Corrosion-resistant copper alloy material for electronics and process for producing the same

Abstract

The present application relates to the technical field of copper alloy, in particular to a kind of electronic corrosion-resistant copper alloy material and its preparation process.A kind of electronic corrosion-resistant copper alloy material preparation process, comprising: preparation base copper alloy;Surface treatment;Preparation copper alloy material.The present application is by adding hafnium boride powder and molybdenum carbide powder into CuCrZr base powder, after sintering, solid solution treatment and aging treatment, the base copper alloy is made, hafnium boride and molybdenum carbide are dispersed in copper matrix, can multi-scale hinder dislocation movement, synergistically improve the tensile strength of base copper alloy, on the other hand, hafnium boride and molybdenum carbide can pin the grain boundary and subgrain boundary, effectively inhibit grain growth and recrystallization process, make alloy keep strength at higher temperature, can in wider temperature range temperature microstructure, prevent softening, to synergistically improve the high-temperature softening temperature of base copper alloy.

Description

Technical Field

[0001] This invention relates to the field of copper alloy technology, specifically to a corrosion-resistant copper alloy material for electronic applications and its preparation process. Background Technology

[0002] In the field of integrated circuit packaging, the lead frame, as a core component of semiconductor packaging, undertakes the functions of electrical signal transmission, heat dissipation, and mechanical support between the chip and external circuits. Its performance directly determines the reliability, stability, and lifespan of semiconductor devices. With the rapid development of the semiconductor industry towards high density, high power, and miniaturization, and with increasingly stringent requirements for the service environment of devices in applications such as automotive electronics, industrial control, and aerospace, lead frame materials must simultaneously meet the comprehensive requirements of high electrical and thermal conductivity, excellent corrosion resistance, good mechanical properties, and processability.

[0003] Traditional lead frames made of copper alloys, while possessing high electrical and thermal conductivity, are prone to oxide film formation, pitting corrosion, or intergranular corrosion on their surface under humid and hot environments, acidic and alkaline media, or during long-term service. This leads to increased contact resistance, signal transmission distortion, and in severe cases, plating peeling and encapsulation failure. To improve corrosion resistance, existing technologies often employ surface electroplating of metal coatings. However, the coating and substrate have insufficient adhesion and are prone to peeling, which can easily affect the overall conductivity of the material. In addition, the high-temperature process during encapsulation also requires copper alloy materials to have excellent resistance to softening to prevent deformation and performance degradation.

[0004] Therefore, there is a need to propose a corrosion-resistant copper alloy material for electronics with high mechanical properties and resistance to high-temperature softening, as well as its preparation process, in order to extend its service life. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a corrosion-resistant copper alloy material for electronic applications and its preparation process.

[0006] This invention provides a process for preparing a corrosion-resistant copper alloy material for electronic applications, comprising the following steps: S1: Preparation of base copper alloy S1.1: Place electrolytic copper in a vacuum induction furnace, heat it to 1250-1350℃ under argon protection, add chromium powder, stir and melt for 10-20 minutes, then adjust the heating temperature to 1200-1250℃, add zirconium powder, and continue stirring and melting for 5-10 minutes to obtain a mixed melt. S1.2: The above-mentioned mixed melt is kept at 1180-1220℃ for gas atomization, and the powder is collected, then sieved and vacuum dried to obtain the matrix powder; S1.3: Mix the above matrix powder with hafnium boride powder and molybdenum dicarbide powder, then add anhydrous ethanol, mix in a mixer at 60-80 rpm for 4-6 hours, then vacuum dry at 60-80℃ for 10-12 hours, and after sieving, obtain composite powder. S1.4: The above composite powder is loaded into a graphite mold and then placed in a vacuum hot press furnace. The temperature is first raised to 300-400℃ at 5℃ / min, while applying 10-15MPa, and sintered at this temperature for 30-40min. Then the temperature is raised to 900-950℃ at 10℃ / min, while applying 30-40MPa, and sintered at this temperature for 1-2h. The pressure is then maintained and the furnace is cooled to room temperature to obtain a sintered green body. S1.5: The above sintered billet is heated to 900-950℃ under argon protection and held for 80-90 min. Then it is water quenched at a cooling rate of 500℃ / s. Then it is held at 450-500℃ for 2-3 h under argon protection. After being cooled to room temperature in the furnace, the base copper alloy is obtained. S2: Surface treatment After degreasing and pickling, the above-mentioned base copper alloy is subjected to laser microstructuring and plasma treatment in sequence to obtain a surface-treated base copper alloy. S3: Preparation of copper alloy materials The copper alloy substrate with the above surface treatment is activated by acid and then electroplated in a composite electroplating solution to form a composite coating. After heat treatment, the copper alloy material is obtained.

