Bonding aluminum wire for integrated circuit package and method for manufacturing the same

Abstract

The present application relates to the technical field of metal alloy, and particularly relates to a bonding aluminum wire for integrated circuit packaging and a preparation method thereof, the bonding aluminum wire is composed of a composite aluminum alloy, the alloy is composed of zirconium, lanthanum, ytterbium, gallium and copper in an aluminum-silicon matrix, through the chemical component design, a double-zone collaborative microstructure is constructed in the alloy: that is, three aluminum zirconium nanophase which is coherent with the aluminum matrix is dispersedly distributed in the grain, and the solute atoms such as lanthanum and ytterbium are segregated at the grain boundary, through the above-mentioned stable mechanism of partitioning and collaboration in two dimensions of grain and grain boundary, the problem of high temperature softening of the traditional aluminum wire is solved, the high temperature strength and the fatigue resistance are improved without sacrificing the excellent conductivity of the material, and the alloy has self-repairing and self-healing ability under bonding damage and extreme thermal shock, and the service reliability of the whole life cycle is enhanced.

Description

TECHNICAL FIELD

[0001] The application relates to a bonding aluminum wire for integrated circuit packaging and a preparation method thereof, and belongs to the technical field of metal alloys. BACKGROUND

[0002] High-purity aluminum-based bonding wires have been widely used as mainstream electrical interconnection materials for a long time due to excellent electrical conductivity, low cost and mature bonding process. In order to solve the problem of insufficient mechanical strength of pure aluminum, especially easy creep at high temperature, about 1% of silicon by weight is generally added to high-purity aluminum to form a classic Al-1%Si alloy. In order to improve the poor processability, difficult-to-achieve strength and elongation of the traditional Al-1%Si alloy bonding wire caused by coarse and uneven Si particles, a series of process improvements have been made in the prior art. For example, a Chinese patent for invention with the authorization announcement number CN101332477B discloses a manufacturing method of a silicon-aluminum bonding wire for semiconductor devices. By adopting horizontal continuous casting to form a single-direction columnar crystal organization, and combining a two-step heat treatment process of homogenization treatment and intermediate solid solution treatment, the manufacturing process is optimized, the aluminum wire product with fine Si particles and high strength and elongation is obtained, and the comprehensive performance of the Al-1%Si alloy wire is improved to a certain extent.

[0003] However, the essence of the above technical solutions is still the process improvement of the existing Al-1%Si alloy, and the material matrix is not changed. Therefore, with the rise of the third generation of semiconductor power devices represented by silicon carbide and gallium nitride, the working junction temperature of the chip is pushed to a harsh range of 175 to 200 degrees Celsius or above, and needs to withstand more frequent and severe power cycle impacts. The Chinese invention patent with the authorization announcement number CN101332477B discloses a semiconductor device silicon-aluminum bonding wire manufacturing method. The Al-1%Si alloy bonding wire disclosed in the patent is placed in such a high temperature-cycle stress coupling working condition, and the silicon phase particles used for strengthening will quickly coarsen and spheroidize at high temperature, gradually losing the effective pinning effect on the grain boundary. At the same time, the aluminum matrix itself will also undergo dynamic recovery and recrystallization at high temperature, causing the grains to grow rapidly and the matrix strength to decrease. The superposition of these two failure mechanisms causes the Al-1%Si alloy wire, even after process optimization, to still experience catastrophic performance degradation in the heat-affected zone near the solder joint, and its long-term reliability cannot meet the requirements of the new generation of power semiconductors. In the face of this challenge, one option is to continue using the old strengthening method and adding more silicon or other hard strengthening phases to the alloy, but this will inevitably introduce more electron scattering centers and lattice distortions, significantly degrading the electrical and thermal conductivity of the aluminum wire and increasing its hardness, which worsens the bonding process window. Another approach is to return to pure aluminum to achieve the best electrical conductivity and process performance, but this makes it unable to withstand mechanical stress at high temperatures. Specifically, the existing technology mainly has the following deficiencies: 1. The strengthening mechanism is weak at high temperatures and cannot maintain long-term structural stability under high-temperature cyclic conditions; 2. There is a difficult to reconcile relationship between the high-temperature strength, electrical conductivity, and bonding process of the material; 3. There is a lack of a new mechanism that can effectively suppress the softening of the aluminum matrix at high temperatures without introducing a large number of defects and significantly sacrificing electrical conductivity. Therefore, how to design a microstructure stabilization mechanism that can strengthen the alloy by introducing a hard second phase, while maintaining the excellent electrical conductivity and process performance of the aluminum matrix, and achieving structural self-stabilization of the alloy at high temperatures, has become a technical problem to be solved by the present application. SUMMARY

[0004] The present application provides a kind of integrated circuit package bonding aluminum wire and its preparation method, its main purpose is to solve the existing bonding aluminum wire alloy Because of the inherent limitations of its strengthening mechanism, there is structural instability and performance degradation under high temperature working conditions, and there is a difficult to reconcile contradiction between its strength, electrical conductivity and process.

[0005] To achieve the above purpose, the present application provides a kind of integrated circuit package bonding aluminum wire, which is composed of an aluminum alloy, the aluminum alloy takes aluminum as matrix, and contains, by weight percentage,

[0006] 0.5% to 1.2% silicon; 0.05% to 0.15% zirconium; 0.01% to 0.08% lanthanum and ytterbium in total; 0.005% to 0.05% gallium; and 0.1% to 0.5% copper;

[0007] In aluminum alloys, the weight ratio of lanthanum to ytterbium is in the range of 1:3 to 3:1, and the ratio of the total weight of lanthanum and ytterbium to the weight of zirconium is in the range of 0.1 to 1.0.

[0008] In the microstructure of aluminum alloy, the zirconium trialuminate nanophase, which is coherent with the aluminum matrix, is dispersed inside the aluminum matrix grains. The average equivalent diameter of the zirconium trialuminate nanophase is no more than 20 nanometers, and the number density is no less than one to the power of 10 to the power of 21 per cubic meter.

[0009] At the grain boundaries of the aluminum matrix, solute atoms of lanthanum and ytterbium are segregated; gallium exists in the lattice of the aluminum matrix in the form of solid solution atoms; copper, aluminum matrix and silicon together form an Al-Si-Cu ternary low eutectic structure at the grain boundaries of the aluminum matrix, and the melting point of the Al-Si-Cu ternary low eutectic structure is in the range of 520℃ to 550℃.

