A nickel-silicon-based copper alloy strip for integrated circuits and its preparation method

Abstract

The present invention discloses a nickel-silicon-based copper alloy strip for integrated circuits and a preparation method thereof, belonging to the technical field of copper alloy strips. The preparation method includes subjecting a nickel-silicon-based copper alloy ingot to sawing, hot rolling for blooming, surface milling, rough rolling, thick shearing, annealing and cleaning treatments. The nickel-plated zirconia powder helps other metal elements form paths in its pores, reducing the influence on electrical conductivity and thermal conductivity, and improving the mechanical properties of the strip through its pinning effect. Finally, the prepared nickel-silicon-based copper alloy strip has a smooth surface, uniform color and a matte state, and has high tensile strength, electrical conductivity, anti-softening temperature and thermal conductivity in terms of performance. After a 90° bending test, it still has a good appearance state, meeting the usage requirements of integrated circuits.

Description

Technical Field

[0001] The present invention belongs to the technical field of copper alloy strips, and specifically relates to a nickel-silicon-based copper alloy strip for integrated circuits and a preparation method thereof. Background Art

[0002] Nickel-silicon-based copper alloy strips are alloy materials formed with copper as the matrix by adding nickel (Ni) and silicon (Si) elements. They have high strength, high electrical conductivity, good heat resistance and corrosion resistance, and are widely used in the fields of electronics, electricity, automobiles, communications, etc. The addition of nickel and silicon significantly improves the alloy strength through solid solution strengthening and aging precipitation mechanisms, while maintaining the high electrical conductivity of the copper matrix. The aging treatment at 450 °C can further precipitate the Ni2Si phase, achieving the effects of refining grains, optimizing strength and balancing electrical conductivity.

[0003] Nickel-silicon-based copper alloy strips are particularly suitable for integrated circuits and can be used as key components such as lead frames, connectors, terminals, and packaging substrates. The Chinese invention patent with the publication number CN116732384B discloses a copper-nickel-silicon alloy ingot and a preparation method thereof. By introducing rare earth elements and zirconium elements, equiaxed crystals instead of columnar crystals can be formed during the casting of the copper-nickel-silicon alloy, thereby refining the grains and avoiding hot rolling cracking, providing an excellent copper-nickel-silicon alloy ingot for hot rolling.

[0004] However, in the above method, the zirconium phase is dispersed in the alloy ingot in the form of a solid solution, which may form a high-resistance Cu5Zr phase with copper, resulting in a decrease in the electrical conductivity of the nickel-silicon-based copper alloy strip, thus affecting its application in integrated circuits. Summary of the Invention

[0005] The purpose of the present invention is to provide a nickel-silicon-based copper alloy strip for integrated circuits and a preparation method thereof. The zirconium phase is added to the nickel-silicon-based copper alloy strip in the form of porous zirconia. Through the pinning effect, the grain size is reduced, the mechanical properties are improved, and at the same time, the electronic transmission is not affected and the electrical conductivity is not affected, meeting the usage requirements of integrated circuits.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A preparation method of a nickel-silicon-based copper alloy strip for integrated circuits includes the following steps:

[0008] Step 1: Nickel hydroxide precipitate is formed in Zr-MOF by nickel nitrate and ammonia water, and then calcined in an air atmosphere. After obtaining zirconium-nickel composite oxide powder and undergoing reduction treatment, nickel-plated zirconia powder is obtained.

[0009] Step 2: Add metallic nickel and copper-magnesium alloy into a vacuum melting furnace, evacuate the air to 10 Pa, heat to completely melt the raw materials under the condition of 1300 - 1350 °C, take samples for analysis, adjust the addition amounts of metallic nickel and copper-magnesium alloy according to the analysis results, add a refining agent accounting for 0.12 - 0.15% of the melt mass and continue refining for 20 - 30 min. After slag removal, add copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy under argon protection, continue melting for 10 - 15 min, take samples for analysis, adjust the addition amounts of copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy according to the analysis results, keep the nickel-plated zirconia powder warm for 20 - 30 min under argon protection and at 300 - 350 °C to remove the adsorbed gas, then inject the degassed nickel-plated zirconia powder into the melt by argon carrier gas injection method, continue melting for 30 - 40 min, take samples for analysis, adjust the addition amount of nickel-plated zirconia powder according to the analysis results, carry out ultrasonic treatment for 3 - 5 min at a frequency of 30 - 40 kHz to break the agglomerates, and then cast the melt into shape by vertical continuous casting. The ingot discharging temperature at the lower part of the mold is 600 - 800 °C, and spray cooling is carried out by using a spray ring to obtain a nickel-silicon-based copper alloy ingot.

