JP7774698B2 - Silver alloy bonding wire, its preparation method and use - Google Patents

Description

The present invention belongs to the technical field of packaging materials, and in particular relates to silver alloy bonding wire, its preparation method and use.

Wire bonding is the most common and most important interconnection method for microelectronic packages. Bonding wire is the inner lead for packaging, and is used as a welding lead between the chip and the frame to connect with pins and silicon wafers and transmit electrical signals, serving as an electrical connection between the chip and external circuits. It is one of the basic raw materials essential for the repackaging manufacturing process of integrated circuits, semiconductor discrete devices, and LED light source devices. Bonding wire mainly includes gold wire, silver wire, aluminum wire, copper wire, etc. Silver wire has good mechanical properties, can reduce high-frequency noise and heat generation in devices, and has a significant price advantage over gold wire.

As semiconductor packaging becomes increasingly dense and integrated, bonding reliability is becoming more important. However, silver wires have problems such as low bond strength, electromigration, and metal corrosion and sulfidation, which reduce reliability and significantly limit their applications.
In view of this, the present invention has been devised.

The primary objective of the present invention is to provide a silver alloy bonding wire with excellent mechanical properties and corrosion resistance.

A second object of the present invention is to provide a method for preparing silver alloy bonding wire that can improve the mechanical properties and corrosion resistance of the bonding wire.

A third object of the present invention is to provide a silver alloy bonding wire for use in electronic packaging, which can improve bonding reliability.

To achieve the above objectives of the present invention, the following technical solutions are particularly adopted.

The present invention provides a silver alloy bonding wire. The silver alloy bonding wire includes a core material containing, by mass fraction, 0.5 wt% to 0.7 wt% Al, 0.6 wt% to 1 wt% Ce, 1 wt% to 3 wt% carbon nanotubes, 0.3 wt% to 0.5 wt% Sb, and the remainder being Ag.

Furthermore, in the core material, the total mass fraction of the Al and the Sb is 1%, and/or the total mass fraction of the Al, the Ce, the carbon nanotubes, and the Sb in the core material is 3.5% or less.

Furthermore, the carbon nanotubes include single-walled carbon nanotubes, and/or the carbon nanotubes have a diameter of 2 nm or less and a length of 50 nm or less.

Furthermore, the core material further includes a protective layer formed on the surface thereof, and/or the protective layer formed on the surface of the core material includes, by weight, 3 to 5 parts of a film-forming agent, 1 to 3 parts of a surfactant, and 1 to 3 parts of a solubilizing agent.

Furthermore, the film-forming agent includes at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate, the surfactant includes at least one of polyethylene glycol fatty acid ester, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate, and the solubilizing agent includes at least one of para-aminobenzoic acid, acetone, and methanol.

Furthermore, the diameter of the core material is 15 to 40 μm, and/or the thickness of the protective layer is 1.5 to 4 μm.

The present invention further provides a method for preparing the above-mentioned silver alloy bonding wire. The preparation method includes step S1 of melting and pouring the Ag/Ce intermediate alloy, the Sb raw material, the Al foil, and the carbon nanotubes in that order to obtain a rod, and step S2 of extruding and drawing the rod in that order to obtain the core material.

Furthermore, in step S2, the extrusion temperature is 700 to 750°C, and/or the extrusion ratio is 3 to 4.5.

Furthermore, the method for preparing the silver alloy bonding wire includes at least one of the following: (1) the core material is subjected to cleaning, annealing, and immersion treatments in order to obtain the silver alloy bonding wire; (2) the annealing temperature is 450 to 500°C; and (3) the immersion treatment includes immersing the annealed core material in a protective agent to obtain a protective layer, the protective agent containing, by weight, 3 to 5 parts of film-forming agent, 1 to 3 parts of surfactant, 1 to 3 parts of dissolution aid, and 70 to 80 parts of solvent.

The present invention further provides the use of the above-described silver alloy bonding wire or a silver alloy bonding wire prepared by the above-described method for preparing a silver alloy bonding wire in electronic packaging.

