Silver alloy bonding wire, and adjustment method and use thereof

Abstract

To provide a silver alloy bonding wire that has excellent dynamic characteristics and corrosion resistance.SOLUTION: The present invention belongs to the technical field of a material for packaging, and relates particularly to a silver alloy bonding wire, and an adjustment method and use thereof. The silver alloy bonding wire according to the present invention includes a core material, and the core material includes 0.5 wt.%-0.7 wt.% of Al, 0.6 wt.%-1 wt.% of Ce, 1 wt.%-3 wt.% of carbon nano-tube, and 0.3 wt.%-0.5 wt.% of Sb, and the remainder is Ag. The silver alloy bonding wire according to the present invention improves the dynamic characteristics, processing performance, corrosion resistance, and electromigration resistance of the silver alloy bonding wire through cooperation of elements, and when used for electronic packaging, can satisfy packaging requirements for an LED device with fine wire diameter processing and a high-density lead.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention belongs to the technical field of packaging materials, and particularly relates to silver alloy bonding wires, a method for preparing the same, and their use.

Background Art

[0002] Wire bonding is the most common and important interconnection method in microelectronic packaging. Bonding wires are packaging inner leads, and are used as welding leads between chips and frames, for connection with pins and silicon wafers, and for transmission of electrical signals. They play the role of electrical connection between chips and external circuits, and are one of the essential basic raw materials in the repackaging manufacturing processes of integrated circuits, semiconductor discrete devices, and LED light source devices. Bonding wires mainly include gold wires, silver wires, aluminum wires, copper wires, etc. Silver wires have good mechanical properties, can reduce the high-frequency noise and heat generation of devices, and are significantly more cost-effective than gold wires.

Summary of the Invention

Problems to be Solved by the Invention

[0003] With the development of semiconductor packaging towards higher density and integration, the reliability of bonding has become more important. However, silver wires have problems such as low connection strength, easy occurrence of electromigration, corrosion and sulfidation of the metal, resulting in reduced reliability and greatly limited applications. In view of this, the present invention has been devised.

[0004] The first object of the present invention is to provide a silver alloy bonding wire having excellent mechanical properties and corrosion resistance.

[0005] A second object of the present invention is to provide a method for preparing a silver alloy bonding wire capable of improving the mechanical properties and corrosion resistance of the bonding wire.

[0006] A third object of the present invention is to provide the use of a silver alloy bonding wire in electronic packaging that can improve the reliability of bonding.

[0007] In order to achieve the above object of the present invention, in particular, the following technical solutions are adopted.

Means for Solving the Problems

[0008] The present invention provides a silver alloy bonding wire. The silver alloy bonding wire includes a core material, and the core material includes, 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 balance is Ag.

[0009] Furthermore, in the core material, the total mass fraction of Al and Sb is 1%, and / or in the core material, the total mass fraction of Al, Ce, the carbon nanotubes, and Sb is 3.5% or less.

[0010] 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.

[0011] Furthermore, it further includes a protective layer provided on the surface of the core material, and / or the protective layer provided on the surface of the core material includes, by weight parts, film-forming agent: 3 to 5 parts, surfactant: 1 to 3 parts, dissolution aid: 1 to 3 parts.

[0012] Furthermore, the film-forming agent contains at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate, the surfactant contains at least one of polyethylene glycol fatty acid ester, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate, and the dissolution aid contains at least one of para-aminobenzoic acid, acetone, and methanol.

[0013] 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.

[0014] The present invention further provides a method for preparing the above silver alloy bonding wire. The preparation method includes step S1 of melting and casting in sequence with an Ag / Ce intermediate alloy, an Sb raw material, an Al foil, and the carbon nanotube, and performing pouring to obtain a bar, and step S2 of performing extrusion and drawing in sequence on the bar to obtain the core material.

[0015] Furthermore, in step S2, the extrusion temperature is 700 to 750 °C, and / or the extrusion ratio of the extrusion is 3 to 4.5.