[0010] Preferably, the Al-Si-Cu ternary low eutectic structure is discontinuously distributed in the microstructure of the aluminum alloy, and the Al-Si-Cu ternary low eutectic structure and the zirconium trialuminate nanophase have a lattice mismatch of less than 5% required for heterogeneous nucleation.

[0011] Preferably, the aluminum alloy further comprises 0.01% to 0.1% by weight of hafnium, which, together with lanthanum and ytterbium, segregates at the grain boundaries of the aluminum matrix and forms local chemical bonds with the surrounding aluminum atoms.

[0012] Preferably, in the aluminum alloy, the ratio of the sum of the weight percentage concentrations of lanthanum and ytterbium to the sum of the weight percentage concentrations of zirconium and hafnium satisfies the constraint defined by the following relationship: 0.2≤(C_La+C_Yb) / (C_Zr+C_Hf)≤1.5; where C_La is the weight percentage concentration of lanthanum, C_Yb is the weight percentage concentration of ytterbium, C_Zr is the weight percentage concentration of zirconium, and C_Hf is the weight percentage concentration of hafnium.

[0013] Preferably, the aluminum alloy further comprises 0.01% to 0.05% by weight of scandium and 0.005% to 0.02% by weight of tin; scandium partially forms scandium trialuminide phase in the microstructure of the aluminum alloy as heterogeneous nucleation core of zirconium trialuminide nanophase; tin is enriched at the grain boundaries of the aluminum matrix in the microstructure of the aluminum alloy.

[0014] Preferably, the aluminum alloy obtains a microstructure after being prepared by a final annealing process. The parameters of the final annealing process are: a heating rate of 0.5℃ / s to 5℃ / s, a holding temperature of 150℃ to 250℃, and a holding time of 1 minute to 30 minutes.

[0015] Preferably, the room temperature resistivity of the bonded aluminum wire is not higher than 2.95 μΩ·cm.

[0016] Preferably, the tensile strength of the bonded aluminum wire measured at 200°C is more than 70% of the tensile strength measured at room temperature, and the aluminum alloy uses aluminum with a purity of not less than 99.99% as the matrix.

[0017] Preferably, the finished diameter of the bonded aluminum wire is 10 micrometers to 50 micrometers.

[0018] A method for preparing bonding aluminum wire for integrated circuit packaging, the method comprising:

[0019] An aluminum alloy ingot is provided, the aluminum alloy ingot being composed of the aforementioned aluminum alloy;

[0020] The aluminum alloy ingot is drawn into a wire to form a semi-finished aluminum wire. The cumulative true strain of the drawing process is not less than 3.0.

[0021] The aluminum wire semi-finished product is subjected to final annealing treatment to obtain bonded aluminum wire; the process parameters for the final annealing treatment are: heating rate of 0.5℃ / s to 5℃ / s, holding temperature of 150℃ to 250℃, and holding time of 1 minute to 30 minutes.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. The alloy of the present invention, through the composite addition of multiple trace elements such as zirconium, lanthanum, and ytterbium, constructs a stable mechanism of microstructural partitioning and synergy in an aluminum matrix. Among them, lanthanum and ytterbium, due to their differences in atomic size and diffusion characteristics, form solute atom segregation at grain boundaries, increasing the kinetic resistance to grain boundary migration. This process does not depend on the pinning of second-phase particles, avoiding the influence of a large number of scattering interfaces on the conductivity of the material. At the same time, zirconium reacts in situ with the aluminum matrix inside the grains to form a zirconium trialuminate nanophase coherent with the matrix lattice. This nanophase, while hindering the movement of dislocations within the grains, weakens the scattering effect on conduction electrons because it maintains the continuity of the lattice with the matrix. These two mechanisms work in a spatial partitioning manner and complement each other in function, making it possible to maintain the long-term mutually restrictive properties of strength and conductivity at high temperatures in a parallel manner.

[0024] 2. The alloy composition of the present invention further includes trace amounts of gallium, providing a path for damage self-passivation of the bonding wire during the intense plastic deformation process of ultrasonic bonding. Under the enormous energy applied at the moment of bonding, gallium atoms dissolved in the aluminum matrix will obtain extremely high mobility and preferentially segregate to high-energy defect regions such as newly generated dislocation vacancy groups at the neck of the solder joint. The presence of gallium atoms temporarily and locally weakens the metallic bonds between surrounding aluminum atoms, reducing the energy barrier for aluminum atoms to rearrange and slip, allowing the huge internal stress accumulated in this area due to intense deformation to be released rapidly. In a very short time after the ultrasonic energy is removed, the aluminum atoms with released stress will spontaneously rearrange into a more stable and lower-energy lattice structure. This rearrangement process will eliminate most of the original vacancies and nanoscale microcracks, thereby allowing the bonding interface, a weak link caused by the manufacturing process, to reach a stable state with lower internal stress and a denser structure at the beginning of forming.

[0025] 3. The addition of trace amounts of copper to the alloy composition enables the alloy's microstructure to possess self-healing and recovery capabilities after undergoing supercritical thermal shock at temperatures far exceeding conventional operating temperatures. The addition of copper forms a low-melting-point ternary eutectic structure with the existing silicon and aluminum at the grain boundaries. When the temperature spikes instantaneously, this structure will be the first to undergo instantaneous melting, forming a nanoscale transient liquid phase film. This liquid phase can instantly absorb and unload the enormous stress generated by the severe thermal expansion mismatch and fill any nanoscale cracks that may have already begun. When the temperature drops sharply, this liquid phase quickly resolidifies. The copper-rich region formed after solidification, due to its good lattice matching relationship with the zirconium trialuminate nanophase, becomes a preferential nucleation site for the regeneration of the zirconium trialuminate nanophase, thereby capturing the zirconium atoms that were partially dissolved during the thermal shock and reprecipitating them as finer and more dispersed secondary strengthening phases, thus avoiding permanent performance degradation. Attached Figure Description

[0026] Figure 1 This is a diagram showing the relationship between the synergistic function and performance gain of alloying elements in this invention.

[0027] Figure 2 This is a graph showing the optimized relationship between copper content and self-healing effect and electrical properties in this invention.