[0010] Step 3: Subject the nickel-silicon-based copper alloy ingot to sawing, hot rolling for blooming, facing, rough rolling, heavy shearing, annealing and cleaning treatments to obtain a nickel-silicon-based copper alloy strip for integrated circuits with a thickness of 0.3 - 1.5 mm.

[0011] Furthermore, the mass percentage composition of the nickel-silicon-based copper alloy ingot is: Ni 2 - 3%, Si 0.2 - 0.4%, La 0.05 - 0.09%, Zr 0.05 - 0.06%, Mg 0.02 - 0.04%, and the balance is Cu and inevitable impurities.

[0012] Furthermore, the refining agent is composed of borax and phosphor copper mixed according to a mass ratio of 5:1.

[0013] Furthermore, the zirconium-nickel composite oxide powder is prepared through the following steps:

[0014] Transfer Zr-MOF and a nickel nitrate solution with a mass fraction of 10% to a reaction kettle, stir at 200 - 500 r / min for 10 - 20 min, carry out ultrasonic dispersion for 5 - 10 min, adjust the pH value to 7.5 - 8.5 with ammonia water, carry out vacuum impregnation at 50 - 60 °C and 0.05 - 0.08 MPa for 1 - 2 h, stand at room temperature for aging for 6 - 8 h, carry out centrifugal filtration, vacuum-dry the precipitate to constant weight, then transfer it to a tubular furnace, under an air atmosphere, heat it to 250 - 300 °C at a rate of 2 - 3 °C / min and keep it warm for 2 - 4 h, then heat it to 700 - 800 °C at a rate of 4 - 5 °C / min and keep it warm for 2 - 3 h, naturally cool to room temperature, grind and crush to obtain the zirconium-nickel composite oxide powder.

[0015] Furthermore, the dosage ratio of Zr-MOF to nickel nitrate solution is 1 g: 5-10 mL.

[0016] Furthermore, the nickel-plated zirconia powder is prepared by the following steps:

[0017] Transfer the zirconium-nickel composite oxide powder to a tubular furnace, keep it warm for 1-2 h under a hydrogen atmosphere and at 500-600 °C, naturally cool it to room temperature, grind and crush it to obtain the nickel-plated zirconia powder, and transfer it to a nitrogen-filled container for storage and standby.

[0018] Furthermore, Zr-MOF is prepared by the following steps:

[0019] Add zirconium chloride, terephthalic acid and N,N-dimethylformamide to a reaction kettle, stir and mix them, then stir and react for 10-12 h under the conditions of 140-160 °C and 200-300 r / min, naturally cool it to room temperature, centrifuge and filter, wash the precipitate with absolute ethanol and deionized water 2-3 times respectively, and vacuum dry it to constant weight to obtain Zr-MOF.

[0020] Furthermore, the mass ratio of zirconium chloride, terephthalic acid and N,N-dimethylformamide is 2-2.33: 1.4-1.66: 300-360.

[0021] Advantages of the present invention:

[0022] 1. The nickel-silicon-based copper alloy strip of the present invention has a smooth surface, uniform color and a matte state. In terms of performance, it has high tensile strength, electrical conductivity, anti-softening temperature and thermal conductivity. After a 90° bending test, it still has a good apparent state, meeting the use requirements of integrated circuits.

[0023] 2. During the casting process of the nickel-silicon-based copper alloy ingot of the present invention, the nickel-plated zirconia powder is injected into the melt by argon carrier gas spraying method, which helps the nickel-plated zirconia powder to be evenly dispersed in the melt.

[0024] The nickel-plated zirconia powder uses porous Zr-MOF as the matrix. By using the metathesis reaction of nickel nitrate and ammonia water, nickel hydroxide precipitates are formed on the surface and in the pores of Zr-MOF, and then calcined in an air atmosphere. The organic matter in Zr-MOF decomposes to generate carbon dioxide and volatilizes, leaving zirconia with a three-dimensional porous structure, while nickel hydroxide decomposes into nickel oxide, which plays a role in supporting the spatial structure. After reduction treatment, since the reduction temperature of zirconia > 1000 °C, nickel oxide is reduced to nickel metal at a lower temperature and coats the porous zirconia, improving its electrical conductivity, and using the wettability of nickel to improve the uniform dispersion of the nickel-plated zirconia powder in the melt and reduce particle segregation.