[0016] Furthermore, the method for preparing the silver alloy bonding wire further includes (1) successively performing cleaning, annealing treatment, and dipping treatment on the core material to obtain the silver alloy bonding wire, (2) the annealing treatment temperature is 450 to 500 °C, and (3) the dipping treatment includes dipping the core material after the annealing treatment in a protective agent to obtain a protective layer, and the protective agent contains, by weight, 3 to 5 parts of a film-forming agent, 1 to 3 parts of a surfactant, 1 to 3 parts of a dissolution aid, and 70 to 80 parts of a solvent, including at least one of them.

[0017] The present invention further provides the use of the above silver alloy bonding wire or the silver alloy bonding wire prepared by the above method for preparing a silver alloy bonding wire in electronic packaging.

[0018] Compared with the prior art, the present invention has the following beneficial effects. 1. The silver alloy bonding wire according to the present invention adds Sb element and carbon nanotubes to the silver alloy, and through the cooperation with Ce element and Al element, it improves the mechanical properties, processing performance, electromigration resistance and corrosion resistance of the silver alloy bonding wire, and can meet the packaging requirements of micro wire diameter processing and high-density lead LED devices. 2. The silver alloy bonding wire according to the present invention further improves the corrosion protection performance of the silver alloy bonding wire by providing a protective layer on the surface of the core material, and can prevent the sulfidation and corrosion of the core material. 3. The preparation method of 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, casting and extrusion.

Brief Description of the Drawings

[0019] To more clearly explain 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 are briefly described below. The drawings to be 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 capabilities.

Figure 1

Modes for Carrying Out the Invention

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the drawings and specific embodiments. As will be understood by those skilled in the art, the described embodiments are only some embodiments of the present invention, not all embodiments, and are only for explaining the present invention, not for limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without using inventive capabilities also belong to the protection scope of the present invention. In the embodiments, for the case where specific conditions are not specified, it is possible to carry out under conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, commercially available conventional products can be used.

[0021] It should be noted that the term "and / or" used in this specification represents the relationship of related objects, indicating that there are three kinds of relationships. For example, A and / or B represents three relationships: only A exists, both A and B exist, and only B exists.

[0022] Some embodiments of the present invention provide a silver alloy bonding wire. The silver alloy bonding wire includes a core material, and the core material contains, by mass fraction, Al: 0.5 wt% - 0.7 wt%, Ce: 0.6 wt% - 1 wt%, carbon nanotubes: 1 wt% - 3 wt%, Sb: 0.3 wt% - 0.5 wt%, and the balance is Ag.

[0023] The silver alloy bonding wire according to the present invention can solve the problems of silver wires such as low connection strength, easy occurrence of electromigration, and corrosion and sulfidation of the metal. The silver alloy bonding wire according to the present invention has excellent mechanical properties, processing performance, electromigration resistance, and sulfidation and corrosion resistance, and can meet the packaging requirements of micro wire diameter processing and high-density lead LED devices.

[0024] In the silver alloy bonding wire according to the present invention, by adding Al element, a dense protective layer is formed on the surface of silver, the surface is passivated, the corrosion resistance of the silver alloy wire can be improved. By adding Ce element, the corrosion resistance can be improved, the growth rate and diffusion rate of IMC at the Ag / Al interface are increased, the bonding reliability is improved. By adding carbon nanotubes, the thermal conductivity can be increased and the electron mobility can be decreased. And the carbon nanotubes, as a nano-strengthening phase, promote the increase of nucleation sites in the non-spontaneous nucleation mode of the silver metal liquid, thereby refining the crystal grains and increasing the strength of the bonding wire. By adding Sb element, the Sb element accumulates at the grain boundaries, thereby reducing the diffusion effect along the grain boundaries and improving the strength and electromigration resistance.