[0028] Figure 3 This is a schematic diagram of the spatial distribution of the functional phases in the polycrystalline microstructure of the present invention;

[0029] Figure 4 This is a diagram showing the chemical composition and microstructure design elements of the alloy of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] This invention discloses a bonding aluminum wire for integrated circuit packaging and its preparation method. The method, through specific chemical composition design and precise control of thermodynamic processing, constructs a partitioned and synergistic microstructure within an aluminum matrix. This structure includes elements responsible for high-temperature structural stability, elements responsible for repairing bonding interface damage, elements responsible for withstanding extreme thermal shock, and elements responsible for optimizing the manufacturing process window. Under specific wire drawing and final product annealing processes, the functions of each component are realized, ultimately obtaining a bonding aluminum wire that maintains stable performance under high temperature, high stress cycling, and high current density. This addresses the shortcomings of existing... The problem of decreased mechanical properties of Al-1%Si bonded wires at operating temperatures above 175°C due to matrix recrystallization and coarsening of second-phase particles is addressed in this solution by constructing a dual-zone stabilized microstructure in the aluminum matrix. This structure is composed of solute atom pinning at grain boundaries and coherent nanophase dispersion reinforcement within the grains. Specifically, lanthanum (La) and ytterbium (Yb) are added to the alloy in a total content of 0.01% to 0.08% by weight, with their weight ratio controlled in the range of 1:3 to 3:1, and the weight ratio of the total weight of lanthanum and ytterbium to zirconium in the range of 0.1 to 1.0. Utilizing the significant size difference between these two types of atoms and aluminum atoms, they are caused to segregate towards the grain boundaries during the final annealing stage, forming solute atom clusters. These clusters act as a drag on grain boundary migration, effectively inhibiting grain growth at high temperatures. When the total rare earth element content is below 0.01%, the solute atom concentration at the grain boundaries is insufficient to form effective pinning resistance, while above 0.08%, there is a risk of precipitating brittle intermetallic compounds. Simultaneously, by adding 0.05% to 0.15% by weight of zirconium (Zr), it reacts with the aluminum matrix during the final annealing process, dispersing and precipitating within the grains in a coherent manner with the matrix. The zirconium trialuminate nanophase has an average equivalent diameter of no more than 20 nanometers and a number density of no less than 1 x 10^21 per cubic meter. As an obstacle to dislocation movement, it effectively hinders the creep of the material at high temperatures. When the zirconium content is less than 0.05%, the volume fraction of the precipitated phase is insufficient to provide effective reinforcement, while when it is greater than 0.15%, the precipitated phase is prone to coarsening and may transform into an incoherent phase, thereby increasing electron scattering and affecting conductivity. The two mechanisms mentioned above work synergistically in the grain boundary and intragranular regions, so that the tensile strength of the bonding wire can be maintained at more than 70% of that at room temperature when the temperature is 200℃.

[0032] Given that during ultrasonic bonding, the neck of the bonding wire accumulates a large number of lattice defects due to severe plastic deformation, this solution further includes 0.005% to 0.05% by weight of gallium (Ga) in the alloy to passivate such damage. Gallium exists in the aluminum matrix in solid solution form. Under the ultrasonic energy applied during bonding, the solid-solid gallium atoms gain high mobility and rapidly accumulate in high-energy defect regions such as dislocation vacancies. In these regions, the presence of gallium atoms locally reduces the bonding energy between surrounding aluminum atoms, promoting rapid stress relaxation and atomic rearrangement. Therefore, after bonding is completed, the alloy... The region forms a stable state with lower defect density and a denser structure. To address the potential microstructural damage caused by the instantaneous rise in junction temperature to over 500°C under fault conditions such as short circuits in power devices, this solution incorporates 0.1% to 0.5% by weight of copper (Cu) into the alloy to create a self-healing mechanism for the microstructure. The copper, along with aluminum and 0.5% to 1.2% silicon in the matrix, together form an Al-Si-Cu ternary low eutectic structure with a melting point in the range of 520°C to 550°C at the grain boundaries. When thermal shock causes the temperature to exceed this eutectic point, this structure instantly melts to form nanoscale structures. A liquid-phase thin film is used to fill microcracks induced by thermal stress. When the temperature drops sharply, the liquid phase solidifies rapidly, and the resulting copper-rich region, with a lattice mismatch of less than 5% with the zirconium trialuminate nanophase, can serve as a heterogeneous nucleation site for the regeneration of the zirconium trialuminate nanophase. This captures zirconium atoms dissolved during thermal shock and re-precipitates finer secondary strengthening phases, thereby restoring the core strengthening structure. To improve the reliability of the bonding wire under high current density and suppress electromigration failure, this scheme further includes 0.01% to 0.1% by weight of hafnium (Hf) in the alloy composition. Hafnium, along with lanthanum and ytterbium, segregates on the aluminum matrix. At the grain boundaries of the bulk, in addition to providing a mechanical drag effect due to the large atomic mass, the local chemical bonds formed between hafnium atoms and surrounding aluminum atoms also change the electronic state of the grain boundaries, increasing the activation energy required for aluminum atoms to migrate under the action of electron wind, thereby effectively reducing the electromigration rate and satisfying the constraint defined by the relation 0.2≤(C_La+C_Yb) / (C_Zr+C_Hf)≤1.5, where C_La is the weight percentage concentration of lanthanum, C_Yb is the weight percentage concentration of ytterbium, C_Zr is the weight percentage concentration of zirconium, and C_Hf is the weight percentage concentration of hafnium.