Compared with the prior art, the present invention has the following beneficial effects:
1. The silver alloy bonding wire of the present invention is obtained by adding Sb and carbon nanotubes to the silver alloy, and by cooperating with Ce and Al, the mechanical properties, processing performance, electromigration resistance, and corrosion resistance of the silver alloy bonding wire are improved, and the requirements for fine wire diameter processing and high-density lead packaging for LED devices can be met.
2. The silver alloy bonding wire according to the present invention has a protective layer on the surface of the core material, which further improves the corrosion resistance of the silver alloy bonding wire and prevents sulfurization and corrosion of the core material.
3. The method for preparing the silver alloy bonding wire according to the present invention can increase the density and strength of the silver alloy bonding wire through processes such as melting, pouring, and extrusion.

In order to more clearly describe the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the specific embodiments or the prior art will be briefly described below. The drawings described only show some embodiments of the present invention. Those skilled in the art can obtain other drawings based on these drawings without using inventive ability.
1 is a graph showing the corrosion resistance of silver alloy bonding wires 1# to 11# according to Example 1 of the present invention and Comparative Example 1.

The following provides a clear and complete explanation of the technical solutions of the present invention with the aid of drawings and specific embodiments. Those skilled in the art will understand that the described examples are only some of the examples of the present invention, not all of the examples, and are intended to illustrate the present invention and not to limit the scope of the present invention. All other examples that are obtained by those skilled in the art based on the examples of the present invention without using their inventive abilities also fall within the scope of protection of the present invention. In the examples, where specific conditions are not specified, they can be carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or equipment whose manufacturers are not specified, conventional commercially available products can be used.

Note that the term "and/or" used in this specification represents a relationship between related objects, and indicates that a three-way relationship exists. For example, A and/or B represents a three-way relationship in which only A exists, both A and B exist, and only B exists.

Some embodiments of the present invention provide a silver alloy bonding wire. The silver alloy bonding wire includes a core material containing, by mass fraction, 0.5 wt% to 0.7 wt% Al, 0.6 wt% to 1 wt% Ce, 1 wt% to 3 wt% carbon nanotubes, 0.3 wt% to 0.5 wt% Sb, and the remainder being Ag.

The silver alloy bonding wire of the present invention solves the problems associated with silver wire, such as low connection strength, susceptibility to electromigration, and metal corrosion and sulfurization. The silver alloy bonding wire of the present invention has excellent mechanical properties, processability, electromigration resistance, sulfurization resistance, and corrosion resistance, and can meet the packaging requirements of LED devices with fine wire diameter processing and high-density leads.

In the silver alloy bonding wire of the present invention, the addition of Al element forms a dense protective layer on the silver surface, passivating the surface and improving the corrosion resistance of the silver alloy wire. The addition of Ce element improves corrosion resistance and increases the growth and diffusion rate of IMC at the Ag/Al interface, improving bonding reliability. The addition of carbon nanotubes increases thermal conductivity and reduces electron mobility. Carbon nanotubes, as a nano-reinforcement phase, promote the non-spontaneous nucleation of silver metal liquid by increasing the number of nucleation sites, thereby refining the crystal grains and increasing the strength of the bonding wire. The addition of Sb element causes the Sb element to accumulate at the crystal grain boundaries, thereby reducing diffusion along the crystal grain boundaries and improving strength and electromigration resistance.

In some embodiments of the present invention, as a representative and non-limiting example, in the core material, the mass fraction of Al is 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, or a value within a range consisting of any two values therein, and the mass fraction of Ce is 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, 1 wt%, or any two values therein. The mass fraction of carbon nanotubes is 1 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.2 wt%, 2.4 wt%, 2.6 wt%, 2.8 wt%, 3 wt%, or a value within a range consisting of any two values thereof, and the mass fraction of Sb is 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, or a value within a range consisting of any two values thereof.

The present invention further optimizes the composition of the core material in silver alloy bonding wire to improve the mechanical properties and corrosion resistance of the silver alloy bonding wire.

In some embodiments of the present invention, the core material contains, by mass fraction, 0.55 wt% to 0.65 wt% Al, 0.75 wt% to 0.85 wt% Ce, 1.1 wt% to 1.3 wt% carbon nanotubes, 0.3 wt% to 0.5 wt% Sb, and the remainder Ag.

In some embodiments of the present invention, the total mass fraction of Al and Sb in the core material is 1%.