[0025] In some embodiments of the present invention, by way of example and not limitation, for instance, in the core material, the mass fraction of Al is a value within the range of 0.5wt%, 0.55wt%, 0.6wt%, 0.65wt%, 0.7wt%, or a value within the range consisting of any two of these values; the mass fraction of Ce is a value within the range of 0.6wt%, 0.65wt%, 0.7wt%, 0.75wt%, 0.8wt%, 0.85wt%, 0.9wt%, 0.95wt%, 1wt%, or a value within the range consisting of any two of these values; the mass fraction of carbon nanotubes is a value within the range of 1wt%, 1.2wt%, 1.4wt%, 1.6wt%, 1.8wt%, 2wt%, 2.2wt%, 2.4wt%, 2.6wt%, 2.8wt%, 3wt%, or a value within the range consisting of any two of these values; the mass fraction of Sb is a value within the range of 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt%, 0.5wt%, or a value within the range consisting of any two of these values.

[0026] The present invention further optimizes the composition of the core material in the silver alloy bonding wire in order to improve the mechanical properties and corrosion resistance of the silver alloy bonding wire.

[0027] In some embodiments of the present invention, the core material contains, by mass fraction, Al: 0.55 wt% to 0.65 wt%, Ce: 0.75 wt% to 0.85 wt%, carbon nanotubes: 1.1 wt% to 1.3 wt%, Sb: 0.3 wt% to 0.5 wt%, and the balance is Ag.

[0028] In some embodiments of the present invention, the total mass fraction of Al and Sb in the core material is 1%.

[0029] 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.

[0030] In some embodiments of the present invention, the carbon nanotubes include single-walled carbon nanotubes.

[0031] 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.

[0032] If carbon nanotubes of the above size are adopted, the carbon nanotubes can be uniformly distributed in the alloy. When the bonding wire is drawn to an extremely thin state, if the size of the carbon nanotubes is relatively large, it is disadvantageous for the deformation and drawing of the alloy, and the mechanical properties are inferior.

[0033] In some embodiments of the present invention, the bonding wire further includes a protective layer provided on the surface of the core material.

[0034] In some embodiments of the present invention, the protective layer contains, by parts by weight, film-forming agent: 3 to 5 parts, surfactant: 1 to 3 parts, dissolution aid: 1 to 3 parts.

[0035] In some embodiments of the present invention, the film-forming agent includes at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate, but is not limited thereto.

[0036] In some embodiments of the present invention, the surfactant includes, but is not limited to, at least one of polyethylene glycol fatty acid ester, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate.

[0037] In some embodiments of the present invention, the solubilizer includes, but is not limited to, at least one of para - aminobenzoic acid, acetone, and methanol. Para - aminobenzoic acid can play a role in removing dirt, oil, etc. and corrosion prevention.

[0038] The protective layer according to the present invention can prevent the 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.

[0039] In some embodiments of the present invention, the protective layer contains, by weight parts, ethylene glycol monovinyl ether: 3 - 5 parts, polyethylene glycol fatty acid ester: 1 - 3 parts, para - aminobenzoic acid: 1 - 3 parts.

[0040] In some embodiments of the present invention, the diameter of the core material is 15 - 40 μm. Typically and non - restrictively, for example, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or a value within the range composed of any two of these values. The thickness of the protective layer is 1.5 - 4 μm. Typically and non - restrictively, for example, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, or a value within the range composed of any two of these values.

[0041] In some embodiments of the present invention, the tensile breaking force of the silver alloy bonding wire is 9 - 10 g.

[0042] In some embodiments of the present invention, the elongation rate of the silver alloy bonding wire is 9% - 12%, preferably 10.5% - 12%.

[0043] Some embodiments of the present invention further provide a method for preparing the above silver alloy bonding wire. The preparation method includes the following steps.

[0044] Step S1: Melting and casting are sequentially performed on an Ag / Ce intermediate alloy, an Sb raw material, an Al foil, and carbon nanotubes to obtain a bar.

[0045] Step S2: Extrusion and drawing are sequentially performed on the above bar to obtain a core material.

[0046] The method for preparing a 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, casting, and extrusion.

[0047] In some embodiments of the present invention, the method for preparing the Ag / Ce intermediate alloy in Step S1 includes the following.

