0.5%, In 0.7-1.5%, Zn 0.2-0.5%, Ru 0.01-0.06%, and the balance of Ag, in terms of mass percentage.The present application discards the traditional method of adding rare earth elements to improve the corrosion resistance of silver-based bonding wires, and significantly improves the corrosion resistance of silver-based bonding wires by optimizing the alloy component design, especially the addition of In, Zn, Ru and other components, while taking into account good mechanical properties and process adaptability.The silver-based bonding wire provided by the present application can be used as an ideal substitute material for gold wire, and can be applied to the fields of microelectronic packaging such as integrated circuits, LED packaging, power devices, MEMS packaging, etc.

Description

Technical Field

[0001] This invention relates to the field of microelectronic packaging technology, specifically to a bonding wire for electronic devices and its preparation method. Background Technology

[0002] Wire bonding, as the mainstream interconnect technology in microelectronic packaging, has advantages such as mature process, low cost, and strong adaptability, and is widely used in integrated circuits, LED packaging, and power devices. With the rapid development of emerging technologies such as 5G communication, artificial intelligence, and the Internet of Things, the microelectronics industry has placed higher demands on packaging technology. Packaging technology is developing towards high density, miniaturization, and high reliability, which places higher demands on the performance of bonding wires.

[0003] Gold bonding wires have long dominated the mid-to-high-end packaging market due to their excellent chemical stability, good bonding performance, and long-term reliability. However, as a precious metal, gold's price remains high, resulting in gold wires accounting for a significant portion of the total packaging cost. To reduce packaging costs, the industry has successively developed copper and silver bonding wires as alternatives to gold wires.

[0004] While copper bonding wires are less expensive, their high rigidity can easily damage the chip during bonding, and they are prone to oxidation and corrosion in non-hermetic packaging, affecting the long-term reliability of the device. Silver bonding wires, with their excellent electrothermal properties, good reflectivity, and moderate cost advantage, are gradually becoming a highly promising alternative to gold wires. Furthermore, silver has good solderability with silver-plated substrates, further enhancing the competitiveness of silver wires in the packaging field.

[0005] However, pure silver wire has significant performance shortcomings in practical applications, severely restricting its widespread use in high-end packaging. Silver is extremely sensitive to sulfides, readily undergoing sulfidation reactions in sulfur-containing environments to form black Ag₂S, leading to a sharp increase in contact resistance and even bond failure. In the actual operating environment of electronic packaging, trace amounts of sulfur-containing gases such as H₂S and SO₂ in the atmosphere, as well as sulfur-containing substances that may be released from the packaging materials, can all become sources of silver corrosion. Furthermore, pure silver wire also suffers from low strength, susceptibility to silver ion migration, and difficulty in controlling the growth of intermetallic compounds. These problems are particularly pronounced under conditions involving high temperature and humidity, strong electric fields, and other coupled factors.

[0006] To overcome the aforementioned shortcomings of pure silver wire, researchers have attempted to modify the silver matrix by adding trace alloying elements. In recent years, research on the microalloying of silver-based bonding wires has made a series of advances. For example, existing techniques have shown that adding rare earth elements such as cerium and lanthanum can improve the corrosion resistance of silver alloy wires. However, the addition of rare earth elements significantly increases material costs and causes environmental pollution problems. Furthermore, the addition of rare earth elements reduces the tensile strength and elongation of silver alloys, which is detrimental to improving product performance.

[0007] Therefore, developing a silver-based bonding wire that has excellent corrosion resistance while maintaining good mechanical properties and processability has significant theoretical research value and industrial application prospects. Summary of the Invention

[0008] The purpose of this invention is to provide a bonding wire for electronic devices and its preparation method. It abandons the traditional method of improving the corrosion resistance of silver-based bonding wires by adding rare earth elements. By optimizing the alloy composition design, especially by adding elements such as In, Zn, and Ru, the corrosion resistance of silver-based bonding wires is significantly improved, while taking into account good mechanical properties and process adaptability.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A bonding wire for electronic devices has the following composition by mass percentage: Cu 2-4%, Al 2-4%, Pd 0.1-0.5%, In 0.7-1.5%, Zn 0.2-0.5%, Ru 0.01-0.06%, with the balance being Ag.

[0010] Cu, Al, and Pd are the main additive elements, providing fundamental mechanical properties; In, Zn, and Ru impart excellent corrosion resistance to the silver-based bonding wire. Cu and Ag are miscible in the solid state, forming a solid solution. The atomic size of Cu differs from that of Ag; when Cu atoms enter the Ag lattice, they cause lattice distortion, hindering dislocation movement and resulting in solid solution strengthening. Simultaneously, the addition of Cu refines the grain size, and the increased grain boundary area enhances the dislocation pile-up effect, further improving strength through grain refinement. Al and Ag also form a solid solution, contributing to solid solution strengthening. Furthermore, the presence of Al facilitates the formation of a thin, dense oxide layer when the alloy comes into contact with corrosive solutions, providing initial passivation protection to the silver matrix. However, the Al content should not be too high, otherwise it will reduce processing performance. Pd, as a key auxiliary element, has a high melting point and strong chemical inertness. In the silver matrix, Pd can improve the high-temperature stability of the silver alloy, refine the grain structure, and improve bonding performance.