[0025] 3. In the nickel-silicon-based copper alloy strip of the present invention, the zirconia phase exists in a porous form. Due to the infiltration and filling of metallic nickel, it helps to reduce the formation of pores to form a closed-pore structure, thereby deflecting cracks and increasing the toughness of the strip. And the nickel-plated zirconia powder helps other metal elements to form channels in its pores, reducing the influence on electrical conductivity and thermal conductivity, and improving the mechanical properties of the strip through its pinning effect, which helps the application of this nickel-silicon-based copper alloy strip in high-end integrated circuits. Detailed implementation mode

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of protection of the present invention.

[0027] Example 1: A nickel-silicon-based copper alloy strip for integrated circuits is prepared by the following method:

[0028] S1: Add 2 kg of zirconium chloride, 1.4 kg of terephthalic acid, and 300 kg of N,N-dimethylformamide into a reaction kettle and stir and mix them. Then, stir and react at 140 °C and 200 r / min for 10 h, naturally cool to room temperature, centrifuge and filter. Wash the precipitate twice with anhydrous ethanol and deionized water respectively, and vacuum dry to constant weight to obtain Zr-MOF.

[0029] S2: Transfer 1 kg of Zr-MOF and 5 L of a nickel nitrate solution with a mass fraction of 10% to a reaction kettle, stir at 200 r / min for 10 min, ultrasonically disperse for 5 min, adjust the pH value to 7.5 with ammonia water, vacuum impregnate at 50 °C and 0.05 MPa for 1 h, stand at room temperature for aging for 6 h, centrifuge and filter. Vacuum dry the precipitate to constant weight, then transfer it to a tube furnace. In an air atmosphere, heat it to 250 °C at a rate of 2 °C / min and hold for 2 h, then heat it to 700 °C at a rate of 4 °C / min and hold for 2 h, naturally cool to room temperature, grind and crush to obtain zirconium-nickel composite oxide powder.

[0030] S3: Transfer the zirconium-nickel composite oxide powder to a tube furnace, hold it at 500 °C in a hydrogen atmosphere for 1 h, naturally cool to room temperature, grind and crush to obtain nickel-plated zirconia powder, and transfer it to a nitrogen-filled container for storage and standby.

[0031] S4: Mix borax and phosphor bronze in a mass ratio of 5:1 to obtain a refining agent. Add metallic nickel and copper-magnesium alloy into a vacuum melting furnace, evacuate to 10 Pa, heat to 1300 °C until the raw materials are completely melted, take samples for analysis, adjust the addition amounts of metallic nickel and copper-magnesium alloy according to the analysis results, add 0.12% of the refining agent based on the mass of the melt after the raw materials are completely melted and continue refining for 20 min. After slag removal, add copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy under argon protection, continue melting for 10 min, take samples for analysis, adjust the addition amounts of copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy according to the analysis results. Keep the nickel-plated zirconia powder under argon protection and at 300 °C for 20 min to remove the adsorbed gas, then inject the degassed nickel-plated zirconia powder into the melt by argon carrier gas injection method, continue melting for 30 min, take samples for analysis, adjust the addition amount of the nickel-plated zirconia powder according to the analysis results, ultrasonically treat for 3 min at a frequency of 30 kHz to break the agglomerates, and then cast the melt into a shape by vertical continuous casting. The ingot discharging temperature at the lower part of the mold is 600 °C, and spray cooling is carried out by a spray ring to obtain a nickel-silicon series copper alloy ingot.

[0032] Among them, the mass percentage composition of the nickel-silicon series copper alloy ingot is: Ni 2%, Si 0.4%, La 0.05%, Zr 0.05%, Mg 0.02%, and the balance is Cu and unavoidable impurities.

[0033] S5: Subject the nickel-silicon series copper alloy ingot to sawing, hot rolling for blooming, milling, rough rolling, heavy shearing, annealing and cleaning treatments to obtain a nickel-silicon series copper alloy strip for integrated circuits with a thickness of 0.3 mm.