In some embodiments of the present invention, the total mass fraction of Al, Ce, carbon nanotubes, and Sb in the core material is 3.5% or less.

In some embodiments of the present invention, the carbon nanotubes include single-walled carbon nanotubes.

In some embodiments of the present invention, the carbon nanotubes have a diameter of 2 nm or less and a length of 50 nm or less.

By using carbon nanotubes of the above sizes, the carbon nanotubes can be distributed uniformly throughout the alloy. When the bonding wire is drawn to an extremely thin state, the carbon nanotubes are relatively large, which is unfavorable for deformation and drawing of the alloy and results in poor mechanical properties.

In some embodiments of the present invention, the bonding wire further includes a protective layer provided on the surface of the core material.

In some embodiments of the present invention, the protective layer comprises, by weight, 3 to 5 parts of a film-forming agent, 1 to 3 parts of a surfactant, and 1 to 3 parts of a solubilizing agent.

In some embodiments of the present invention, the film-forming agent includes, but is not limited to, at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate.

In some embodiments of the present invention, the surfactant includes, but is not limited to, at least one of polyethylene glycol fatty acid esters, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate.

In some embodiments of the present invention, the solubilizing agent includes, but is not limited to, at least one of para-aminobenzoic acid, acetone, and methanol. Para-aminobenzoic acid can remove dirt, oil, etc., and can also act as an anti-corrosion agent.

The protective layer of the present invention can prevent sulfidation and corrosion of the core material of the silver alloy bonding wire and does not affect the bonding process of the silver alloy bonding wire.

In some embodiments of the present invention, the protective layer comprises, by weight, 3 to 5 parts ethylene glycol monovinyl ether, 1 to 3 parts polyethylene glycol fatty acid ester, and 1 to 3 parts para-aminobenzoic acid.

In some embodiments of the present invention, the diameter of the core material is 15 to 40 μm, typically and non-limitingly, for example, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or a value within a range consisting of any two values therein, and the thickness of the protective layer is 1.5 to 4 μm, typically and non-limitingly, for example, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, or a value within a range consisting of any two values therein.

In some embodiments of the present invention, the tensile break strength of the silver alloy bonding wire is 9 to 10 g.

In some embodiments of the present invention, the elongation of the silver alloy bonding wire is between 9% and 12%, preferably between 10.5% and 12%.

Some embodiments of the present invention further provide a method for preparing the above-mentioned silver alloy bonding wire. The preparation method includes the following steps:

Step S1: The Ag/Ce intermediate alloy, Sb raw material, Al foil, and carbon nanotubes are melted and poured in order to obtain a rod.

Step S2: The rod material is extruded and drawn in sequence to obtain the core material.

The method for preparing silver alloy bonding wire according to the present invention can increase the density and strength of the silver alloy bonding wire through processes such as melting, pouring, and extrusion.

In some embodiments of the present invention, the method for preparing an Ag/Ce intermediate alloy in step S1 includes the following:

The Ag raw material and the Ce raw material are weighed according to the blending ratio and placed in a crucible in a vacuum furnace. The furnace door is closed, the furnace is evacuated to 3×10 ⁻² Pa, argon gas is introduced until the pressure reaches 0.1 to 0.3 Pa, and the temperature is raised to 600 to 800°C. The evacuation and argon gas introduction operations are repeated three times, and the temperature is raised to 1200 to 1250°C. The mixture is stirred for 3 to 5 minutes, refined for 10 to 15 minutes, degassed, and cooled in the furnace to obtain an Ag/Ce intermediate alloy. Preferably, the purity of each of the Ag raw material and the Ce raw material is greater than 99.99%.

In some embodiments of the present invention, in step S1, an Ag/Ce intermediate alloy, an Sb raw material, an Al foil, and carbon nanotubes are placed in a vacuum furnace, which is then evacuated to 2×10 ⁻² Pa, and argon gas is introduced to 0.1 to 0.3 Pa. The evacuation and argon gas introduction operations are repeated three times, and the temperature is increased to 1250 to 1300°C, and the mixture is stirred using a magnetic stirrer for 15 to 20 minutes. When the temperature is reduced to 1150 to 1200°C, a rod having a diameter of 30 to 50 mm is formed by pouring the molten metal.