[0007] Furthermore, S2 specifically includes the following steps: S2.1: Immerse the base copper alloy obtained in step S1.5 into the degreasing solution, ultrasonically treat it at 60-70℃ for 10-15 minutes, then immerse it in the pickling solution for 20-30 seconds. After taking it out, ultrasonically clean it with deionized water, soak it in anhydrous ethanol for dehydration, and vacuum dry it to obtain the pretreated base copper alloy. S2.2: Fix the pretreated copper alloy substrate above on a laser processing platform. Under argon protection, perform laser microstructuring treatment using a unidirectional scanning and multi-pass superposition mode according to preset parameters. After cooling, rinse the surface with deionized water and then vacuum dry at 60-80℃ for 1-2 hours to obtain the laser microstructuring copper alloy substrate. S2.3: The above-mentioned laser-microstructured substrate copper alloy is placed in a plasma reaction chamber, argon and hydrogen are introduced, and plasma treatment is carried out at 100-150W and 50-60℃ for 20-30 minutes to obtain a surface-treated substrate copper alloy.

[0008] Furthermore, S3 specifically includes the following steps: S3.1: Immerse the surface-treated copper alloy substrate obtained in step S2.3 into a 5-10 vol% dilute sulfuric acid solution for 30-40 seconds, then remove it to obtain an activated copper alloy substrate. S3.2: Place the above-mentioned activated copper alloy substrate into a composite electroplating solution, at a concentration of 1-2 A / dm³. 2 Pulse electroplating at 45-55℃ and 50-100Hz for 40-50 minutes forms a composite coating. After removal, it is washed with deionized water and vacuum dried to obtain a copper alloy composite electroplating layer. S3.3: The above-mentioned composite electroplated copper alloy is heated to 300-350℃ under argon protection and held at that temperature for 1-2 hours. After being cooled to room temperature in the furnace, the copper alloy material is obtained.

[0009] Furthermore, by mass percentage, the raw material composition of the base copper alloy is: 1-3% chromium, 0.2-0.3% zirconium, 1.8-2.2% hafnium boride, 3.2-4.6% molybdenum dicarbide, with the balance being copper.

[0010] Furthermore, the degreasing solution includes: 50-80 g / L sodium hydroxide, 20-30 g / L sodium carbonate, 10-15 g / L sodium phosphate, with the remainder being deionized water.

[0011] Furthermore, the pickling solution comprises: 5-8 vol% nitric acid and 2-3 vol% hydrofluoric acid, with the balance being deionized water.

[0012] Furthermore, the laser microstructuring processing parameters are as follows: laser type is pulsed fiber laser, wavelength is 1064 nm, pulse width is 10-50 ns, and energy density is 8-12 J / cm². 2 The spot diameter is 20-30μm.

[0013] Furthermore, the volume ratio of argon to hydrogen is 4:1.

[0014] Furthermore, the composite electroplating solution comprises: 20-30 g / L copper sulfate, 50-70 g / L nickel sulfate, 10-20 g / L sodium stannate, 1.2-1.6 g / L graphene, 0.1-0.2 g / L sodium saccharin, 0.1-0.2 g / L cetyltrimethylammonium bromide, 80-120 g / L sodium citrate, 15-25 g / L boric acid, with the balance being deionized water.

