Silver-gold-platinum-palladium-copper-rhenium alloy and preparation method and application thereof

Abstract

The invention discloses a silver-gold-platinum-palladium-copper-rhenium alloy and a preparation method and application thereof, and belongs to the technical field of precise materials for semiconductor detection. The alloy comprises the following components in percentage by mass: 20%-25% of Au, 8%-12% of Pt, 5%-8% of Pd, 3%-5% of Cu, 0.3%-0.8% of Re and the balance of Ag. According to the preparation method, an Ag-Au infinite solid solution is used as a matrix, a Pd-Cu composite strengthening system and a Re microalloying regulation and control technology are introduced, so that Pd and Pt form a continuous solid solution, the high-temperature stability is improved, and Re refines grains to 5-8 microns through a grain boundary segregation effect; according to the method, vacuum-atmosphere alternate smelting is combined with multi-field synergistic aging, a nano-scale to micron-scale second phase is induced to be uniformly separated out, the synergistic effect of dislocation strengthening and second phase strengthening is achieved, frictional wear in the plugging and unplugging process is resisted through surface strengthening, and the conductivity of the alloy is not affected. Finally, the hardness of the probe material reaches 430-450 HV, the resistivity reaches 4 * 10 <-8 > omegam or below, the plugging service life reaches 30,000-50,000 times, and the probe material has excellent comprehensive performance and is suitable for high-precision detection scenes of chips.

Description

Technical Field

[0001] This invention belongs to the field of precision materials technology for semiconductor testing, and relates to a silver-gold-platinum-palladium-copper-rhenium alloy, its preparation method and application. Background Technology

[0002] With the continuous development of chip technology, testing frequencies have increased to over 10GHz, placing more stringent performance requirements on chip test probes. These requirements primarily include three core performance characteristics: high hardness, low resistivity, and long lifespan during frequent insertion and removal. Test probes used for chip testing typically need a hardness of 400HV or higher to withstand the enormous stress generated during high-frequency insertion and removal when the probe contacts the chip pads, preventing plastic deformation and ensuring accurate contact with the designated location in every test. Lower resistivity ensures that the high-frequency test signal does not experience significant attenuation or delay during transmission, guaranteeing signal integrity. Furthermore, increasing the probe's long lifespan during frequent insertion and removal reduces testing costs and improves testing efficiency.

[0003] Currently, most chip test probe materials utilize Pd-based high-hardness alloy systems, with typical examples including the Paliney series alloys and the TK probe series alloys produced by TANAKA. While these alloys meet basic hardness requirements, their electrical conductivity is relatively low. For instance, the Paliney7 alloy (composed of 35wt%Pd-10wt%Au-10wt%Pt-30wt%Ag-14wt%Cu-1wt%Zn), despite its superior overall performance, only achieves a conductivity of 5.5% IACS, indicating a high resistivity that makes it unsuitable for high-frequency, high-current testing scenarios. As chip manufacturing processes advance to 3-5nm and below, and test signal frequencies increase to over 10GHz, the signal attenuation and probe overheating issues caused by low conductivity (high resistivity) become increasingly prominent, severely impacting test accuracy and probe lifespan.

[0004] Meanwhile, existing Pd-based alloys have shortcomings in controlling the distribution of the nanoscale second phase. For example, patent application number CN202111008644.1 discloses a palladium-copper-silver-ruthenium alloy. Although it achieves grain refinement by adding ruthenium, its second phase size fluctuates within a wide range, resulting in poor uniformity of material mechanical properties. It is prone to brittle fracture during insertion and extraction, reducing its service life. Furthermore, its hardness is at most 429 HV, at which point the alloy conductivity is 23% IACS. Although this represents a certain improvement in overall performance compared to traditional Paliney series alloys, the overall performance of chip detection probe alloys can be further improved to extend probe life and reduce testing costs.

[0005] Currently, Ag-based alloys are still used as the material for chip test probes. Although Ag-based alloys have high conductivity, their hardness is generally lower than 300 HV and their wear resistance is poor, making it difficult to meet the mechanical performance requirements of probes.

[0006] Therefore, it is necessary to provide a silver-gold-platinum-palladium-copper-rhenium alloy, its preparation method, and its application, which can effectively ensure that the alloy has high hardness and high lifespan during frequent insertion and removal, while maintaining low resistivity. This ensures that chip test probes can maintain excellent test accuracy, integrity, and lifespan in advanced process chip testing scenarios, while effectively reducing test costs. Summary of the Invention

[0007] To overcome the problems in the prior art, this invention optimizes the alloy composition and preparation method to synergistically improve the alloy's hardness and conductivity, thereby obtaining an alloy with superior overall performance to meet the stringent performance requirements of chip test probes.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: The present invention proposes a silver-gold-platinum-palladium-copper-rhenium alloy, wherein the alloy composition by mass percentage includes: Au: 20%~25%, Pt: 8%~12%, Pd: 5%~8%, Cu: 3%~5%, Re: 0.3%~0.8%, with the balance being Ag.