[0034] Among them, the hot rolling temperature is 950 °C, the holding time is 1.5 h, and the rolling speed is 0.5 m / s; the rough rolling temperature is 200 °C, and the rolling speed is 1 m / s; the heavy shearing temperature is 150 °C, and the shearing force is 300 kN; the annealing temperature is 500 °C, and the holding time is 2 h; the cleaning treatment includes polishing, pickling, water washing, passivation, water washing and drying. The pickling agent is a sulfuric acid solution with a mass fraction of 18±0.5%, and the passivation agent is a benzotriazole solution with a mass fraction of 0.15%.

[0035] Detect the properties of the prepared nickel-silicon series copper alloy strip. After grinding the strip, randomly collect five fields of view by scanning electron microscope to calculate the average grain size; detect the tensile strength of the strip with reference to GB / T 228.1-202X; detect the conductivity of the strip with reference to GB / T 32791-2016; test the anti-softening temperature of the strip with reference to GB / T 33370-2016; test the thermal conductivity of the strip with reference to ASTM E1461-13; conduct a 90° bending test with reference to GB / T 232-2024 to detect the bending performance of the strip and observe its apparent state.

[0036] Using a transmission electron microscope, five points were randomly selected from the copper matrix part of the strip cross-section for EDS analysis. The detection intensity of oxygen element was measured and the average value was set as Ia. Then, the particles with different contrast from the copper matrix in this observation area were used as the detection objects and EDS analysis was carried out under the same conditions. The number of particles with an oxygen element detection intensity more than 10 times that of Ia was measured, so as to detect the number of oxygen-containing precipitated phase particles. The results are shown in Table 1.

[0037] Example 2: A nickel-silicon-based copper alloy strip for integrated circuits was prepared by the following method:

[0038] S1: 2.165 kg of zirconium chloride, 1.53 kg of terephthalic acid and 330 kg of N,N-dimethylformamide were added to the reaction kettle and stirred and mixed. Then, under the conditions of 150 °C and 250 r / min, the reaction was stirred for 11 h, cooled naturally to room temperature, centrifuged and filtered. The precipitate was washed 2.5 times with absolute ethanol and deionized water respectively, and vacuum dried to constant weight to obtain Zr-MOF.

[0039] S2: 1 kg of Zr-MOF and 7.5 L of a nickel nitrate solution with a mass fraction of 10% were transferred to the reaction kettle, stirred at 350 r / min for 15 min, ultrasonically dispersed for 7.5 min, and the pH value was adjusted to 8.0 with ammonia water. Under the conditions of 55 °C and 0.065 MPa, vacuum impregnation was carried out for 1.5 h, left to age at room temperature for 7 h, centrifuged and filtered. The precipitate was vacuum dried to constant weight, and then transferred to a tube furnace. Under an air atmosphere, it was heated to 275 °C at a rate of 2.5 °C / min and held for 3 h, and then heated to 750 °C at a rate of 4.5 °C / min and held for 2.5 h, and cooled naturally to room temperature, ground and pulverized to obtain zirconium-nickel composite oxide powder.

[0040] S3: The zirconium-nickel composite oxide powder was transferred to a tube furnace, held at 550 °C for 1.5 h under a hydrogen atmosphere, cooled naturally to room temperature, ground and pulverized to obtain nickel-plated zirconia powder, which was transferred to a nitrogen-filled container for storage and standby.

[0041] S4: The refining agent is obtained by mixing borax and phosphor bronze in a mass ratio of 5:1. Add metallic nickel and copper-magnesium alloy into a vacuum melting furnace, evacuate to 10 Pa, heat to 1325 °C until the raw materials are completely melted, take samples for analysis, adjust the addition amounts of metallic nickel and copper-magnesium alloy according to the analysis results, add 0.135% of the refining agent based on the mass of the melt and continue refining for 25 min. After slag removal, add copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy under argon protection, continue melting for 12.5 min, take samples for analysis, adjust the addition amounts of copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy according to the analysis results. Keep the nickel-plated zirconia powder at 325 °C for 25 min under argon protection to remove the adsorbed gas, and then inject the degassed nickel-plated zirconia powder into the melt by argon carrier gas injection method, continue melting for 35 min, take samples for analysis, adjust the addition amount of the nickel-plated zirconia powder according to the analysis results, perform ultrasonic treatment at a frequency of 35 kHz for 4 min to break the agglomerates, and then cast the melt into a shape by vertical continuous casting. The ingot discharging temperature at the lower part of the mold is 700 °C, and spray cooling is carried out by a spray ring to obtain a nickel-silicon series copper alloy ingot.