In some embodiments of the present invention, the method for adding the Al foil and carbon nanotubes in step S1 involves laying the carbon nanotube powder on the Al foil, sandwiching it between two sheets of Al foil, and folding it over to add it.

In some embodiments of the present invention, the extrusion temperature in step S2 is 700-750°C, and the extrusion ratio is 3-4.5. Preferably, the extrusion includes the following: placing the rod in an extruder container, heating it to 700-750°C, and holding it at that temperature for 2 hours; extruding the rod at a speed of 3-4 mm/s, an extrusion ratio of 3-4.5, and a rotation speed of the extrusion wheel of 5-7 r/min; and extruding a rod having a diameter of 5-10 mm.

This invention utilizes degassing, refining, and rod pouring, and uses peeling extrusion for the rods instead of continuous casting, further increasing density and strength.

In some embodiments of the present invention, the drawing includes at least two drawing processes, with a heat treatment being performed after each drawing process before the next drawing process. Preferably, the drawing includes a first drawing process, a heat treatment, and a second drawing process, in sequence.

In some embodiments of the present invention, the first wire drawing process in step S2 involves drawing the extruded rod into a wire having a diameter of 0.8 to 1.1 mm using a wire drawing machine, with a reduction rate per extrusion pass of 15% to 18% and a wire drawing speed of 1.2 to 1.8 m/s.

In some embodiments of the present invention, the heat treatment in step S2 includes the following: placing a wire rod having a diameter of 0.8 to 1.1 mm in a vacuum annealing furnace, heating it to 350 to 400°C at a rate of 2 to 3.5°C/s under a vacuum of 3 x ^10-2 to 5 x ^10-2 Pa, and heat-treating it for 3 to 5 hours, followed by furnace cooling to 80°C or less.

In some embodiments of the present invention, the second wiredrawing process in step S2 includes the following: The heat-treated wire is subjected to drawing using a multi-wiredrawing machine, and a core material with a wire diameter of 15 to 40 μm is obtained by drawing a thin wire. Preferably, during the drawing process using the multi-wiredrawing machine, the reduction rate per pass is 10% to 13%, and the drawing speed is 2 to 2.5 m/s. During the drawing process of the thin wire, the diameter reduction rate is 15% to 18%, and the drawing speed is 3 to 5 m/s.

In some embodiments of the present invention, the method for preparing a silver alloy bonding wire further includes the steps of sequentially cleaning, annealing, and immersing the core material to obtain a silver alloy bonding wire.

In some embodiments of the present invention, annealing includes passing the cleaned core material through an in-line annealing device equipped with an antioxidant liquid dripping device, at a passing speed of 2.5 to 3 m/s, and at an annealing temperature of 450 to 500°C.

Annealing can remove the work hardening from the previous process, improve the stability and reliability of the bonding wire, and improve the mechanical strength of the bonding wire, allowing it to withstand greater tensile breaking force. The resistivity and conductivity of the bonding wire are deeply dependent on its crystal structure and lattice defects, and annealing can promote grain growth and the repair of lattice defects, thereby improving the electrical performance and conductivity of the bonding wire.

In some embodiments of the present invention, the immersion treatment includes immersing the annealed core material in a protective agent to obtain a protective layer.

The protective agent contains, by weight, 3-5 parts of film-forming agent, 1-3 parts of surfactant, 1-3 parts of solubilizing agent, and 70-80 parts of solvent.

In some embodiments of the present invention, the solvent includes, but is not limited to, ethanol.

In some embodiments of the present invention, the immersion treatment is performed for a period of 20 to 25 minutes at a temperature of 40 to 50°C.

In some embodiments of the present invention, cleaning involves immersing the core material in deionized water and applying ultrasonic vibrations for 5 to 10 minutes to remove surface dirt.

In some embodiments of the present invention, the immersion process further includes the steps of rinsing with deionized water, subjecting the substrate to ultrasonic vibration for 15 to 20 minutes, drying with nitrogen gas, and winding the substrate onto a reel.

Some embodiments of the present invention further provide for the use of the above-described silver alloy bonding wire or a silver alloy bonding wire prepared by the above-described method for preparing a silver alloy bonding wire in electronic packaging.