[0048] Weigh an Ag raw material and a Ce raw material according to the mixing ratio and put them into a crucible in a vacuum furnace. Close the furnace door and evacuate to 3×10 -2 Pa, introduce argon gas to 0.1 - 0.3 Pa, and when heating up to 600 - 800 °C, repeat the evacuation operation and the argon gas introduction operation three times. Then, heat up to 1200 - 1250 °C, stir for 3 - 5 min, refine for 10 - 15 min, perform a degassing operation, and cool 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 over 99.99%.

[0049] In some embodiments of the present invention, in Step S1, put the Ag / Ce intermediate alloy, the Sb raw material, the Al foil, and the carbon nanotubes into a vacuum melting furnace, 2×10 -2Evacuate to Pa, then introduce argon gas to 0.1 - 0.3 Pa, repeat the evacuation operation and argon gas introduction operation three times, then heat up to 1250 - 1300 °C, stir for 15 - 20 min using a magnetic stirrer, and when cooling down to 1150 - 1200 °C, form a bar with a diameter of 30 - 50 mm by pouring molten metal.

[0050] In some embodiments of the present invention, as the addition method of the Al foil and the carbon nanotubes in step S1, carbon nanotube powder is laid on the Al foil, and then sandwiched and folded by two Al foils for addition.

[0051] In some embodiments of the present invention, in step S2, the extrusion temperature is 700 - 750 °C, and the extrusion ratio is 3 - 4.5. Preferably, the extrusion includes the following. Place the bar in the container of the extruder, heat it up to 700 - 750 °C and perform heat preservation treatment for 2 h, the extrusion speed of the bar is 3 - 4 mm / s, the extrusion ratio is 3 - 4.5, the rotation speed of the extrusion wheel is 5 - 7 r / min, and obtain a bar with a diameter of 5 - 10 mm by extrusion.

[0052] The present invention utilizes degassing, refining, and bar pouring, uses peeling extrusion instead of continuous casting for the bar, further increases the density and strength.

[0053] In some embodiments of the present invention, the drawing includes at least two wire drawing processes, and heat treatment is performed each time after wire drawing to perform the next wire drawing process. Preferably, the drawing includes performing the first wire drawing process, heat treatment, and the second wire drawing process in sequence.

[0054] In some embodiments of the present invention, in step S2, the first wire drawing process includes making the bar after extrusion into a wire with a diameter of 0.8 - 1.1 mm by a wire drawing machine, the reduction rate per pass of the extrusion is 15% - 18%, and the wire drawing speed is 1.2 - 1.8 m / s.

[0055] In some embodiments of the present invention, the heat treatment in step S2 includes the following. A wire with a diameter of 0.8 to 1.1 mm is placed in a vacuum annealing furnace, and the temperature is raised to 350 to 400 °C at a rate of 2 to 3.5 °C / s under a vacuum degree of 3×10 -2 ~5×10 -2 Pa, heat-treated for 3 to 5 h, and then furnace-cooled to 80 °C or lower.

[0056] In some embodiments of the present invention, the second wire drawing process in step S2 includes the following. The wire after heat treatment is subjected to drawing and extraction using a multi-wire drawing machine, and a core material with a wire diameter of 15 to 40 μm is obtained by drawing and extraction of the thin wire. Preferably, in the process of drawing and extraction by the multi-wire drawing machine, the reduction rate per pass is 10% to 13%, and the wire drawing speed is 2 to 2.5 m / s. In the process of drawing and extraction of the thin wire, the diameter reduction rate is 15% to 18%, and the wire drawing speed is 3 to 5 m / s.

[0057] In some embodiments of the present invention, the method for preparing a silver alloy bonding wire further includes the steps of sequentially performing cleaning, annealing treatment, and dipping treatment on the core material to obtain a silver alloy bonding wire.

[0058] In some embodiments of the present invention, the annealing includes the following. The core material after cleaning is passed through an in-line annealing device equipped with an antioxidant droplet dropping device, the passing speed is 2.5 to 3 m / s, and the annealing temperature is 450 to 500 °C.

[0059] Annealing can consume the work hardening of the previous process, improve the stability and reliability of the bonding wire, and improve the mechanical strength of the bonding wire, so that the bonding wire can withstand a greater tensile breaking force. The resistivity and conductivity of the bonding wire deeply depend on its crystal structure and lattice defects. Annealing can promote the growth of crystal grains and the repair of lattice defects, thereby improving the electrical performance and conductivity of the bonding wire.