[0011] In is a key element for improving the performance of silver-based bonded wires. During corrosion, it readily forms a dense oxide protective film on the silver substrate surface, effectively blocking the diffusion and penetration of corrosive media into the silver substrate. Simultaneously, In inhibits grain growth. The refined grain structure reduces the defect density within individual grains, lowering the preferential pathway for corrosion along grain boundaries. Zn complements In, protecting the silver substrate and effectively slowing down the Ag corrosion process. Furthermore, the zinc oxide formed during corrosion fills the micropores in the oxide film, further enhancing its density. The composite oxide film formed by Zn and In provides superior protection compared to a single oxide film. Ru, with its extremely high chemical inertness, forms a physical barrier, effectively blocking the migration paths of corrosive ions. Moreover, the presence of Ru enhances the surface enrichment effect to some extent, resulting in a more rapid and denser formation of the surface protective film.

[0012] In one embodiment, a bonding wire for an electronic device comprises, by mass percentage: Cu 2.2-3.8%, Al 2.2-3.8%, Pd 0.2-0.5%, In 0.8-1.4%, Zn 0.25-0.45%, Ru 0.02-0.06%, with the balance being Ag.

[0013] In one embodiment, a bonding wire for an electronic device comprises, by mass percentage: Cu 2.5-3.5%, Al 2.5-3.5%, Pd 0.2-0.4%, In 0.9-1.3%, Zn 0.3-0.4%, Ru 0.03-0.05%, with the balance being Ag.

[0014] In one embodiment, a bonding wire for an electronic device comprises, by mass percentage: Cu 2.5-3.5%, Al 2-3%, Pd 0.25-0.35%, In 1.0-1.2%, Zn 0.3-0.4%, Ru 0.03-0.04%, with the balance being Ag.

[0015] In one embodiment, a bonding wire for an electronic device comprises, by mass percentage: Cu 3%, Al 3%, Pd 0.3%, In 1.2%, Zn 0.4%, Ru 0.06%, with the balance being Ag.

[0016] Overall, during the corrosion process, In is responsible for forming a primary oxide protective film on the silver substrate surface. The addition of Zn can improve the density and stability of the protective film and eliminate continuous corrosion channels. Ru, on the other hand, can accelerate the formation rate of the protective film by enhancing the surface enrichment effect. Meanwhile, the content of each component should be carefully adjusted during the preparation of the bonding wire. For example, Pd can refine the grain structure and improve bonding performance; however, an increase in Pd content will make the wire more prone to breakage during drawing. When the In content is too low, the surface protective film is discontinuous and cannot form a complete coverage; when it is too high, excessive In becomes a preferential initiation point for corrosion. A suitable amount of Zn can provide protection, but excessive Zn addition reduces the elongation and processing performance of the alloy. As an inert element, Ru has little modification effect when its content is too low; when its content is too high, it will impair the drawing performance of the wire.

[0017] On the other hand, the present invention also provides a method for preparing bonding wires for electronic devices, which mainly includes the following steps: melting and casting raw materials according to the proportion; and then preparing bonding wires for electronic devices by sequentially performing wire drawing, intermediate annealing, re-wire drawing, and re-annealing processes.

[0018] In one embodiment, the melting is carried out under vacuum protection at a temperature of 1200-1500°C; further, the melting temperature is 1250-1450°C. In particular, the melting can be repeated multiple times to ensure that all alloying elements are fully melted and uniformly distributed. Specifically, intermediate alloy raw materials can be used for melting.

[0019] In one embodiment, alloy wire is formed by casting at a speed of 10-40 mm / s, and the diameter of the alloy wire formed by casting is 5-15 mm.

[0020] In one embodiment, alloy wire with a diameter of 0.5-2 mm is obtained by drawing, and the drawing speed is 5-20 mm / s.

[0021] In one embodiment, intermediate annealing is performed under inert gas conditions, which may be argon or nitrogen. Specifically, the intermediate annealing temperature is 300-500°C, and the intermediate annealing rate is 50-100 m / min. Annealing eliminates internal stress, restores plasticity, and eliminates work hardening.

[0022] In one embodiment, 10-60µm alloy wire is formed by redrawing at a drawing speed of 5-20mm / s. A suitable drawing speed ensures optimized drawing stability and dimensional accuracy.