[0009] Preferably, the alloy composition, by mass percentage, includes: Au: 22%~24%, Pt: 9%~11%, Pd: 6%~7%, Cu: 3.5%~4.5%, Re: 0.5%~0.7%, with the balance being Ag.

[0010] In another aspect, the present invention provides a method for preparing the above-mentioned alloy, the method comprising the following steps: (1) Raw material pretreatment: Weigh Ag, Au, Pt, Pd, Cu and Re raw materials according to the alloy mass percentage, and then perform surface cleaning treatment on the raw materials. If the raw materials after surface cleaning need to be stored, place the raw materials in an argon environment with a dew point ≤ -40℃, for example, store the raw materials in an argon glove box, and the storage time should generally not exceed 72h.

[0011] The purity of the raw material metals is not less than 99.99%.

[0012] (2) Vacuum-atmosphere alternating melting: The Ag, Au, Pt and Pd raw materials after surface purification treatment in step (1) are subjected to vacuum induction melting. After the raw materials are melted, the temperature is kept constant and inert gas is introduced. Preheated Cu and Re raw materials are added to continue melting. Then the vacuuming and inert gas introduction operations are repeated twice to obtain the alloy melt.

[0013] (3) Directional solidification casting: The alloy melt obtained in step (2) is cast and directional solidification is carried out by controlling the alloy melt to generate a gradually increasing temperature gradient from bottom to top to obtain an alloy ingot.

[0014] (4) Multi-pass plastic processing: The alloy ingot obtained in step (3) is subjected to hot rolling and multi-pass cold drawing to obtain alloy wire, wherein vacuum intermediate annealing is performed after every 3 passes of cold drawing.

[0015] (5) Multi-field synergistic aging: Under DC magnetic field and vacuum conditions, the alloy wire obtained in step (4) is subjected to step aging treatment. Then, when the alloy wire is cooled to below 100°C in the furnace, argon gas is introduced to allow the alloy wire to continue cooling to room temperature in the furnace, thus obtaining silver-gold-platinum-palladium-copper-rhenium alloy wire.

[0016] Preferably, in step (1), the specific method of surface purification treatment includes: Ag and Cu raw materials are ultrasonically cleaned with dilute sulfuric acid; Au, Pt, and Pd raw materials are soaked at room temperature with a mixture of nitric acid and hydrofluoric acid; Re raw materials are ultrasonically treated with citric acid solution, and then all raw materials are rinsed and vacuum dried in sequence to complete the surface purification treatment.

[0017] Preferably, the concentration of the dilute sulfuric acid is 10%, the ultrasonic cleaning time for Ag and Cu raw materials is 5 minutes, and the frequency is 25-30 kHz; the concentration of the nitric acid is 5%, the concentration of the hydrofluoric acid is 1%, and the volume ratio of nitric acid to hydrofluoric acid in the mixed solution is nitric acid:hydrofluoric acid = 4:1; the soaking time for Au, Pt, and Pd raw materials at room temperature is 3 minutes; the concentration of the citric acid solution is 15%, the ultrasonic treatment time for Re raw materials is 8 minutes, and the frequency is 20-25 kHz; all raw materials are rinsed with deionized water; the vacuum drying temperature is 100°C, and the vacuum drying time is 1 hour.

[0018] Preferably, in step (2), the vacuum degree during vacuum induction melting is ≤5×10⁻⁶. -4 The melting temperature is 1450~1500℃, and the melting time of Ag, Au, Pt, and Pd raw materials is 25~30min. Inert gas is introduced to 0.08MPa, and after adding Cu and Re, the melting time continues for 15~20min. This process is then repeated until the vacuum level is ≤5×10⁻⁶. -4 The pressure is maintained at 0.05-0.08 MPa for 8-10 minutes, and then inert gas is introduced to maintain the pressure at 0.05-0.08 MPa for 3-5 minutes. This process is repeated twice. The inert gas is high-purity argon (99.99% purity). The melt is continuously stirred at a speed of 20-30 r / min throughout the vacuum induction melting process.

[0019] Preferably, the preheating temperature of Cu and Re is 500°C.

[0020] Preferably, in step (3), the mold used for casting is preheated to 400~450℃, the temperature of the alloy melt is 1350~1400℃ during casting, the casting speed is 15~25ml / s, and the temperature gradient of directional solidification is increased from bottom to top at 8~10℃ / cm. After complete solidification, a cylindrical ingot with a diameter of 15~20mm is obtained.

[0021] Preferably, in step (4), the hot rolling temperature is 800~850℃, the single-pass reduction is 15%~18%, the hot rolling speed is 1m / min, and the alloy ingot is formed into a bar with a diameter of 5~10mm after hot rolling. Each set of three cold drawing passes constitutes a cold drawing process, wherein the deformation amounts of the three cold drawing passes are 18%, 15%, and 12% respectively, and the cold drawing speeds are 3m / min, 5m / min, and 8m / min respectively. Multiple sets of cold drawing processes are performed in a cycle to draw the bar into an alloy wire with a diameter of 0.5~1.5mm. The intermediate annealing temperature is 350~400℃, and the intermediate annealing time is 1~1.5h.