[0060] In some embodiments of the present invention, the dipping treatment includes dipping the core material after the annealing treatment into a protective agent to obtain a protective layer.

[0061] The protective agent contains, by parts by weight, 3 - 5 parts of a film-forming agent, 1 - 3 parts of a surfactant, 1 - 3 parts of a dissolution aid, and 70 - 80 parts of a solvent.

[0062] In some embodiments of the present invention, the solvent includes, but is not limited to, ethanol.

[0063] In some embodiments of the present invention, the dipping treatment has a time of 20 - 25 min and a temperature of 40 - 50 °C.

[0064] In some embodiments of the present invention, the cleaning includes immersing the core material in deionized water and performing ultrasonic vibration for 5 - 10 min to remove surface dirt.

[0065] In some embodiments of the present invention, after the dipping treatment, it further includes the steps of cleaning with deionized water, performing ultrasonic vibration for 15 - 20 min, drying with nitrogen gas, and winding onto a reel.

[0066] Some embodiments of the present invention further provide the use of the above silver alloy bonding wire or the silver alloy bonding wire prepared by the above method for preparing a silver alloy bonding wire in electronic packaging.

[0067] <Example 1> This example provided a method for preparing a silver alloy bonding wire. The core material components and contents (mass fraction) of the prepared silver alloy bonding wire are shown in Table 1.

[0068]

Table 1

[0069] Specifically, the method for preparing the above silver alloy bonding wire includes the following steps.

[0070] Step S1: Put Ag raw materials with a purity exceeding 99.99% and Ce raw materials with a purity exceeding 99.9% into the crucible of a vacuum melting furnace, close the furnace door, evacuate to 2×10 -2 Pa, introduce argon gas to 0.1 - 0.3 Pa, repeat the evacuation operation and argon gas introduction operation three times, then heat the furnace body to 1200 - 1250 °C, stir for 3 - 5 min, keep warm and refine for 10 - 15 min, perform a degassing operation, and then cool the furnace to room temperature to obtain an Ag / Ce intermediate alloy.

[0071] Step S2: Mix an Ag / Ce intermediate alloy, Sb raw materials with a purity of 99.99%, and carbon nanotubes (single - wall carbon nanotubes, diameter ≤ 2 nm, length ≤ 50 nm) coated with Al foil (the purity of the Al foil is 99.99%, carbon nanotube powder is laid on the Al foil, and it is added after being folded and clamped by two Al foils) according to the mixing ratio, put them into a vacuum melting furnace, evacuate to 2×10 -2 Pa, then introduce argon gas to 0.1 - 0.3 Pa, repeat the evacuation operation and argon gas introduction operation three times, and then heat to 1250 - 1300 °C, stir for 15 - 20 min using a magnetic stirrer, and when cooling down to 1150 °C - 1200 °C, form a bar with a diameter of 30 - 50 mm by pouring.

[0072] Step S3: Place the bar with a diameter of 30 - 50 mm in the container of an extruder, heat to 700 - 750 °C and keep warm for 2 h. After extrusion, cut off the head and tail parts to obtain a bar with a diameter of 5 - 10 mm. The extrusion speed of the bar is 3 - 4 mm / s, the extrusion ratio is 3 - 4.5, and the rotation speed of the extrusion wheel is 5 - 7 r / min.

[0073] Step S4: Use a wire drawing machine to make the bar with a diameter of 5 - 10 mm into a wire with a diameter of 0.8 - 1.1 mm. The reduction rate per pass is 15% - 18%, and the wire drawing speed is 1.2 - 1.8 m / s.

[0074] Step S5: Put the wire with a diameter of 0.8 - 1.1 mm into a vacuum annealing furnace, heat it up to 350 - 400 °C at a rate of 2 - 3.5 °C / s under a vacuum degree of 3×10 -2 ~5×10 -2 Pa for 3 - 5 h of heat treatment, then cool it in the furnace to below 80 °C and take it out of the furnace.