[0015] A corrosion-resistant copper alloy material for electronic applications, prepared by the preparation process of a corrosion-resistant copper alloy material for electronic applications described in any one of the above claims.

[0016] The present invention has the following advantages: 1. In this invention, by adding hafnium boride powder and molybdenum dicarbide powder to CuCrZr matrix powder, and then preparing a matrix copper alloy through sintering, solution treatment, and aging treatment, on the one hand, because hafnium boride and molybdenum dicarbide have different size distributions, after being dispersed in the copper matrix, they can hinder dislocation movement at multiple scales, and work together to make the strengthening effect more uniform and lasting, thereby synergistically improving the tensile strength of the matrix copper alloy. On the other hand, because hafnium boride and molybdenum dicarbide have high melting points, they can pin grain boundaries and subgrain boundaries, effectively inhibiting grain growth and recrystallization processes, allowing the alloy to maintain strength at higher temperatures. After the two are combined, the microstructure can be adjusted over a wider temperature range to prevent softening, thereby synergistically improving the high-temperature softening temperature of the matrix copper alloy.

[0017] 2. In this invention, after the surface-treated copper alloy substrate is activated by acid leaching, it is then placed in a composite electroplating solution for electroplating to deposit a graphene-CuNiSn composite coating on the surface of the copper alloy substrate. Since the graphene is uniformly dispersed in the CuNiSn alloy, it can construct a three-dimensional conductive fiber network, providing low-resistance channels for high-resistance regions at grain boundaries, thereby reducing the overall resistivity of the coating and improving its conductivity. In addition, graphene becomes a heterogeneous nucleation site during the electroplating process, promoting the nucleation of CuNiSn grains, refining the grains of the coating, making the microstructure of the coating more uniform and dense, and promoting the formation of a more stable passivation film in the CuNiSn alloy, reducing the channels for corrosive media penetration, thereby improving the corrosion resistance of the copper alloy material.

[0018] 3. In this invention, before electroplating, the base copper alloy is first subjected to laser structuring treatment, which creates specific micro-geometric shapes on the surface of the base copper alloy by pulsed laser, thereby increasing the surface roughness of the base copper alloy and increasing the contact area. During electroplating, the coating will completely fill the microstructure. After cooling, a "mortise and tenon" mechanical interlocking is formed. Then, plasma composite activation is performed to remove the metal spatter, ceramic debris and oxide residue at the bottom of the microstructure remaining after laser processing, eliminate the obstacle of the oxide film to chemical bonding, and form a large number of unsaturated active sites on the surface of the base. These sites can form metallic bonds or coordination bonds with Cu, Ni and Sn atoms in the coating, achieving synergistic effect of macroscopic mechanical interlocking and nanoscale chemical bonding, thereby effectively improving the bonding force between the base copper alloy and the composite coating. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the preparation process of the corrosion-resistant copper alloy material for electronic applications used in embodiments of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention.