[0022] Preferably, in step (5), the DC magnetic field strength is 0.3T, and the specific process of the stage aging treatment is as follows: heat the alloy wire to 180~200℃, keep it at that temperature for 3 hours, and then raise the temperature to 260~280℃ and keep it at that temperature for 2 hours.

[0023] This invention also proposes the application of the above-mentioned alloy in the fabrication of chip test probes, wherein the method for fabricating the chip test probes includes the following steps: S1: A colloidal silica polishing slurry with a particle size of 50 nm and a pH of 7.5–8.5 was used to perform mechanochemical polishing on silver-gold-platinum-palladium-copper-rhenium alloy wires. During polishing, the polishing pressure was 0.03–0.05 MPa, the stirring speed was 20–30 r / min, and the mechanochemical polishing time was 10–15 min. This was done to remove residual burrs and micro-protrusions from the wire surface, reducing the surface roughness to below 0.03 μm.

[0024] S2: The filament material after mechanical and chemical polishing in step S1 is subjected to ion sputtering cleaning using argon gas, with a cleaning power of 150W and a cleaning time of 5-8 minutes. This is to remove trace amounts of oxide layer and oil stains from the surface of the filament material.

[0025] S3: Graphite is sputtered onto the surface of the filament to form a diamond-like carbon (DLC) coating. The sputtering temperature is ≤180℃, the sputtering power is 300W, and sputtering is stopped when the DLC coating thickness reaches 80~100nm. The filament is then subjected to vacuum insulation treatment to obtain the chip test probe. The vacuum insulation vacuum degree is 1×10⁻⁶. -3 The insulation temperature is 150~200℃, and the insulation time is 1~1.5h. Vacuum insulation treatment can release the internal stress of the coating.

[0026] The beneficial effects of this invention are: 1. This invention, by adding Au to form an infinitely miscible solid solution with Ag, not only significantly improves the oxidation resistance of the alloy, but also creates conditions for subsequent strengthening through alloying.

[0027] 2. This invention introduces a Pd-Cu composite strengthening system, in which Pd and Pt form a continuous solid solution, enhancing the high-temperature stability of the alloy, and Cu synergizes with Ag to optimize the conductive network structure.

[0028] 3. This invention introduces Re for microalloying, and through the grain boundary segregation effect of Re, significantly and stably refines the grains to 5-8 μm.

[0029] 4. This invention successfully induces uniformly distributed nanoscale PtCu2 precipitates by combining vacuum-atmosphere alternating melting with multi-field synergistic aging treatment, achieving synergistic enhancement of dislocation strengthening and second phase strengthening.

[0030] 5. This invention provides a fundamental guarantee for efficient transmission of electrical signals by selecting highly conductive Ag as the main matrix (the resistivity of pure silver in the room temperature annealed state is only 1.59µΩ∙cm, which is better than Au's 2.2µΩ∙cm).

[0031] 6. This invention can maintain the Vickers hardness of the alloy between 430 and 450 HV, and reduce the resistivity to 4 × 10⁻⁶ HV. -8 With a strength below Ω·m, it possesses excellent synergy between mechanical strength and electrical conductivity; after surface strengthening, the insertion and extraction life can reach 30,000 to 50,000 cycles, which can fully meet the performance requirements of chip detection probes for hardness, conductivity and service life, providing a reliable alloy substrate selection for mid-to-high-end chip detection probes.

[0032] 7. Pd, Pt, Ag, and Au are all precious metals. Currently, the unit price of these four metals in the market, from highest to lowest, is Pd, Au, Pt, and Ag. Furthermore, the unit price of Pd is significantly higher than that of Ag. Therefore, by selecting Ag as the matrix, this invention reduces the amount of Pd used, which helps to reduce the cost of alloy raw materials and thus the cost of alloy preparation. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0034] Figure 2 The metallographic structure of the alloy prepared in Example 1 of this invention is shown in the image. Figure 3 The image shows the microhardness test results of the alloy prepared in Example 1 of this invention. Figure 4 The metallographic structure of the alloy prepared in Example 2 of this invention is shown in the image. Figure 5 This is a microhardness test image of the alloy prepared in Example 2 of the present invention; Figure 6 The metallographic structure of the alloy prepared in Example 3 of this invention is shown in the image. Figure 7 This is a microhardness test image of the alloy prepared in Example 3 of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0036] In this embodiment of the invention, all chemical reagents not specifically mentioned were commercially available analytical grade reagents used in the experiments.

[0037] In this embodiment of the invention, the alloy composition is shown in Table 1.