Example 1
This example provides a method for preparing a silver alloy bonding wire. The core material components and contents (mass fractions) of the prepared silver alloy bonding wire are shown in Table 1.

Specifically, the method for preparing the above-mentioned silver alloy bonding wire includes the following steps:

Step S1: An Ag raw material having a purity of more than 99.99% and a Ce raw material having a purity of more than 99.9% are placed in the crucible of a vacuum melting furnace, the furnace door is closed, the furnace is evacuated to 2×10 ⁻² Pa, argon gas is introduced to 0.1 to 0.3 Pa, the evacuation operation and argon gas introduction operation are repeated three times, the furnace body is heated to 1200 to 1250°C, stirred for 3 to 5 minutes, kept at that temperature and refined for 10 to 15 minutes, degassed, and the furnace is cooled to room temperature to obtain an Ag/Ce intermediate alloy.

Step S2: An Ag/Ce intermediate alloy, an Sb raw material with a purity of 99.99%, and carbon nanotubes (single-walled carbon nanotubes, diameter ≦2 nm, length ≦50 nm) coated with Al foil (the purity of the Al foil was 99.99%, and the carbon nanotube powder was laid on the Al foil, sandwiched between two sheets of Al foil, and folded for addition) were mixed according to the compounding ratio, placed in a vacuum melting furnace, evacuated to 2×10 ⁻² Pa, and then argon gas was introduced to 0.1 to 0.3 Pa. The evacuation operation and argon gas introduction operation were repeated three times, and the temperature was raised to 1250 to 1300°C and stirred using a magnetic stirrer for 15 to 20 minutes. When the temperature was lowered to 1150 to 1200°C, a rod with a diameter of 30 to 50 mm was formed by pouring the molten metal.

Step S3: A rod with a diameter of 30-50 mm was placed in the extruder container, heated to 700-750°C, and kept at that temperature for 2 hours. After extrusion, the head and tail were separated to obtain a rod with a diameter of 5-10 mm. The extrusion speed of the rod was 3-4 mm/s, the extrusion ratio was 3-4.5, and the rotation speed of the extrusion wheel was 5-7 r/min.

Step S4: The rod material with a diameter of 5 to 10 mm was drawn into wire material with a diameter of 0.8 to 1.1 mm using a wire drawing machine, with a reduction rate per pass of 15% to 18% and a wire drawing speed of 1.2 to 1.8 m/s.

Step S5: A wire having a diameter of 0.8 to 1.1 mm was placed in a vacuum annealing furnace, heated to 350 to 400°C at a rate of 2 to 3.5°C/s under a vacuum of 3 x ^10-2 to 5 x ^10-2 Pa, and heat-treated for 3 to 5 hours. Then, the wire was cooled to 80°C or below and removed from the furnace.

Step S6: The heat-treated wire was drawn using a multi-wire drawing machine to produce a wire with a diameter of 0.1 mm or less. The reduction rate per pass was 10% to 13%, and the drawing speed was 2 to 2.5 m/s.

Step S7: A wire with a diameter of 0.1 mm or less was subjected to fine wire drawing to obtain a core material with a diameter of 15 μm. The diameter reduction rate was 15% to 18%, and the wire drawing speed was 3 to 5 m/s.

Step S8: The core material was immersed in deionized water and subjected to ultrasonic vibrations for 5 to 10 minutes to remove surface dirt.

Step S9: The cleaned core material was passed through an in-line annealing device equipped with an antioxidant liquid dripping device, with a linear velocity of 2.5-3 m/s and an annealing temperature of 450-500°C.

Step S10: The annealed core material is immersed in a protective agent at 40-50°C for 20-25 minutes, then rinsed with deionized water, subjected to ultrasonic vibration for 15-20 minutes, dried with nitrogen gas, and wound onto a reel to obtain a silver alloy bonding wire. The protective agent contains, by weight, 4 parts ethylene glycol monovinyl ether, 2 parts polyethylene glycol fatty acid ester, 2 parts para-aminobenzoic acid, and 75 parts ethanol.

<Comparative Example 1>
This comparative example provides a method for preparing a silver alloy bonding wire. The core material components and contents (mass fractions) of the prepared silver alloy bonding wire are shown in Table 2.