[0042] Among them, the mass percentage composition of the nickel-silicon series copper alloy ingot is: Ni 2.5%, Si 0.3%, La 0.07%, Zr 0.055%, Mg 0.03%, and the balance is Cu and inevitable impurities.

[0043] S5: Subject the nickel-silicon series copper alloy ingot to sawing, hot rolling for blooming, milling, rough rolling, heavy shearing, annealing and cleaning treatments to obtain a nickel-silicon series copper alloy strip for integrated circuits with a thickness of 0.9 mm.

[0044] Among them, the hot rolling temperature is 955 °C, the holding time is 1.75 h, and the rolling speed is 1.0 m / s; the rough rolling temperature is 250 °C, and the rolling speed is 2 m / s; the heavy shearing temperature is 225 °C, and the shearing force is 400 kN; the annealing temperature is 525 °C, and the holding time is 2.5 h; the cleaning treatment includes polishing, pickling, water washing, passivation, water washing and drying. The pickling agent is a sulfuric acid solution with a mass fraction of 18 ± 0.5%, and the passivation agent is a benzotriazole solution with a mass fraction of 0.15%.

[0045] Detect the performance of the prepared nickel-silicon series copper alloy strip, and the detection method is the same as that in Example 1, and the results are shown in Table 1.

[0046] Example 3: A nickel-silicon series copper alloy strip for integrated circuits is prepared by the following method:

[0047] S1: Add 2.33 kg of zirconium chloride, 1.66 kg of terephthalic acid, and 360 kg of N,N-dimethylformamide into a reaction kettle, stir and mix them, then stir and react at 160 °C and 300 r / min for 12 h, naturally cool to room temperature, centrifuge and filter, wash the precipitate with absolute ethanol and deionized water three times respectively, and vacuum dry to constant weight to obtain Zr-MOF.

[0048] S2: Transfer 1 kg of Zr-MOF and 10 L of a 10% nickel nitrate solution by mass to a reaction kettle, stir at 500 r / min for 20 min, ultrasonically disperse for 10 min, adjust the pH value to 8.5 with ammonia water, carry out vacuum impregnation at 60 °C and 0.08 MPa for 2 h, let it stand and age at room temperature for 8 h, centrifuge and filter, vacuum dry the precipitate to constant weight, then transfer it to a tubular furnace. Under an air atmosphere, heat it to 300 °C at a rate of 3 °C / min and hold for 4 h, then heat it to 800 °C at a rate of 5 °C / min and hold for 3 h, naturally cool to room temperature, grind and crush to obtain zirconium-nickel composite oxide powder.

[0049] S3: Transfer the zirconium-nickel composite oxide powder to a tubular furnace, hold it at 600 °C under a hydrogen atmosphere for 2 h, naturally cool to room temperature, grind and crush to obtain nickel-plated zirconia powder, and transfer it to a nitrogen-filled container for storage and standby.

[0050] S4: Mix borax and phosphor bronze in a mass ratio of 5:1 to obtain a refining agent; add metallic nickel and copper-magnesium alloy into a vacuum melting furnace, evacuate to 10 Pa, heat to 1350 °C until the raw materials are completely melted, take samples for analysis, adjust the addition amounts of metallic nickel and copper-magnesium alloy according to the analysis results, add 0.15% of the refining agent based on the mass of the melt and continue refining for 30 min. After slag removal, add copper-silicon alloy, copper-lanthanum alloy, and copper-magnesium alloy under argon protection, continue melting for 15 min, take samples for analysis, adjust the addition amounts of copper-silicon alloy, copper-lanthanum alloy, and copper-magnesium alloy according to the analysis results. Hold the nickel-plated zirconia powder at 350 °C for 30 min under argon protection to remove the adsorbed gas, then inject the degassed nickel-plated zirconia powder into the melt by argon carrier gas injection method, continue melting for 40 min, take samples for analysis, adjust the addition amount of the nickel-plated zirconia powder according to the analysis results, ultrasonically treat for 5 min at a frequency of 40 kHz to break the agglomerates, and then cast the melt into a shape by vertical continuous casting. The ingot temperature at the lower part of the mold is 800 °C, and spray cooling is carried out using a spray ring to obtain a nickel-silicon-based copper alloy ingot.

[0051] Among them, the mass percentage composition of the nickel-silicon-based copper alloy ingot is: Ni 3%, Si 0.2%, La 0.09%, Zr 0.06%, Mg 0.04%, and the balance is Cu and inevitable impurities.