[0038] Table 1 Example 1 The alloy was prepared according to the following method in this embodiment: (1) Raw material preparation: Ag is 56.5g of electrolytic silver plate with a thickness of 5mm, Au is 22g of gold wire with a diameter of 1mm, Pt and Pd are 300 mesh powder, of which Pt is 10g and Pd is 7g, Cu is 4g of oxygen-free copper rod with a diameter of 10mm, and Re is 0.5g of rhenium sheet with a thickness of 0.5mm. The weighing error is controlled within 0.001%.

[0039] (2) Raw material pretreatment: Ag and Cu were ultrasonically cleaned for 5 min with 10% dilute sulfuric acid at a frequency of 28 Hz; Au, Pt and Pd were soaked in a mixture of 5% nitric acid and 1% hydrofluoric acid (8:2) at room temperature for 3 min; Re was ultrasonically treated for 8 min with 15% citric acid solution at a frequency of 23 Hz. After that, all raw materials were rinsed with deionized water and dried in an oven at 100 ℃ for 1 h.

[0040] (3) Vacuum-Atmosphere Alternating Melting: The Ag, Au, Pt, and Pd raw materials after surface purification treatment are placed in a magnesium oxide crucible preheated at 800℃ for 2 hours, and the magnesium oxide crucible is placed in a 5kW medium-frequency vacuum induction furnace. The furnace cavity is evacuated to 5×10 - 4 The medium-frequency induction furnace was set to heat to 1480℃ at a rate of 15℃ / min and melted for 28 min. Then, high-purity argon gas was introduced to 0.08 MPa, and Cu and Re preheated to 500℃ were added. Melting was continued for 18 min, and then the furnace was evacuated again to 5 × 10⁻⁶ MPa. -4 Pa, hold for 9 min to further remove gaseous impurities in the melt, then refill with high-purity argon to 0.08 MPa and hold for 3 min to balance the furnace environment. Repeat the vacuum-hold-argon-hold operation twice to obtain the alloy melt. During the melting process, the melt is continuously stirred at a speed of 25 r / min.

[0041] (4) Directional solidification: The alloy melt is poured into a graphite mold preheated at 420°C for 1 hour through a guide channel preheated to 800°C at a rate of 20 ml / s. The inner wall of the graphite mold is coated with Y2O3. During casting, the temperature of the alloy melt is 1380°C. Then, the bottom of the mold is water-cooled. A temperature gradient of 9°C / cm is constructed from bottom to top. The solidification rate is gradually reduced from 2 mm / min to 0.5 mm / min to obtain a cylindrical alloy ingot with a diameter of 18 mm.

[0042] (5) Gradient plastic processing: After removing 0.5mm of the oxide scale from the alloy ingot, the cylindrical alloy ingot is hot-rolled into a bar with a diameter of 8mm at 820℃, with a reduction of 18% per pass and a speed of 1m / min. Then, the alloy ingot is pickled to remove the oxide scale and coated with a mixture of graphite and castor oil lubricant. After that, the alloy ingot is cold-drawn: the first pass is deformed by 18% at a speed of 3m / min and a die cone angle of 12°; the second pass is deformed by 15% at a speed of 5m / min and a die cone angle of 10°; the third pass is deformed by 12% at a speed of 8m / min and a die cone angle of 8°. After the above three passes of cold drawing, the alloy billet is placed under a vacuum of 1×10 -3 The alloy wire is heated to 380°C in a vacuum environment of Pa and held for 1.2 hours for intermediate annealing. Then the above three-pass deformation and intermediate annealing are repeated until an alloy wire with a diameter of 1 mm is obtained. (6) Multi-field synergistic aging: Arrange the alloy wire on the ceramic fixture and place the ceramic fixture into a small vacuum aging furnace with a DC magnetic field (temperature control accuracy ±1℃), so that the wire axis is aligned with the magnetic field direction, set the DC magnetic field strength to 0.3T, and evacuate the furnace cavity to 5×10 -4The pressure was increased to 190°C at a rate of 5°C / min and held for 3 hours. Then, the pressure was increased to 270°C and held for 2 hours. After the furnace temperature dropped below 100°C, argon gas was introduced to a pressure of 0.1 MPa, and the furnace was cooled to obtain a silver-gold-platinum-palladium-copper-rhenium alloy wire.

[0043] The alloy wire of this embodiment was tested and found to have a Vickers hardness of 446.89 HV, a resistivity of 3.528 µΩ·cm, an insertion / extraction life of 48,000 cycles, and a diameter tolerance of ±0.08 mm.

[0044] Example 2 The alloy was prepared according to the following method in this embodiment: (1) Raw material preparation: Ag is 52.7g of electrolytic silver plate with a thickness of 5mm, Au is 24g of gold wire with a diameter of 1mm, Pt and Pd are 300 mesh powder, of which Pt is 11g and Pd is 6g, Cu is 4.7g of oxygen-free copper rod with a diameter of 10mm, and Re is 0.3g of rhenium sheet with a thickness of 0.5mm. The weighing error is controlled within 0.001%.