The method for preparing the above silver alloy bonding wire was as described in Example 1.

<Test Example 1>
The silver alloy bonding wires having a diameter of 20 μm according to Example 1 and Comparative Example 1 were subjected to mechanical property tests, and the results are shown in Table 3.
The tensile breaking strength and elongation tests were based on the IPC-9702 standard.

As can be seen from Table 3, the silver alloy bonding wire of the present invention had superior tensile breaking strength and elongation compared to Comparative Example 1.

Corrosion resistance tests were conducted on silver alloy bonding wires 1# to 11# from Example 1 and Comparative Example 1, and the results are shown in Figure 1.

To test corrosion resistance, the silver alloy bonding wire was immersed in a 0.1 mol/L aqueous solution of sodium sulfide at room temperature, and corrosion resistance data was recorded for 200 hours to obtain a corrosion resistance graph.

As can be seen from Figure 1, the corrosion rate of the silver alloy bonding wire in Example 1 over 200 hours was always maintained at a relatively low level, much lower than that of Comparative Example 1, and the corrosion resistance of silver alloy bonding wire 3# was good.

The above embodiments are merely intended to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art may modify the technical solutions described in the above embodiments and make equivalent substitutions for some or all of the technical features therein. These modifications or substitutions do not deviate from the essence of the relevant technical solutions and the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

Including core material,
The core material contains, by mass fraction, Al: 0.5 wt% to 0.7 wt%, Ce: 0.6 wt% to 1 wt%, carbon nanotubes: 1 wt% to 3 wt%, Sb: 0.3 wt% to 0.5 wt%, and the remainder is Ag. Silver alloy bonding wire. In the core material, the total mass fraction of the Al and the Sb is 1%;
And/or, in the core material, the total mass fraction of the Al, the Ce, the carbon nanotubes, and the Sb is 3.5% or less. The silver alloy bonding wire according to claim 1. The carbon nanotubes include single-walled carbon nanotubes.
And/or, the carbon nanotube has a diameter of 2 nm or less and a length of 50 nm or less, characterized in that the silver alloy bonding wire according to claim 1. Further comprising a protective layer provided on the surface of the core material,
Alternatively, the silver alloy bonding wire according to claim 1 further comprises a protective layer provided on the surface of the core material, wherein the protective layer comprises, by weight, 3 to 5 parts of a film-forming agent, 1 to 3 parts of a surfactant, and 1 to 3 parts of a dissolution aid. the film-forming agent includes at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate;
the surfactant includes at least one of polyethylene glycol fatty acid ester, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate;
The silver alloy bonding wire according to claim 4, characterized in that the dissolution aid contains at least one of para-aminobenzoic acid, acetone, and methanol. The diameter of the core material is 15 to 40 μm.
And/or, the thickness of the protective layer is 1.5 to 4 μm, characterized in that the silver alloy bonding wire according to claim 4. A method for preparing the silver alloy bonding wire according to any one of claims 1 to 6, comprising:
Step S1: melting and pouring the Ag/Ce intermediate alloy, the Sb raw material, the Al foil, and the carbon nanotubes in this order to obtain a rod;
A method for preparing a silver alloy bonding wire, comprising: a step S2 of extruding and drawing the rod material in sequence to obtain the core material. In step S2, the extrusion temperature is 700 to 750 ° C.
And/or, the method for preparing a silver alloy bonding wire as claimed in claim 7, characterized in that the extrusion ratio of the extrusion is 3 to 4.5. (1) further comprising the step of sequentially performing cleaning, annealing, and immersion treatment on the core material to obtain the silver alloy bonding wire;
(2) The annealing temperature is 450 to 500°C;
and (3) the immersion treatment includes immersing the core material after the annealing treatment in a protective agent to obtain a protective layer, and the protective agent includes, by weight, 3 to 5 parts of a film-forming agent, 1 to 3 parts of a surfactant, 1 to 3 parts of a solubilizing agent, and 70 to 80 parts of a solvent;
8. The method for preparing a silver alloy bonding wire according to claim 7, characterized in that it comprises at least one of the following: Use of the silver alloy bonding wire according to any one of claims 1 to 6 in electronic packaging.