[0052] S5: Subject the nickel-silicon-based copper alloy ingot to sawing, hot rolling for blooming, surface milling, rough rolling, thick shearing, annealing, and cleaning treatments to obtain a nickel-silicon-based copper alloy strip for integrated circuits with a thickness of 1.5 mm.

[0053] Among them, the hot rolling temperature is 960 °C, the holding time is 2 h, and the rolling speed is 1.5 m / s; the rough rolling temperature is 300 °C, and the rolling speed is 3 m / s; the thick shearing temperature is 300 °C, and the shearing force is 500 kN; the annealing temperature is 550 °C, and the holding time is 3 h; the cleaning treatment includes polishing, pickling, water washing, passivation, water washing, and drying. The pickling agent is a sulfuric acid solution with a mass fraction of 18 ± 0.5%, and the passivation agent is a benzotriazole solution with a mass fraction of 0.15%.

[0054] Detect the performance of the prepared nickel-silicon-based copper alloy strip. The detection method is the same as that in Example 1, and the results are shown in Table 1.

[0055] Comparative Example 1: On the basis of Example 3, replace Zr-MOF with commercially available nano-zirconia powder in step S2, keep the other steps unchanged, and still adjust the raw material ratio so that the mass percentage composition of the nickel-silicon-based copper alloy ingot remains unchanged, and prepare a nickel-silicon-based copper alloy strip.

[0056] Detect the performance of the prepared nickel-silicon-based copper alloy strip. The detection method is the same as that in Example 1, and the results are shown in Table 1.

[0057] Comparative Example 2: On the basis of Example 3, without going through step S2 treatment, directly transfer the Zr-MOF in step S1 to a tubular furnace. Under an air atmosphere, heat it to 300 °C at a rate of 3 °C / min and hold for 4 h, then heat it to 800 °C at a rate of 5 °C / min and hold for 3 h, and cool it naturally to room temperature, grind and crush it to prepare zirconium oxide powder, and use this zirconium oxide powder to replace the nickel-plated zirconia powder in step S4, keep the other steps unchanged, and still adjust the raw material ratio so that the mass percentage composition of the nickel-silicon-based copper alloy ingot remains unchanged, and prepare a nickel-silicon-based copper alloy strip.

[0058] Detect the performance of the prepared nickel-silicon-based copper alloy strip. The detection method is the same as that in Example 1, and the results are shown in Table 1.

[0059] Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Average grain size / μm 13 15 15 19 23 Tensile strength / MPa 658 673 687 602 589 Conductivity / %IACS 62.4 61.5 61.1 56.8 54.5 Anti-softening temperature / °C 570 580 580 560 520 Thermal conductivity / W / (m·K) 360.22 358.51 357.64 352.6 340.93 Bending property The surface is smooth, the color and luster are evenly matte, without cracks and orange peel The surface is smooth, the color and luster are evenly matte, without cracks and orange peel The surface is smooth, the color and luster are evenly matte, without cracks and orange peel The surface is relatively smooth, with a small amount of orange peel The surface is rough, with cracks and orange peel <![CDATA[Number of oxygen evolution phase particles / piece / μm 2 > 2.8 3.1 3.0 2.2 2.0

[0060] As can be seen from Table 1, the nickel-silicon-based copper alloy strips in Examples 1 - 3 have uniform apparent color and luster, are in a matte state, and still do not show cracks and orange peel after the 90° bending test, have good mechanical properties, and have high electrical conductivity and thermal conductivity.

[0061] In Comparative Example 1, the grain coarsening may be due to the lack of a porous structure in the commercially available nano-zirconia powder, resulting in a reduced pinning effect, a decline in mechanical properties, and an increase in grain size due to grain boundary migration during the annealing process; moreover, the decrease in its electrical conductivity and thermal conductivity may be because its particles are relatively large, hindering the electron transport and heat conduction paths. In Comparative Example 2, the performance degradation is due to the lack of the wetting effect of the nickel plating layer, resulting in agglomeration of the zirconium oxide powder, a decrease in electrical conductivity and thermal conductivity, a weakening of the grain refinement effect, and stress concentration caused by the agglomerated zirconium oxide, leading to crack formation.

[0062] In Comparative Example 1 and Comparative Example 2, the number of oxygen-containing precipitated phase particles decreases, and the distribution of the zirconia phase is uneven. The agglomerated zirconia is counted as a single particle, resulting in a decrease in the value.