[0033] It should be noted that, in order to achieve the synergistic effect of grain boundary stabilization and intragranular stabilization, the weight percentage concentrations of key elements in the alloy must also satisfy a certain ratio. Specifically, the constraint defined by the formula 0.2≤(C_La+C_Yb) / (C_Zr+C_Hf)≤1.5 characterizes the balance between the grain boundary dragging stabilization mechanism and the intragranular and grain boundary pinning stabilization mechanisms. Here, the numerator C_La+C_Yb represents the concentration of the main component providing the grain boundary solute atom dragging effect, while the denominator C_Zr... +C_Hf represents the concentration of components providing intragranular coherent phase pinning (mainly contributed by Zr) and grain boundary chemical anchor pinning (mainly contributed by Hf). When this ratio is below 0.2, it means that the solute dragging effect at the grain boundaries is too weak relative to intragranular strengthening. At high temperatures, grain boundary migration and grain coarsening will become the main failure paths, thus rendering intragranular strengthening ineffective. When this ratio is above 1.5, it means that the concentration of solute atoms (especially rare earth elements) at the grain boundaries is too high relative to the concentration of strengthening components, leading to continuous grain boundary brittleness. The risk of phase transition is that an excessively strong grain boundary dragging effect can also hinder the formation of favorable textures during recrystallization, thus affecting the overall mechanical properties of the material. Therefore, controlling this ratio within this range is to achieve a balance and complementarity between the two stabilizing mechanisms. To ensure the stable reproduction of the above-mentioned complex microstructure in industrial production, this scheme introduces 0.01% to 0.05% by weight of scandium (Sc) and 0.005% to 0.02% by weight of tin (Sn) to introduce a self-regulating function into the phase transformation kinetics of the final product annealing process. Among them, scandium plays a crucial role in annealing. The heating stage precedes the formation of zirconium trialuminate nanophases, which serve as effective heterogeneous nucleation cores for zirconium trialuminate nanophases, reducing their nucleation energy barrier and promoting their rapid and uniform precipitation. During the annealing holding stage, when rare earth elements such as lanthanum and ytterbium segregate to a certain extent at the grain boundaries, the surface-active element tin will also spontaneously migrate to the grain boundaries. The presence of tin changes the interfacial energy of the grain boundaries and hinders the arrival of subsequent rare earth atoms, providing a self-terminating effect for the enrichment process of grain boundary elements and avoiding brittleness caused by excessive segregation of rare earth elements due to process fluctuations.

[0034] The present invention discloses a method for preparing bonding aluminum wire for integrated circuit packaging, comprising the following steps: providing an aluminum alloy ingot having any of the aforementioned components, wherein the alloy ingot uses aluminum with a purity of not less than 99.99% as the base material, and is melted by vacuum induction melting, with alloying elements added in descending order of melting point under an inert atmosphere, and then cast into an ingot after electromagnetic stirring; drawing the aluminum alloy ingot to form a semi-finished aluminum wire, the process including multiple drawing passes, with a cumulative true strain of not less than 3.0, to store sufficient deformation energy inside the wire; and performing a final annealing treatment on the semi-finished aluminum wire to obtain finished bonding aluminum wire, wherein the process parameters of the annealing treatment are: heating rate 0.5℃ / s to At a temperature of 5℃ / s, a holding temperature of 150℃ to 250℃, and a holding time of 1 minute to 30 minutes, the evolution of the aforementioned microstructures is controlled according to a preset path, resulting in bonded aluminum wires with a diameter of 10 to 50 micrometers and a room temperature resistivity not exceeding 2.95 μΩ·cm. Before wire drawing, to ensure a uniform and controllable microstructure precursor for subsequent phase transformation precipitation kinetics, the provided aluminum alloy ingot needs to undergo homogenization annealing. The key process parameters are determined by the following engineering calibration procedure: First, multiple samples are cut from the same ingot and an annealing process matrix is ​​constructed, with a temperature gradient set to 480°C. The annealing temperatures were set at 500℃, 520℃, and holding times of 8 hours, 12 hours, and 16 hours, respectively. Next, metallographic and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses were performed on the annealed samples to quantify two core indicators: the residual primary phase area fraction (A_residual) and the standard deviation of the concentration of key solute elements in the matrix (σ_c). Finally, the temperature and time combination that minimized A_residual to below 0.1% and minimized σ_c was selected as the homogenization annealing process parameters for subsequent mass production. This procedure transforms the as-cast structure into a supersaturated solid solution with uniform solute distribution, facilitating dislocation storage and... The dispersed precipitation during final annealing provides the necessary initial conditions. Furthermore, in the industrial production of finished filaments, a set of calibration procedures linking macroscopic physical properties and microstructural characteristics was established for process control and quality verification of the microstructural parameters defined in the claims. First, a set of standard samples was prepared through systematic annealing process experiments, and these samples were simultaneously subjected to transmission electron microscopy (TEM) analysis and macroscopic performance testing. TEM analysis was used to directly determine the average equivalent diameter d_p and number density N_v of the zirconium trialuminate nanophase, while the macroscopic performance testing measured its Vickers microhardness HV and residual resistivity ratio RRR = ρ_300K / ρ_4.2K; then, based on this batch of data, a process window in the HV-RRR two-dimensional parameter space is constructed. The boundary of this window is enclosed by sample data points where d_p ≤ 20 nm and N_v ≥ 1 x 10^21 per cubic meter. Finally, in subsequent production, only the HV and RRR values ​​of the finished filament need to be measured. If its coordinates fall within the preset process window, its microstructure is determined to meet the characteristics defined in the claims. This method directly links nanoscale structural constraints with rapidly measurable macroscopic performance indicators, providing a quantitative basis for the stable reproduction of the technology.

[0035] Example 1: In an accelerated thermal cycling aging test of a high-power silicon carbide power module for automotive applications, the module needs to withstand tens of thousands of power cycles within a temperature range of -40 to 200 degrees Celsius. This condition places demands on the thermomechanical fatigue resistance of the heat-affected zone at the root of the bonding wire solder joints. In the control group module using Al-1%Si alloy bonding wire, the resistivity of some solder joints began to rise continuously after about 15,000 cycles. Failure analysis showed that the failure was caused by grain coarsening of the aluminum matrix at the root of the solder joints under repeated high-temperature stress, while the silicon phase particles used for reinforcement aggregated and grew, which together led to the deterioration of the mechanical properties of this area, and finally fatigue microcracks initiated at the stress concentration point.

[0036] Under the same experimental conditions, in the experimental module of bonded aluminum wire prepared by the method of this invention, during the ultrasonic bonding stage of encapsulation, gallium atoms dissolved in the alloy composition segregated towards the newly formed defect region at the neck of the solder joint under the action of ultrasonic energy. This locally promoted atomic rearrangement, passivating the microscopic damage and residual stress caused by plastic deformation, providing an initial interface with a low defect density for subsequent long-term service. Furthermore, during accelerated thermal cycling aging, the dual-region synergistic stabilization mechanism within the bonded aluminum wire began to function. Specifically, the zirconium trialuminate nanophase dispersed within the grains pinned dislocation movement, inhibiting high-temperature creep, while the lanthanum and ytterbium solute atoms segregated at the grain boundaries dynamically dragged grain boundary migration, inhibiting grain growth. It should be noted that the damage passivation effect of gallium atoms during the bonding stage is different from that of zirconium, lanthanum, and ytterbium during the service stage. The structural stabilization effects constitute a temporal synergistic relationship: the former eliminates the main source of fatigue crack initiation, providing a prerequisite for the latter to maintain the long-term stability of the matrix, while the latter ensures that the value of eliminating early defects is not weakened by the deterioration of the matrix itself. This technical approach does not follow the method of increasing the volume fraction of hard reinforcing phase to improve high-temperature strength, but instead constructs a microstructure that is insensitive to heat and stress while maintaining the conductivity of the aluminum matrix, thereby resolving the constraint relationship between the high-temperature strength and conductivity of the material. After undergoing a complete 30,000 temperature cycle shock, the resistivity change rate of all its solder joint interfaces was lower than the preset failure threshold, and scanning electron microscopy showed no signs of microcrack initiation at the root of the solder joints, and the micrograin size did not change significantly compared with the initial state.