[0045] (2) Raw material pretreatment: Ag and Cu were ultrasonically cleaned for 5 min with 10% dilute sulfuric acid at a frequency of 25 Hz; Au, Pt and Pd were soaked in a mixture of 5% nitric acid and 1% hydrofluoric acid (8:2) at room temperature for 3 min; Re was ultrasonically treated for 8 min with 15% citric acid solution at a frequency of 20 Hz. After that, all raw materials were rinsed with deionized water and dried in an oven at 100 ℃ for 1 h.

[0046] (3) Vacuum-Atmosphere Alternating Melting: The Ag, Au, Pt, and Pd raw materials after surface purification treatment are placed in a magnesium oxide crucible preheated at 800℃ for 2 hours, and the magnesium oxide crucible is placed in a 5kW medium-frequency vacuum induction furnace. The furnace cavity is evacuated to 4×10 - 4 The medium-frequency induction furnace was set to heat to 1450℃ at a rate of 15℃ / min and melted for 30 min. Then, high-purity argon gas was introduced to 0.08 MPa, and Cu and Re preheated to 500℃ were added. Melting was continued for 20 min. Finally, the furnace was evacuated again to 4 × 10⁻⁶ MPa. -4 The pressure was increased to 0.06 MPa and held for 10 minutes to further remove gaseous impurities from the melt. High-purity argon was then introduced again to 0.06 MPa and held for 4 minutes to balance the furnace environment. The vacuum-hold-argon-hold operation was repeated twice to obtain the alloy melt. During the melting process, the melt was continuously stirred at a speed of 30 r / min.

[0047] (4) Directional solidification: The alloy melt is poured into a graphite mold preheated at 450°C for 1 hour through a guide channel preheated to 800°C at a rate of 15 ml / s. The inner wall of the graphite mold is coated with Y2O3. During casting, the temperature of the alloy melt is 1350°C. Then, the bottom of the mold is water-cooled. A temperature gradient of 8°C / cm is constructed from bottom to top. The solidification rate is gradually reduced from 2 mm / min to 0.5 mm / min to obtain a cylindrical alloy ingot with a diameter of 15 mm.

[0048] (5) Gradient plastic processing: After removing 0.5mm of the oxide scale from the alloy ingot, the cylindrical alloy ingot is hot-rolled into a bar with a diameter of 5mm at 800℃, with a reduction of 15% per pass and a speed of 1m / min. Then, the alloy ingot is pickled to remove the oxide scale and coated with a mixture of graphite and castor oil lubricant. After that, the alloy ingot is cold-drawn: the first pass is deformed by 18% at a speed of 3m / min and a die cone angle of 12°; the second pass is deformed by 15% at a speed of 5m / min and a die cone angle of 10°; the third pass is deformed by 12% at a speed of 8m / min and a die cone angle of 8°. After the above three passes of cold drawing, the alloy billet is placed in a vacuum of 1×10 -3 The alloy wire is heated to 350°C in a vacuum environment of Pa and held for 1.5 hours for intermediate annealing. Then the above three-pass deformation and intermediate annealing are repeated until an alloy wire with a diameter of 0.5 mm is obtained. (6) Multi-field synergistic aging: Arrange the alloy wire on the ceramic fixture and place the ceramic fixture into a small vacuum aging furnace with a DC magnetic field (temperature control accuracy ±1℃), so that the wire axis is aligned with the magnetic field direction, set the DC magnetic field strength to 0.3T, and evacuate the furnace cavity to 5×10⁻ 4 The pressure was increased to 180°C at a rate of 5°C / min and held for 3 hours. Then, the pressure was increased to 260°C and held for 2 hours. After the furnace temperature dropped below 100°C, argon gas was introduced to a pressure of 0.1 MPa, and the furnace was cooled to obtain a silver-gold-platinum-palladium-copper-rhenium alloy.

[0049] The alloy wire of this embodiment was tested and found to have a Vickers hardness of 443.64 HV, a resistivity of 3.347 µΩ·cm, an insertion / extraction life of 53,000 cycles, and a diameter tolerance of ±0.09 mm.

[0050] Example 3 The alloy was prepared according to the following method in this embodiment: (1) Raw material preparation: Ag is 60.2g of 5mm thick electrolytic silver plate, Au is 20g of 1mm diameter gold wire, Pt and Pd are 300 mesh powder, of which Pt is 8g and Pd is 8g, Cu is 3g of 10mm diameter oxygen-free copper rod, Re is 0.8g of 0.5mm thick rhenium sheet, and the weighing error is controlled within 0.001%.

[0051] (2) Raw material pretreatment: Ag and Cu were ultrasonically cleaned for 5 min with 10% dilute sulfuric acid at a frequency of 30 Hz; Au, Pt and Pd were soaked in a mixture of 5% nitric acid and 1% hydrofluoric acid (8:2) at room temperature for 3 min; Re was ultrasonically treated for 8 min with 15% citric acid solution at a frequency of 25 Hz. After that, all raw materials were rinsed with deionized water and dried in an oven at 100 ℃ for 1 h.