[0023] In one embodiment, the re-annealing can be carried out under inert gas conditions, with an annealing temperature of 300-500°C and an annealing speed of 50-100 m / min. Specifically, the annealing can be carried out in an annealing furnace, with an effective furnace length of 600-800 mm.

[0024] Beneficial Effects: This invention provides a bonding wire for electronic devices that abandons the traditional method of improving the corrosion resistance of silver-based bonding wires by adding rare earth elements, thus preventing the problem of reduced mechanical properties caused by rare earth addition. By optimizing the alloy composition design, especially through the addition of various elements, the corrosion resistance of silver-based bonding wires is significantly improved, while maintaining good mechanical properties and process adaptability. Cu, Al, and Pd are the main additive elements, providing basic mechanical property support; In, Zn, and Ru endow the silver-based bonding wires with excellent corrosion resistance. The addition of Cu refines the grains, and the increased grain boundary area enhances the dislocation pile-up effect, further improving strength through grain refinement strengthening. Al, like Ag, forms a solid solution, providing solid solution strengthening. Pd enhances its high-temperature stability, refines the grain structure, and improves bonding performance. In is responsible for forming a primary protective film on the surface of the silver substrate, while the addition of Zn can improve the density and stability of the protective film and eliminate continuous corrosion channels; Ru, on the other hand, can accelerate the formation of the protective film by enhancing the surface enrichment effect, and significantly improve the overall corrosion resistance. Detailed Implementation

[0025] The following embodiments are provided to better understand the present invention and do not constitute a limitation on the content and scope of protection of the present invention. The present invention is not limited to the described preferred embodiments. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0026] Performance testing: The breaking strength of the bonding wires for electronic devices prepared in Examples 1-8 and Comparative Examples 1-4 was tested, and the corrosion rate of the bonding wires for electronic devices when immersed in a 0.1 mol / L sodium sulfide aqueous solution at room temperature for 200 h was also tested.

[0027] Example 1 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 4%, Al 4%, Pd 0.1%, In 1.5%, Zn 0.5%, Ru 0.01%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1300℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 60m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 440℃ and an annealing speed of 60m / min. Its tensile strength is 13.4 gf; its corrosion rate is 0.030 mg·cm⁻¹. -2 .

[0028] Example 2 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 2%, Al 2%, Pd 0.4%, In 0.7%, Zn 0.2%, Ru 0.05%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 500℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min. Its tensile strength is 12.3 gf; its corrosion rate is 0.032 mg·cm⁻¹. -2 .

[0029] Example 3 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.5%, In 1.2%, Zn 0.4%, Ru 0.04%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 12.6 gf; its corrosion rate is 0.029 mg·cm⁻¹. -2 .

[0030] Example 4 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 2.5%, Al 2.5%, Pd 0.2%, In 0.9%, Zn 0.3%, Ru 0.02%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1300℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 490℃ and an annealing speed of 60m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 12.5 gf; its corrosion rate is 0.035 mg·cm⁻¹. -2 .

[0031] Example 5 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 1.2%, Zn 0.4%, Ru 0.04%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 13.2 gf; its corrosion rate is 0.026 mg·cm⁻¹. -2 .

[0032] Example 6 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3.5%, Al 3.5%, Pd 0.4%, In 1.3%, Zn 0.3%, Ru 0.03%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 470℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 450℃ and an annealing speed of 70m / min. Its tensile strength is 13.0 gf; its corrosion rate is 0.027 mg·cm⁻¹. -2 .

[0033] Example 7 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 2.8%, Al 3.2%, Pd 0.3%, In 1.0%, Zn 0.4%, Ru 0.02%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 500℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 12.4 gf; its corrosion rate is 0.031 mg·cm⁻¹. -2 .

[0034] Example 8 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 1.2%, Zn 0.4%, Ru 0.06%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 12.7 gf; its corrosion rate is 0.028 mg·cm⁻¹. -2 .

[0035] Comparative Example 1 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 0%, Zn 1.44%, Ru 0.22%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its breaking strength is 12.1gf; its corrosion rate is 0.072mg·cm. -2 .

[0036] Comparative Example 2 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 1.58%, Zn 0%, Ru 0.08%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its breaking strength is 12.5gf; its corrosion rate is 0.065mg·cm. -2 .

[0037] Comparative Example 3 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 1.25%, Zn 0.41%, Ru 0%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its breaking strength is 12.3gf; its corrosion rate is 0.050mg·cm. -2 .