[0037] Example 2: To objectively verify the mechanical property stability of the bonded aluminum wire prepared by the method of the present invention at high temperature, and to elucidate the synergistic effect among its core alloying components, a comparative performance test was conducted in this example. Four sample groups were set up: control group 1, which was a standard Al-1%Si alloy; control group 2, which had 0.1% Zr added alone to the Al-1%Si matrix; control group 3, which had 0.06% La and Yb (weight ratio 1:1) added alone to the Al-1%Si matrix; and the experimental group, which was a sample prepared according to a specific embodiment of the present invention, whose core alloying components, by weight percentage, included: 1.0% Si, 0.10% Zr, 0.06% La and Yb (weight ratio 1:1), 0.05% Hf, 0.03% Ga, 0.3% Cu, 0.03% Sc, and 0.01% Sn. The balance was Al with a purity of not less than 99.99%. All samples were prepared using the same process: vacuum induction melting, ingot casting, wire drawing with a cumulative true strain of 4.0, and finally annealing at 200℃ for 15 minutes to obtain finished wires with a diameter of 25 micrometers. The test process included uniaxial tensile tests at room temperature (25℃) and high temperature (200℃), as well as resistivity tests at room temperature. The tensile test was conducted on a universal testing machine equipped with a high-temperature environmental chamber with a temperature control accuracy of ±1℃. Before high-temperature tensile testing, the samples were kept at 200℃ for 30 minutes to ensure that the internal temperature of the material reached equilibrium. The resistivity test used the four-point probe method on a test platform with a current source accuracy of ±0.05% and a voltmeter resolution of 10nV. All tests were completed under the same equipment and environmental conditions in the same batch to eliminate interference from irrelevant variables.

[0038] The experimental results showed that the tensile strength of all sample groups at room temperature was within the range of 185 MPa to 193 MPa, with no significant difference. However, at 200℃, the performance diverged significantly. The strength of control group 1 decreased to 81.5 MPa, with a strength retention rate of only 44.0%. The high-temperature strengths of control groups 2 and 3 increased to 103.0 MPa and 96.2 MPa, respectively, with corresponding strength retention rates of 54.2% and 51.0%, showing the limited improvement effect of a single strengthening mechanism. In contrast, the experimental group still exhibited a tensile strength of 158.8 MPa at 200℃, with a strength retention rate of 82.5%, which was much higher than the sum of the performance improvements of control groups 2 and 3. At the same time, the room temperature resistivity of the experimental group was 2.94 μΩ·cm, compared with 2.91 μΩ·cm of the control group. The result of 93 μΩ·cm is at the same level, indicating that the performance improvement did not come at the cost of deteriorated conductivity. The data shows that although adding Zr alone (control group 2) or La and Yb (control group 3) can improve the high-temperature strength to a certain extent through intragranular pinning and grain boundary dragging, when grain boundary migration and intragranular dislocation movement are simultaneously suppressed by the aforementioned dual-zone synergistic stabilization mechanism (experimental group), the overall high-temperature stability of the material exhibits a nonlinear enhancement effect. The reason is that when only grain boundary stabilization is achieved, intragranular softening still occurs, and when only intragranular strengthening is achieved, grain coarsening caused by grain boundary migration becomes a performance bottleneck. The experimental results confirm that the bonded aluminum wire obtained by combining the chemical composition design and preparation process of this invention has complementary functions of different elemental components in its microstructure, thereby improving its high-temperature strength without deteriorating the conductivity of the material (see Table 1).

[0039] Table 1: Comparison of mechanical and electrical properties of different alloy samples at room temperature and high temperature.

[0040] Sample group name Core alloy composition Room temperature tensile strength (25℃, MPa) High temperature tensile strength (200℃, MPa) Strength retention rate (%) Room temperature resistivity (μΩ·cm) Control group 1 Al-1%Si 185.2 81.5 44.0 2.91-2.93 Control group 2 Al-1%Si+0.1%Zr 190.0 103.0 54.2 2.91-2.93 Control group 3 Al-1%Si+0.06%La / Yb 188.6 96.2 51.0 2.91-2.93 Test group of the present invention Al-Si-Zr-La-Yb-Ga-Cu-Hf-Sc-Sn 192.5 158.8 82.5 2.94

[0041] To further verify the reliability of the test group samples under electrothermal coupling conditions, this embodiment supplemented an accelerated electromigration lifetime test under high temperature and high current density. Control group 1 (Al-1%Si) and the test group of this invention (containing 0.05% Hf by weight) wire samples were placed in a test chamber with a constant ambient temperature of 200°C. A DC current density of 500,000 amperes per square centimeter was applied, and the resistance change of the samples was continuously monitored. A 20% increase in resistance was used as the failure criterion. The test results showed that the median time to failure (MTTF) of the control group 1 sample was 520 hours, while the median time to failure of the test group sample reached 1580 hours. This data indicates that the composite addition of zirconium, lanthanum, ytterbium, and hafnium to the alloy can suppress atomic migration of the material under high temperature and high current density, thereby improving its anti-electromigration performance.