[0052] (3) Vacuum-Atmosphere Alternating Melting: The Ag, Au, Pt, and Pd raw materials after surface purification treatment are placed in a magnesium oxide crucible preheated at 800℃ for 2 hours, and the magnesium oxide crucible is placed in a 5kW medium-frequency vacuum induction furnace. The furnace cavity is evacuated to 3×10 - 4 The medium-frequency induction furnace was set to heat to 1500℃ at a rate of 15℃ / min and melted for 25 min. Then, high-purity argon gas was introduced to 0.08 MPa, and Cu and Re preheated to 500℃ were added and melted for 15 min. Finally, the furnace was evacuated again to 3×10⁻⁶ MPa. -4 The pressure was increased to 0.05 MPa and held for 8 minutes to further remove gaseous impurities from the melt. High-purity argon was then introduced again to 0.05 MPa and held for 5 minutes to balance the furnace environment. The vacuum-hold-argon-hold operation was repeated twice to obtain the alloy melt. During the melting process, the melt was continuously stirred at a speed of 20 r / min.

[0053] (4) Directional solidification: The alloy melt is poured into a graphite mold preheated at 400°C for 1 hour through a guide channel preheated to 800°C at a rate of 25 ml / s. The inner wall of the graphite mold is coated with Y2O3. During casting, the temperature of the alloy melt is 1400°C. Then, the bottom of the mold is water-cooled. A temperature gradient of 10°C / cm is constructed from bottom to top. The solidification rate is gradually reduced from 2 mm / min to 0.5 mm / min to obtain a cylindrical alloy ingot with a diameter of 20 mm.

[0054] (5) Gradient plastic processing: After removing 0.5mm of the oxide scale from the alloy ingot, the cylindrical alloy ingot is hot-rolled into a bar with a diameter of 10mm at 850℃, with a reduction of 16% per pass and a speed of 1m / min. Then, the alloy ingot is pickled to remove the oxide scale and coated with a mixture of graphite and castor oil lubricant. After that, the alloy ingot is cold-drawn: the first pass is deformed by 18% at a speed of 3m / min and a die cone angle of 12°; the second pass is deformed by 15% at a speed of 5m / min and a die cone angle of 10°; the third pass is deformed by 12% at a speed of 8m / min and a die cone angle of 8°. After the above three passes of cold drawing, the alloy billet is placed in a vacuum of 1×10 -3The alloy wire is heated to 400°C in a vacuum environment of Pa and held for 1 hour for intermediate annealing. Then the above three-pass deformation and intermediate annealing are repeated until an alloy wire with a diameter of 1.5 mm is obtained.

[0055] (6) Multi-field synergistic aging: Arrange the alloy wire on the ceramic fixture and place the ceramic fixture into a small vacuum aging furnace with a DC magnetic field (temperature control accuracy ±1℃), so that the wire axis is aligned with the magnetic field direction, set the DC magnetic field strength to 0.3T, and evacuate the furnace cavity to 5×10⁻ 4 The pressure was increased to 200℃ in a vacuum aging furnace at a rate of 5℃ / min, and held for 3 hours. Then, the temperature was increased to 280℃ in the vacuum aging furnace and held for 2 hours. After the furnace temperature dropped below 100℃, argon gas was introduced to 0.1MPa, and the furnace was cooled to obtain a silver-gold-platinum-palladium-copper-rhenium alloy.

[0056] The alloy of this embodiment was tested and found to have a Vickers hardness of 438.68 HV, a resistivity of 3.908 µΩ·cm, an insertion and extraction life of 50,000 cycles, and a diameter tolerance of ±0.001 mm.

[0057] pass Figure 2 It can be seen that the metallographic structure of the silver-gold-platinum-palladium-copper-rhenium alloy in Example 1 exhibits a multi-phase interweaving characteristic: various morphologies and colors of phases (light pink / purple, dark gray-black) are distributed among each other, consisting of a matrix phase and a dispersed second phase, which is caused by the segregation or formation of intermetallic compounds during element solidification and heat treatment; each phase is uniformly dispersed, without obvious large blocks or network concentrations, reflecting that the preparation process has good control over the mixing and mixing of components, ensuring consistent performance; a large number of micron-sized and smaller fine particles and irregular second phases can actively improve the strength and hardness of the alloy through dispersion strengthening.

[0058] pass Figure 3 As can be seen, the microindentation of the silver-gold-platinum-palladium-copper-rhenium alloy in Example 1 is a clear square pyramid shape without severe fragmentation or breakage, demonstrating good strength-toughness matching and good plastic-elastic deformation synergy. The multiphase dispersion structure achieves high hardness through solid solution and dispersion strengthening. No phase separation or cracking is observed in the indentation and surrounding area, confirming that the phase distribution and interfacial bonding ensure stable testing. Instrument testing shows that its Vickers hardness is 446.89 HV. This property is beneficial for improving the high-frequency insertion and removal wear resistance and fracture resistance of chip detection probes, providing microscopic support for practical applications.