[0075] Step S6: Use a multi - wire drawing machine to draw the heat - treated wire by drawing to a wire with a diameter of 0.1 mm or less. The reduction rate per pass is 10% - 13%, and the wire drawing speed is 2 - 2.5 m / s.

[0076] Step S7: Perform fine - wire drawing on the wire with a diameter of 0.1 mm or less to obtain a core material with a diameter of 15 μm. The diameter reduction rate is 15% - 18%, and the wire drawing speed is 3 - 5 m / s.

[0077] Step S8: Immerse the core material in deionized water and perform ultrasonic vibration for 5 - 10 min to remove surface dirt.

[0078] Step S9: Pass the washed core material through an in - line annealing device equipped with an antioxidant droplet - dropping device. The wire speed is 2.5 - 3 m / s, and the annealing temperature is 450 - 500 °C.

[0079] Step S10: Immerse the annealed core material in a protective agent, immerse it at 40 - 50 °C for 20 - 25 min, then wash it with deionized water, perform ultrasonic vibration for 15 - 20 min, dry it with nitrogen gas, and wind it on a reel to obtain silver alloy bonding wire. The protective agent contains, by weight, 4 parts of ethylene glycol monovinyl ether, 2 parts of polyethylene glycol fatty acid ester, 2 parts of para - aminobenzoic acid, and 75 parts of ethanol.

[0080] <Comparative Example 1> This comparative example provides a method for preparing silver alloy bonding wire. The core material components and contents (mass fraction) of the silver alloy bonding wire that can be prepared are shown in Table 2.

[0081]

Table 2

[0082] The preparation method of the above silver alloy bonding wire referred to Example 1.

[0083] <Test Example 1> Mechanical property tests were conducted on the silver alloy bonding wires with a diameter of 20 μm according to each of Example 1 and Comparative Example 1, and the results are shown in Table 3. The tests of tensile breaking force and elongation rate referred to the IPC-9702 standard.

[0084]

Table 3

[0085] As can be seen from Table 3, for Comparative Example 1, the silver alloy bonding wire according to the present invention has more excellent tensile breaking force and elongation rate.

[0086] Corrosion resistance tests were conducted on the silver alloy bonding wires 1# to 11# according to each of Example 1 and Comparative Example 1, and the results are shown in FIG. 1.

[0087] As a corrosion resistance test method, the silver alloy bonding wire was immersed in a 0.1 mol / L sodium sulfide aqueous solution at room temperature, and the corrosion resistance data for 200 h were recorded to obtain a corrosion resistance graph.

[0088] As can be seen from FIG. 1, the corrosion rate of the silver alloy bonding wire according to Example 1 for 200 h was always maintained at a relatively low level and was much smaller than that of Comparative Example 1, and the corrosion resistance of the silver alloy bonding wire 3# was good.

[0089] Each of the above embodiments is merely for explaining the technical solution of the present invention and does not limit it. Although the present invention has been described in detail with reference to each of the above embodiments, those skilled in the art may modify the technical solutions described in each of the above embodiments, or may perform equivalent substitutions for some or all of the technical features therein. These modifications or substitutions do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of each embodiment of the present invention.

Claims

1. Including the 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. This silver alloy bonding wire is characterized by the above.

2. 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, characterized in that

3. 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.

4. 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, the protective layer comprising, 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.

5. the film-forming agent includes at least one of ethylene glycol monovinyl ether, polyacrylate, and polyvinyl acetate; the surfactant comprises at least one of a 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.

6. 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.

7. A method for preparing the silver alloy bonding wire according to any one of claims 1 to 6, comprising the steps of: Step S1 of melting and pouring the Ag / Ce intermediate alloy, the Sb raw material, the Al foil, and the carbon nanotubes in order to obtain a rod; A method for preparing a silver alloy bonding wire, comprising the steps of: (S2) sequentially extruding and drawing the rod material to obtain the core material.

8. 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 3-4.

5.

9. (1) The method further includes 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, further comprising at least one of:

10. 7. Use of the silver alloy bonding wire according to any one of claims 1 to 6 in electronic packaging.

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