[0042] Example 3: This example combines Figure 1 to Figure 4 This document describes a bonding aluminum wire for integrated circuit packaging and its preparation method, as follows: Figure 1 As shown, the functional elements in the alloy are divided into three logical groups. The first group is the high-temperature structural stabilization group, which is responsible for providing high-temperature structural stability. This group includes zirconium (Zr), lanthanum (La), ytterbium (Yb), and hafnium (Hf). This group of elements hinders dislocation movement by forming zirconium trialuminate nanophases coherent with the matrix inside the grains, and inhibits grain growth by achieving the segregation of solute atoms such as La, Yb, and Hf at the grain boundaries. The two mechanisms work synergistically to ultimately improve high-temperature strength and fatigue resistance. The second group is the damage repair and healing group, which is responsible for damage repair and healing. This group includes gallium (Ga) and copper (Cu). Among them, Ga atoms can be repaired and healed by ultrasound. Segregation towards defect areas promotes stress relaxation and achieves self-passivation of bonding damage. The Al-Si-Cu eutectic structure can melt instantaneously under thermal shock, fill microcracks and rebuild the strengthening phase, achieving thermal shock self-healing. Together, they enhance the service reliability of the bonding wire throughout its entire life cycle. The third group is the manufacturing process optimization group, which is responsible for optimizing the manufacturing process. It includes scandium (Sc) and tin (Sn). The scandium trialuminate phase can serve as a heterogeneous nucleation core for zirconium trialuminate, achieving nucleation catalysis of the strengthening phase. Meanwhile, the Sn-wetting grain boundaries provide a self-termination effect for the enrichment of rare earth elements, avoiding embrittlement. Together, they broaden the consistency of finished product performance and the process window.

[0043] like Figure 2 As shown in the figure, the horizontal axis represents the Cu content (wt%), the left vertical axis represents the strength recovery rate (%), and the right vertical axis represents the resistivity degradation rate. The solid line marked with circles in the figure shows that when the Cu content increases from 0.1% to 0.3%, the strength recovery rate increases from 75% to 95%, and remains at 95% as the Cu content continues to increase. The dashed line marked with triangles shows that the resistivity degradation rate continuously increases with the Cu content. After the Cu content exceeds 0.3%, the rate of increase becomes steeper. This indicates that to maximize the self-healing effect while keeping the impact on conductivity at a low level, the preferred Cu content range should be between 0.2% and 0.3%.

[0044] like Figure 3 As shown, inside grain 1, zirconium trialuminate nanophases, represented by black dots, are dispersed. At the grain boundaries between grains, there are solute atom segregation regions represented by black squares (La, Yb, Hf, Sn, etc.) and Al-Si-Cu ternary eutectic structure represented by black triangles. The 20nm scale bar in the figure intuitively reflects the nanoscale characteristics of this microstructure.

[0045] like Figure 4As shown, within the grains, there are dispersed zirconium trialuminate nanophases with a size no greater than 20 nm and a number density no less than one x ten to the power of twenty-first per cubic meter. At the grain boundaries, there are La / Yb atom segregations in the weight ratio range of 1:3 to 3:1, and an Al-Si-Cu ternary eutectic structure with a melting point of 520℃ to 550℃. In the aluminum matrix, there are Ga atoms dissolved in solid solution at a content of 0.005% to 0.05%. The schematic diagram also shows the weight percentage content of the main components, including 0.5% to 1.2% Si, 0.05% to 0.15% Zr, and 0.1% to 0.5% Cu, and lists optional added elements and their content ranges, including 0.01% to 0.1% Hf, 0.01% to 0.05% Sc, and 0.005% to 0.02% Sn.

[0046] Example 4: This example provides an engineering calibration procedure for determining the preferred addition amount of copper (Cu) in a specific application scenario to form a microstructure self-healing mechanism in bonded aluminum wires. In the design of an aerospace-grade power conversion module, when the silicon carbide device is subjected to transient overcurrent, the bonding wire connection point may experience a thermal shock from the normal operating temperature of 200°C to over 550°C within hundreds of milliseconds. The design requires that the mechanical and electrical properties of the connection point can still recover to more than 90% of the initial state after such thermal shock. In view of this, it is necessary to calibrate the content of copper component in the alloy of the present invention within the range of 0.1% to 0.5% by weight to find a window that balances the self-healing effect and the electrical properties of the substrate.

[0047] To determine the preferred content, this embodiment employs a gradient experiment. First, using the remaining components of the experimental group of this invention as a base, five alloy ingots were prepared by vacuum induction melting, with the copper weight percentage content set as a gradient series: 0.1%, 0.2%, 0.3%, 0.4%, and 0.5%. All alloy ingots underwent identical post-processing, namely wire drawing with a cumulative true strain of 4.0 and finished product annealing at 200°C for 15 minutes, ultimately producing bonded aluminum wire samples with a diameter of 30 micrometers. Subsequently, all samples underwent a damage-healing cycle test, which included three steps: the first step employed a four-point probe method and The first step involved micro-tensile testing, measuring and recording the initial resistivity R_0 and initial tensile strength S_0 of each group of samples at 25℃. The second step involved placing the samples in a test stage that could achieve Joule heating via a large current pulse, applying a 500ms current pulse with a pre-calibrated amplitude that allowed the wire temperature to reach a peak of 560℃±5℃ within 200ms, thereby triggering a self-healing mechanism driven by the instantaneous melting of the Al-Si-Cu ternary hypoeutectic structure. The third step involved cooling the samples to room temperature in air, then measuring their final resistivity R_f and final tensile strength S_f using the same method.

[0048] By comparing the performance parameters before and after the test, the self-healing effect under different copper contents can be quantitatively evaluated. When the copper content is 0.1%, the strength recovery rate (S_f / S_0) of the sample is 75%, because the instantaneous liquid phase volume formed at this content is insufficient to completely fill the microscopic damage caused by thermal shock stress. When the copper content increases to 0.2% and 0.3%, the strength recovery rate rises to 92% and 95% respectively, and the resistivity degradation rate ((R_f-R_0) / R_0) is less than 2%, indicating that the material structure is restored after thermal shock. When the copper content is further increased... At 0.4% and 0.5%, although the strength recovery rate remained at 95%, the initial resistivity R_0 increased compared to the low content group, and the resistivity degradation rate after thermal shock also increased. This is because excessive copper forms more intermetallic compounds at the grain boundaries, increasing electron scattering. Through this calibration procedure, for the performance recovery rate requirements of this specific application scenario, the preferred range of copper content can be determined to be 0.2% to 0.3% by weight. The composition configuration within this range can provide self-healing capability while having a small impact on the material's conductivity, as shown in Table 2.

[0049] Table 2: Effect of different Cu contents on the strength recovery rate and resistivity degradation rate of alloys after thermal shock.