[0059] pass Figure 4It can be seen that the microstructure of the silver-gold-platinum-palladium-copper-rhenium alloy in Case 2 exhibits a multi-phase structure with various colored phases (light pink, yellow-green, etc.), suggesting the presence of a matrix phase and a dispersed second phase. This structure is attributed to the segregation of elements during solidification and heat treatment, or the formation of intermetallic compounds. The overall phase distribution is dispersed and uniform, without significant large agglomerations or continuous network structures, indicating that the preparation process effectively controls the mixing and mixing of components, which is beneficial for ensuring the stability of the alloy's properties. The presence of numerous micron-sized and irregularly shaped second phases suggests that these dispersed second phases can contribute to improving the alloy's strength, hardness, and other mechanical properties through a strengthening mechanism. pass Figure 5 As can be seen, the square pyramidal diamond indentation outline of the silver-gold-platinum-palladium-copper-rhenium alloy in Case 2 is clear and without severe brittleness, demonstrating the good matching of strength and toughness and the good coordination of plastic-elastic deformation under local high pressure. Combined with the multiphase dispersion structure, solid solution and dispersion strengthening create high hardness. There is no separation or cracking in the indentation and its surrounding area, which confirms the uniformity of phase distribution and interfacial bonding, ensuring stable hardness. Instrument testing shows that its Vickers hardness is 443.64 HV. This property is beneficial to improving the wear resistance life and fracture risk of chip detection probe insertion and removal, providing microscopic support for practical applications.

[0060] pass Figure 6 As can be seen, the metallographic structure of the silver-gold-platinum-palladium-copper-rhenium alloy in Implementation Case 3 exhibits multiphase interweaving characteristics: light pink, yellow-green, and other colored phases are uniformly and diffusely distributed, forming a multiphase structure, which includes a matrix phase and a dispersed second phase, resulting from the segregation or formation of intermetallic compounds during element solidification and heat treatment; the phase distribution shows no obvious large agglomerates or continuous network structure, reflecting the effectiveness of the preparation process in mixing and controlling the composition, which is conducive to ensuring the stability of the alloy performance; a large number of micron-sized and irregularly shaped second phases, through dispersion strengthening, can help improve the alloy's strength and hardness. pass Figure 7 As can be seen in Implementation Case 3, the silver-gold-platinum-palladium-copper-rhenium alloy exhibits clearly defined and regular square pyramidal diamond indenters without obvious brittle cracking. This reflects the good coordination of plastic-elastic deformation and excellent strength-toughness matching under local high pressure. Combined with the multiphase dispersed structure, the absence of separation and cracking in the indentation and its surrounding area confirms that the phase distribution and interfacial bonding ensure stable hardness and demonstrate resistance to plastic deformation. Instrument testing yielded a Vickers hardness of 438.68 HV, which can provide support for wear resistance and fracture resistance in high-frequency insertion and removal scenarios, thus improving the reliability of probe service.

[0061] In summary, by optimizing the alloy composition and combining it with the synergistic effect of the preparation method, this invention can prepare an alloy with a hardness of over 400 HV, a resistivity of less than 4 µΩ·cm, and an insertion / extraction life of over 50,000 cycles, fully meeting the stringent performance requirements of chip test probes.

[0062] Finally, it should be noted that the above preferred 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 through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and in detail without departing from the scope defined by the claims of the present invention.

Claims

1. A silver-gold-platinum-palladium-copper-rhenium alloy, characterized in that: The alloy composition, by mass percentage, includes: Au: 20%~25%, Pt: 8%~12%, Pd: 5%~8%, Cu: 3%~5%, Re: 0.3%~0.8%, with the balance being Ag.

2. The method for preparing a silver-gold-platinum-palladium-copper-rhenium alloy according to claim 1, characterized in that: The preparation method includes the following steps: (1) Raw material pretreatment: Weigh Ag, Au, Pt, Pd, Cu and Re raw materials according to the alloy mass percentage, and then perform surface purification treatment on the raw materials; (2) Vacuum-atmosphere alternating melting: The Ag, Au, Pt and Pd raw materials after surface purification treatment in step (1) are subjected to vacuum induction melting. After the raw materials are melted, the temperature is kept constant and inert gas is introduced. Preheated Cu and Re raw materials are added to continue melting. Then the vacuuming and inert gas introduction operations are repeated twice to obtain the alloy melt. (3) Directional solidification casting: The alloy melt obtained in step (2) is cast and directional solidification is carried out by controlling the alloy melt to generate a gradually increasing temperature gradient from bottom to top to obtain an alloy ingot; (4) Multi-pass plastic processing: The alloy ingot obtained in step (3) is subjected to hot rolling and multi-pass cold drawing to obtain alloy wire, wherein vacuum intermediate annealing is performed after every 3 passes of cold drawing. (5) Multi-field synergistic aging: Under DC magnetic field and vacuum conditions, the alloy wire obtained in step (4) is subjected to step aging treatment. Then, when the alloy wire is cooled to below 100°C in the furnace, argon gas is introduced to allow the alloy wire to continue cooling to room temperature in the furnace, thus obtaining silver-gold-platinum-palladium-copper-rhenium alloy wire.