[0063] It should be noted that in this article, terms such as "including", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article, or device.

[0064] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A preparation method of a nickel-silicon-based copper alloy strip for integrated circuits, the preparation method comprising: The nickel-silicon-based copper alloy ingot is subjected to sawing, hot rolling for blooming, surface milling, rough rolling, thick shearing, annealing and cleaning treatments. It is characterized in that the nickel-silicon-based copper alloy ingot is prepared through the following steps: Step 1: Nickel hydroxide precipitate is formed in Zr-MOF by nickel nitrate and ammonia water, and then calcined in an air atmosphere to obtain zirconium-nickel composite oxide powder, which is then subjected to reduction treatment to obtain nickel-plated zirconia powder; Step 2: Add metallic nickel and copper-magnesium alloy into a vacuum melting furnace, evacuate to 10 Pa, heat to complete melting at 1300 - 1350 °C, add a refining agent accounting for 0.12 - 0.15% of the melt mass and continue refining for 20 - 30 min. After slag removal, add copper-silicon alloy, copper-lanthanum alloy and copper-magnesium alloy under argon protection, and continue melting for 10 - 15 min. Keep the nickel-plated zirconia powder under argon protection and at 300 - 350 °C for 20 - 30 min, then inject the degassed nickel-plated zirconia powder into the melt by argon carrier gas injection method, continue melting for 30 - 40 min, ultrasonic at a frequency of 30 - 40 kHz for 3 - 5 min, and then cast the melt into shape by vertical continuous casting and spray cooling with a spray ring to obtain a nickel-silicon-based copper alloy ingot; The specific preparation steps of the zirconium-nickel composite oxide powder are as follows: Transfer Zr-MOF and 10 wt% nickel nitrate solution to a reaction kettle, stir at 200 - 500 r / min for 10 - 20 min, ultrasonically disperse for 5 - 10 min, adjust the pH value to 7.5 - 8.5 with ammonia water, vacuum impregnate at 50 - 60 °C and 0.05 - 0.08 MPa for 1 - 2 h, stand at room temperature for aging for 6 - 8 h, centrifuge and filter, vacuum dry the precipitate to constant weight, then transfer it to a tube furnace, in an air atmosphere, heat to 250 - 300 °C at a rate of 2 - 3 °C / min and hold for 2 - 4 h, heat to 700 - 800 °C at a rate of 4 - 5 °C / min and hold for 2 - 3 h, naturally cool to room temperature, grind and crush to obtain zirconium-nickel composite oxide powder; The dosage ratio of the Zr-MOF to the nickel nitrate solution is 1 g : 5 - 10 mL.

2. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 1, wherein The ingot discharging temperature at the lower part of the mold for the vertical continuous casting is 600 - 800 °C.

3. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 1, characterized in that, The refining agent is composed of borax and phosphor copper mixed in a mass ratio of 5 :

1.

4. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 1, characterized in that, The specific preparation steps of the nickel-plated zirconia powder are as follows: Transfer the zirconium-nickel composite oxide powder to a tube furnace, keep it under a hydrogen atmosphere and at 500 - 600 °C for 1 - 2 h, naturally cool to room temperature, grind and crush to obtain nickel-plated zirconia powder.

5. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 1, characterized in that, The Zr-MOF is prepared through the following steps:

6. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 5, characterized in that, Add zirconium chloride, terephthalic acid and N,N-dimethylformamide into a reaction kettle and stir and mix them, stir and react at 140 - 160 °C and 200 - 300 r / min for 10 - 12 h, naturally cool to room temperature, centrifuge and filter, wash the precipitate with anhydrous ethanol and deionized water respectively for 2 - 3 times, vacuum dry to constant weight to obtain Zr-MOF. The mass ratio of the zirconium chloride, terephthalic acid and N,N-dimethylformamide is 2 - 2.33 : 1.4 - 1.66 : 300 - 360.

7. The preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to claim 1, characterized in that, The mass percentage composition of the nickel-silicon-based copper alloy ingot is: Ni 2-3%, Si 0.2-0.4%, La 0.05-0.09%, Zr 0.05-0.06%, Mg 0.02-0.04%, and the balance is Cu and inevitable impurities.

8. A nickel-silicon-based copper alloy strip for integrated circuits, characterized in that, It is obtained by the preparation method of a nickel-silicon-based copper alloy strip for integrated circuits according to any one of claims 1-7.