[0050] Copper content (wt%) Strength recovery rate (S_f / S0, %) resistivity deterioration rate ((R_f - R0) / R0, %) Performance evaluation and mechanism analysis 0.1 75 Not mentioned The volume of transient liquid phase is not enough to completely fill the micro-damage caused by thermal shock. 0.2 92 <2 The material structure is restored, the influence on electrical conductivity is small, and it is within the preferred range. 0.3 95 <2 The strength recovery rate is maximized, the influence on electrical conductivity is small, and it is within the preferred range. 0.4 95 Increased Although the strength recovery rate remains at a high level, excessive copper forms intermetallic compounds at the grain boundaries, increasing electron scattering, leading to deterioration of electrical conductivity. 0.5 95 Increased As above.

[0051] Example 5: This example provides a pre-calibration procedure for determining the optimal process parameters for different production batches or product specifications in the final annealing process. When building a new production line for bonding aluminum wire with a diameter of 15 micrometers to meet specific high-density packaging requirements, in order to converge the process window of holding temperature from 150°C to 250°C and holding time from 1 minute to 30 minutes to an optimal process point for that specific wire diameter, the following procedure needs to be performed: First, take 15-micrometer aluminum wire semi-finished products from the same batch after drawing and prepare a 3x3 annealing process. The process matrix sample group had a temperature gradient of 180℃, 200℃, and 220℃, with a holding time gradient of 5 minutes, 10 minutes, and 15 minutes for each temperature gradient. Subsequently, the nine sample groups were annealed under the corresponding process parameters. Two performance indicators were tested on each sample group after treatment: microhardness was measured by Vickers hardness tester to characterize the precipitation strengthening degree of intracrystalline zirconium trialuminate nanophase, and elongation at break was measured by uniaxial tensile test to characterize the influence of grain boundary state on the toughness of the material.

[0052] Analysis of the above test data reveals the optimal process parameters. In this calibration test, the microhardness of the sample reached its peak when the annealing parameters were 200℃ and 10 minutes, indicating that the precipitation strengthening effect of the zirconium trialuminate nanophase was sufficient. If the holding time was extended to 15 minutes or the temperature was increased to 220℃, the hardness value did not increase further. Meanwhile, the elongation at break data showed that at the parameter point of 200℃ and 10 minutes, the elongation remained at a high level. However, when the holding time was extended to 15 minutes or the temperature was increased to 220℃, the elongation showed a decreasing trend. This is related to the embrittlement that may be caused by excessive segregation of rare earth elements at the grain boundaries. Therefore, considering the balance between hardness and toughness, the calibration procedure ultimately determined 200℃ and 10 minutes as the optimal annealing process parameters for the production of this 15-micron wire. This procedure can be applied to the pre-production calibration of different batches of raw materials or different product specifications to ensure the stability and reproducibility of the final finished wire performance, as shown in Table 3.

[0053] Table 3: Experimental data table of optimization matrix for annealing process parameters of 15-micron aluminum wire semi-finished product and final finished product.

[0054] Soaking temperature (℃) Soaking time (minutes) Microhardness (HV) Elongation at break (%) 180 5 55.2 8.5 180 10 58.1 8.2 180 15 58.9 7.9 200 5 60.5 8.1 200 10 62.3 (peak) 8.0 (higher level) 200 15 62.1 7.2 (decrease) 220 5 61.8 7.5 (decrease) 220 10 61.5 6.8 (significant decrease) 220 15 60.2 6.1 (significant decrease)

[0055] Example 6: This example provides an engineering procedure for optimizing the ultrasonic bonding process window in a specific packaging application of the aforementioned gallium (Ga)-containing aluminum bonding wire. When performing wire bonding on a chip using a low-k material as the underlying insulating medium, in order to form a reliable connection while reducing mechanical damage to the structure below the chip pads, the bonding process parameters need to be calibrated. This procedure aims to determine an optimal process window that can utilize a gallium atom-assisted stress relaxation mechanism, thereby achieving a high-reliability connection with lower energy input. The procedure first prepares a bonding process matrix sample set, fixes the bonding pressure and time, uses ultrasonic power as a variable, sets three gradient levels of 80mW, 100mW, and 120mW, and performs solder joint preparation under these three sets of parameters.

[0056] To assess bonding quality, the procedure employs a dual quantitative index system. The first is the solder joint pull force obtained through a standard wire drawing test, which must exceed a minimum threshold of 8 gf. The second is the average nuclear mean mass difference (KAM) measured by electron backscatter diffraction (EBSD) on a cross-sectional slice of the solder joint neck region. This value quantitatively characterizes the residual strain and microdefect density in this region, thus reflecting the completeness of the gallium atom self-healing mechanism. Test results show that at 80 mW power, the solder joint pull force is near the minimum threshold, but its average KAM value is relatively high, indicating large internal residual strain. At 00mW power, the solder joint pull force is relatively high, and the average KAM value reaches its lowest level, indicating that this power level is sufficient to activate gallium atom migration and stress relaxation, forming a connection interface with both high strength and low defects. When the power is increased to 120mW, although the pull force and KAM value remain at the expected level, a slight crater effect has been observed on some solder pads. Based on this, the procedure determines 100mW as the preferred bonding power for this specific application scenario. This method links a microscopic material mechanism with a quantifiable macroscopic process window calibration process, thereby providing a process basis for the reproducible deployment of the alloy of this invention in different applications.

[0057] Example 7: To clarify the technical basis for the content range of key components in the alloy of the present invention and to verify the synergistic technical effect among the components, this example experiment was conducted. This experiment aims to determine the technical trade-off basis for the weight percentage content range of zirconium (Zr) (0.05% to 0.15%). The experiment was based on an alloy containing 1.0% Si, 0.06% La, 0.06% Yb, 0.03% Ga, 0.3% Cu and the balance Al. Three groups of samples with zirconium contents of 0.03% (below the lower limit), 0.10% (within the range), and 0.20% (above the upper limit) were prepared. All samples underwent wire drawing with a cumulative true strain of 4.0 and were annealed at 200°C for 15 minutes to produce wires with a diameter of 25 micrometers. The test results show that when the zirconium content is 0.03%, its tensile strength retention rate at 200°C is less than 55%. Metallographic analysis showed that the volume fraction and number density of the zirconium trialuminate nanophase formed at this content were insufficient, failing to effectively pin dislocation movement within the grains, leading to softening of the matrix at high temperatures. When the zirconium content was 0.20%, its room temperature resistivity increased by more than 3% compared to the sample with 0.10% content. Metallographic analysis showed that excessive zirconium caused some zirconium trialuminate precipitates to coarsen and tend to transform into incoherent phases, increasing the scattering of conduction electrons. At the same time, its high-temperature strength retention rate did not further improve compared to the sample with 0.10% content. When the zirconium content was 0.10%, the sample retained more than 80% of its tensile strength at 200℃, and the room temperature resistivity remained at the level of 2.94 μΩ·cm. This content range enables the formation of size-dispersed, high-number-density coherent zirconium trialuminate nanophases in the aluminum matrix, providing high-temperature strengthening while keeping the impact on the material's electrical conductivity within an acceptable range. The experimental data indicate that a zirconium content range of 0.05% to 0.15% is the technical window determined to balance the high-temperature mechanical and electrical properties of the material.