[0038] Comparative Example 4 A bonding wire for electronic devices, the composition of which, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 0.4%, Zn 1.2%, Ru 0.06%, with the balance being Ag. The preparation method of the bonding wire for electronic devices includes the following steps: (1) melting under vacuum protection at a melting temperature of 1350℃; casting (speed 30mm / s) to form an alloy wire with a diameter of 10mm; (2) drawing (speed 15mm / s) to obtain an alloy wire with a diameter of 1mm; (3) annealing under argon conditions at a annealing temperature of 480℃ and an annealing speed of 70m / min; (4) drawing again (speed 15mm / s) to form a 30µm alloy wire; (5) annealing under argon conditions at a annealing temperature of 460℃ and an annealing speed of 70m / min. Its tensile strength is 11.9 gf; its corrosion rate is 0.055 mg·cm⁻¹. -2 .

[0039] As can be seen from the above embodiments and comparative examples, the present invention provides a bonding wire for electronic devices, wherein Cu, Al, and Pd are the main additive elements, providing basic mechanical property support; In, Zn, and Ru endow the silver-based bonding wire with excellent sulfur corrosion resistance. The addition of Cu can refine the grains, and the increase in grain boundary area enhances the dislocation pile-up effect, further improving the strength through grain refinement strengthening. Al and Ag also form a solid solution, which can play a solid solution strengthening effect. Pd can enhance its high-temperature stability, refine the grain structure, and improve bonding performance. In, Zn, and Ru endow the silver-based bonding wire with excellent sulfur corrosion resistance. Specifically, compared with Example 8, when Comparative Examples 1-3 lack any one of the In, Zn, or Ru components, the reduction in tensile strength is not significant, but the corrosion resistance is greatly reduced. This indicates that in the system of this invention, In is responsible for forming a primary protective film on the silver substrate surface. The addition of Zn can improve the density and stability of the protective film and eliminate continuous corrosion channels. Ru, by enhancing the surface enrichment effect, can accelerate the formation rate of the protective film and significantly improve the overall corrosion resistance. However, in Comparative Example 4, the amounts of In and Zn were interchanged, i.e., too little In and too much Zn, resulting in a significant decrease in both mechanical properties and corrosion resistance. This shows that the content of each component should be carefully adjusted during the preparation of the bonding wire. When the In content is too low, the surface protective film is discontinuous and cannot form a complete coverage; when it is too high, it becomes a preferential initiation point for corrosion. An appropriate amount of Zn can provide protection, but too much will also lead to a decrease in product performance.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bonding wire for electronic devices, characterized in that, The composition, by mass percentage, is as follows: Cu 2-4%, Al 2-4%, Pd 0.1-0.5%, In 0.8-1.4%, Zn 0.25-0.5%, Ru 0.01-0.06%, with the balance being Ag; The method for preparing a bonding wire for electronic devices includes the following steps: melting and casting raw materials according to a ratio; then preparing the bonding wire for electronic devices by sequentially performing wire drawing, intermediate annealing, re-wire drawing, and re-annealing processes; the intermediate annealing is carried out under inert gas conditions.

2. The bonding wire for electronic devices as described in claim 1, characterized in that, The composition, by mass percentage, is as follows: Cu 2.2-3.8%, Al 2.2-3.8%, Pd 0.2-0.5%, In 0.8-1.4%, Zn 0.25-0.45%, Ru 0.02-0.06%, with the balance being Ag.

3. The bonding wire for electronic devices as described in claim 1, characterized in that, The composition, by mass percentage, is as follows: Cu 2.5-3.5%, Al 2.5-3.5%, Pd 0.2-0.4%, In 0.9-1.3%, Zn 0.3-0.4%, Ru 0.03-0.05%, with the balance being Ag.

4. The bonding wire for electronic devices as described in claim 1, characterized in that, The composition, by mass percentage, is as follows: Cu 2.5-3.5%, Al 2-3%, Pd 0.25-0.35%, In 1.0-1.2%, Zn 0.3-0.4%, Ru 0.03-0.04%, with the balance being Ag.

5. The bonding wire for electronic devices as described in claim 1, characterized in that, The composition, by mass percentage, is: Cu 3%, Al 3%, Pd 0.3%, In 1.2%, Zn 0.4%, Ru 0.06%, with the balance being Ag.

6. A method for preparing a bonding wire for electronic devices as described in any one of claims 1-5, characterized in that, Includes the following steps: According to the formula, the raw materials are melted and cast; then the bonding wire for electronic devices is prepared by sequentially drawing, intermediate annealing, drawing again, and annealing; the intermediate annealing is carried out under inert gas conditions.

7. The method for preparing a bonding wire for electronic devices as described in claim 6, characterized in that, The melting temperature is 1200-1500℃.

8. The method for preparing a bonding wire for electronic devices as described in claim 6, characterized in that, The melting temperature is 1250-1450℃.

9. The method for preparing a bonding wire for electronic devices as described in claim 6, characterized in that, The intermediate annealing temperature is 300-500℃.

10. The method for preparing a bonding wire for electronic devices as described in claim 6, characterized in that, The intermediate annealing rate is 50-100 m / min.