3. The preparation method according to claim 2, characterized in that: In step (1), the specific methods of surface purification treatment include: Ag and Cu raw materials are ultrasonically cleaned with dilute sulfuric acid; Au, Pt, and Pd raw materials are soaked at room temperature with a mixture of nitric acid and hydrofluoric acid; Re raw materials are ultrasonically treated with citric acid solution, and then all raw materials are rinsed and vacuum dried in sequence to complete the surface purification treatment.

4. The preparation method according to claim 3, characterized in that: The concentration of the dilute sulfuric acid is 10%, and the ultrasonic cleaning time for Ag and Cu raw materials is 5 minutes at a frequency of 25-30 kHz. The concentration of the nitric acid is 5%, and the concentration of the hydrofluoric acid is 1%. In the mixed solution, the volume ratio of nitric acid to hydrofluoric acid is 4:

1. The soaking time for Au, Pt, and Pd raw materials at room temperature is 3 minutes. The concentration of the citric acid solution is 15%, and the ultrasonic treatment time for Re raw materials is 8 minutes at a frequency of 20-25 kHz. All raw materials are rinsed with deionized water. The vacuum drying temperature is 100°C, and the vacuum drying time is 1 hour.

5. The preparation method according to claim 2, characterized in that: In step (2), the vacuum degree during vacuum induction melting is ≤5×10 -4 The melting temperature is 1450~1500℃, and the melting time of Ag, Au, Pt, and Pd raw materials is 25~30min. Inert gas is introduced to 0.08MPa, and after adding Cu and Re, the melting time continues for 15~20min. This process is then repeated until the vacuum level is ≤5×10⁻⁶. -4 The pressure is maintained at 0.05-0.08 MPa for 8-10 minutes, and then inert gas is introduced to maintain the pressure at 0.05-0.08 MPa for 3-5 minutes. This process is repeated twice. The inert gas is argon. The melt is continuously stirred at a speed of 20-30 r / min throughout the vacuum induction melting process.

6. The preparation method according to claim 5, characterized in that: The preheating temperature of Cu and Re is 500℃.

7. The preparation method according to claim 2, characterized in that: In step (3), the mold used for casting is preheated to 400~450℃. During casting, the temperature of the alloy melt is 1350~1400℃, the casting speed is 15~25ml / s, and the temperature gradient of directional solidification increases from bottom to top at 8~10℃ / cm. After complete solidification, a cylindrical ingot with a diameter of 15~20mm is obtained.

8. The preparation method according to claim 2 or 7, characterized in that: In step (4), the hot rolling temperature is 800~850℃, the single-pass reduction is 15%~18%, the hot rolling speed is 1m / min, and the alloy ingot is formed into a bar with a diameter of 5~10mm after hot rolling. Each set of three cold drawing passes constitutes a set of cold drawing treatments, in which the deformation amounts of the three cold drawing passes are 18%, 15%, and 12% respectively, and the cold drawing speeds are 3m / min, 5m / min, and 8m / min respectively. Multiple sets of cold drawing treatments are performed in a cycle to draw the bar into an alloy wire with a diameter of 0.5~1.5mm. The intermediate annealing temperature is 350~400℃, and the intermediate annealing time is 1~1.5h.

9. The preparation method according to claim 2, characterized in that: In step (5), the DC magnetic field strength is 0.3T, and the specific process of stage aging treatment is as follows: heat the alloy wire to 180~200℃, keep it at that temperature for 3h, and then raise the temperature to 260~280℃ and keep it at that temperature for 2h.

10. The application of the silver-gold-platinum-palladium-copper-rhenium alloy as described in claim 1 in the fabrication of chip test probes, characterized in that: The method for fabricating the chip test probe includes the following steps: S1: Use colloidal silica polishing slurry with a particle size of 50nm and pH=7.5~8.5 to perform mechanical and chemical polishing on the silver-gold-platinum-palladium-copper-rhenium alloy wire. During the polishing process, the polishing pressure is 0.03~0.05MPa, the stirring speed is 20~30r / min, and the mechanical and chemical polishing time is 10~15min. S2: Use argon gas to perform ion sputtering cleaning on the filament material after mechanical and chemical polishing in step S1, wherein the cleaning power is 150W and the cleaning time is 5~8min; S3: Graphite is sputtered onto the surface of the filament to form a diamond-like carbon (DLC) coating. The sputtering temperature is ≤180℃, the sputtering power is 300W, and sputtering is stopped when the DLC coating thickness reaches 80~100nm. The filament is then subjected to vacuum insulation treatment to obtain the chip test probe. The vacuum insulation vacuum degree is 1×10⁻⁶. -3 Pa, the heat preservation temperature is 150~200℃, and the heat preservation time is 1~1.5h.

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