[0058] The performance of the technical solution of this invention is determined by a specific formula-process-structure chain. Specifically, an alloy formula containing 0.05%-0.15% Zr, 0.01%-0.08% La, and Yb, after being drawn with a cumulative true strain of not less than 3.0, stores deformation energy within the wire to drive recrystallization and phase transformation precipitation. Subsequently, under the final annealing process at 150°C to 250°C, the preset chemical composition and thermodynamic conditions jointly promote the formation of a dual-zone synergistic microstructure: within the grains, coherent zirconium trialuminate nanophases with an average equivalent diameter of not more than 20 nanometers are dispersedly precipitated; at the grain boundaries, solute atoms such as La and Yb segregate. It is this microstructure, determined by a specific formula and a specific process, that achieves stabilization both within the grains and at the grain boundaries, that ultimately enables the finished bonded aluminum wire to achieve a tensile strength retention rate of more than 70% at room temperature in an environment of 200°C.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bonding aluminum wire for integrated circuit packaging, the bonding aluminum wire being made of an aluminum alloy, characterized in that, The aluminum alloy is composed of the following components by weight percentage: aluminum as the matrix and 0.5% to 1.2% silicon; Zirconium content ranging from 0.05% to 0.15%; The total content is 0.01% to 0.08% lanthanum and ytterbium; 0.005% to 0.05% gallium; and 0.1% to 0.5% copper; In aluminum alloys, the weight ratio of lanthanum to ytterbium is in the range of 1:3 to 3:1, and the ratio of the total weight of lanthanum and ytterbium to the weight of zirconium is in the range of 0.1 to 1.

0. In the microstructure of aluminum alloy, the zirconium trialuminate nanophase, which is coherent with the aluminum matrix, is dispersed inside the aluminum matrix grains. The average equivalent diameter of the zirconium trialuminate nanophase is no more than 20 nanometers, and the number density is no less than one to the power of 10 to the power of 21 per cubic meter. At the grain boundaries of the aluminum matrix, solute atoms of lanthanum and ytterbium are segregated; gallium exists in the lattice of the aluminum matrix in the form of solid solution atoms; copper, aluminum matrix and silicon together form an Al-Si-Cu ternary low eutectic structure at the grain boundaries of the aluminum matrix. The melting point of the Al-Si-Cu ternary low eutectic structure is in the range of 520℃ to 550℃. The Al-Si-Cu ternary low eutectic structure is discontinuously distributed in the microstructure of the aluminum alloy, and the Al-Si-Cu ternary low eutectic structure and zirconium trialuminate nanophase have a lattice mismatch of less than 5% required for heterogeneous nucleation.

2. The bonding aluminum wire for integrated circuit packaging according to claim 1, characterized in that, The aluminum alloy also contains 0.01% to 0.1% by weight of hafnium, which, along with lanthanum and ytterbium, segregates at the grain boundaries of the aluminum matrix and forms localized chemical bonds with the surrounding aluminum atoms.

3. The bonding aluminum wire for integrated circuit packaging according to claim 2, characterized in that, In aluminum alloys, the ratio of the sum of the weight percentage concentrations of lanthanum and ytterbium to the sum of the weight percentage concentrations of zirconium and hafnium satisfies the constraint defined by the following relationship: 0.2≤(C_La+C_Yb) / (C_Zr+C_Hf)≤1.5; where C_La is the weight percentage concentration of lanthanum, C_Yb is the weight percentage concentration of ytterbium, C_Zr is the weight percentage concentration of zirconium, and C_Hf is the weight percentage concentration of hafnium.

4. The bonding aluminum wire for integrated circuit packaging according to claim 1, characterized in that, The aluminum alloy also contains 0.01% to 0.05% by weight of scandium and 0.005% to 0.02% by weight of tin; in the microstructure of the aluminum alloy, scandium partially forms scandium trialuminate phase as a heterogeneous nucleation core for zirconium trialuminate nanophase; in the microstructure of the aluminum alloy, tin is enriched at the grain boundaries of the aluminum matrix.

5. The bonding aluminum wire for integrated circuit packaging according to claim 4, characterized in that, The aluminum alloy obtains its microstructure after undergoing a final annealing process. The parameters of the final annealing process are: heating rate of 0.5℃ / s to 5℃ / s, holding temperature of 150℃ to 250℃, and holding time of 1 minute to 30 minutes.

6. The bonding aluminum wire for integrated circuit packaging according to claim 1, characterized in that, The room temperature resistivity of the bonded aluminum wire is no higher than 2.95 μΩ·cm.

7. The bonding aluminum wire for integrated circuit packaging according to claim 1, characterized in that, The tensile strength of bonded aluminum wire measured at 200°C is more than 70% of the tensile strength measured at room temperature.

8. The bonding aluminum wire for integrated circuit packaging according to claim 1, characterized in that, The finished diameter of the bonded aluminum wire ranges from 10 micrometers to 50 micrometers.

9. A method for preparing bonding aluminum wire for integrated circuit packaging, characterized in that, The methods include: An aluminum alloy ingot is provided, which is composed of the aluminum alloy of claim 1; The aluminum alloy ingot is drawn into a wire to form a semi-finished aluminum wire. The cumulative true strain of the drawing process is not less than 3.

0. The aluminum wire semi-finished product is subjected to final annealing treatment to obtain bonded aluminum wire; the process parameters for the final annealing treatment are: heating rate of 0.5℃ / s to 5℃ / s, holding temperature of 150℃ to 250℃, and holding time of 1 minute to 30 minutes.

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