[0021] Example 1: A preparation process for a corrosion-resistant copper alloy material for electronic applications, such as... Figure 1 As shown, it includes the following steps: S1: Preparation of base copper alloy S1.1: Place electrolytic copper in a vacuum induction furnace, heat it to 1250°C under argon protection, add chromium powder, stir and melt for 10 minutes, then adjust the heating temperature to 1200°C, add zirconium powder, and continue stirring and melting for 5 minutes to obtain a mixed melt. S1.2: The above-mentioned mixed melt is kept at 1180°C for gas atomization, and the powder is collected, then sieved and vacuum dried to obtain the matrix powder; S1.3: Mix the above matrix powder with hafnium boride powder and molybdenum dicarbide powder, then add anhydrous ethanol, mix in a mixer at 60 rpm for 4 h, then vacuum dry at 60 °C for 10 h, and after sieving, obtain composite powder; S1.4: The above composite powder is loaded into a graphite mold and then placed in a vacuum hot press furnace. The temperature is first raised to 300°C at 5°C / min, and 10MPa is applied at the same time. The temperature is held for sintering for 30 min. Then the temperature is raised to 900°C at 10°C / min, and 30MPa is applied at the same time. The temperature is held for sintering for 1 h. The pressure is then maintained and the furnace is cooled to room temperature to obtain a sintered green body. S1.5: The above sintered billet is heated to 900℃ under argon protection and held for 80 min. Then it is water quenched at a cooling rate of 500℃ / s. Then it is held at 450℃ for 2 h under argon protection. After being cooled to room temperature in the furnace, a base copper alloy is obtained. The raw material composition of the base copper alloy by mass percentage is: 1% chromium, 0.2% zirconium, 1.8% hafnium boride, 3.2% molybdenum dicarbide, and the balance is copper. S2: Surface treatment S2.1: Immerse the base copper alloy obtained in step S1.5 in a degreasing solution, ultrasonically treat it at 60°C for 10 minutes, then immerse it in an acid pickling solution for 20 seconds. After removal, ultrasonically clean it with deionized water, dehydrate it by soaking it in anhydrous ethanol, and vacuum dry it to obtain a pretreated base copper alloy. The degreasing solution includes: 50 g / L sodium hydroxide, 20 g / L sodium carbonate, 10 g / L sodium phosphate, with the remainder being deionized water. The acid pickling solution includes: 5 vol% nitric acid and 2 vol% hydrofluoric acid, with the remainder being deionized water. S2.2: The pretreated copper alloy substrate is fixed on a laser processing platform and, under argon protection, a pulsed fiber laser with a wavelength of 1064 nm, a pulse width of 10 ns, and an energy density of 8 J / cm² is used. 2 The laser microstructured substrate copper alloy with a spot diameter of 20 μm was obtained by using a unidirectional scanning and multi-channel superposition mode. After cooling, the surface was rinsed with deionized water and then vacuum dried at 60℃ for 1 h. S2.3: The above-mentioned laser-microstructured substrate copper alloy is placed in a plasma reaction chamber, and argon and hydrogen gas with a volume ratio of 4:1 are introduced. The mixture is then treated with plasma at 100W and 50℃ for 20 minutes to obtain a surface-treated substrate copper alloy. S3: Preparation of copper alloy materials S3.1: Immerse the surface-treated copper alloy substrate obtained in step S2.3 into a 5 vol% dilute sulfuric acid solution for 30 seconds, then remove it to obtain an activated copper alloy substrate. S3.2: Dissolve sodium citrate and boric acid in 4 / 5 of deionized water, then add copper sulfate and nickel sulfate while stirring. After thorough dissolution, obtain the main solution. Next, dissolve sodium stannate in the remaining deionized water heated to 40°C, then pour it into the main solution. After mixing, add hexadecyltrimethylammonium bromide and stir until completely dissolved. Add graphene powder and ultrasonically disperse for 30 minutes to obtain the composite electroplating solution. Place the activated copper alloy substrate into the composite electroplating solution at 1 A / dm³. 2 The composite plating layer was formed by pulse electroplating at 45℃ and 50Hz for 40 minutes. After removal, it was washed with deionized water and vacuum dried to obtain a composite electroplated copper alloy. The composite electroplating solution included: 20g / L copper sulfate, 50g / L nickel sulfate, 10g / L sodium stannate, 1.2g / L graphene, 0.1g / L sodium saccharin, 0.1g / L hexadecyltrimethylammonium bromide, 80g / L sodium citrate, 15g / L boric acid, and the balance being deionized water. S3.3: The above-mentioned composite electroplated copper alloy is heated to 300°C under argon protection and held at that temperature for 1 hour. After being cooled to room temperature in the furnace, the copper alloy material is obtained.

[0022] Example 2: A preparation process for a corrosion-resistant copper alloy material for electronic applications, such as... Figure 1 As shown, it includes the following steps: S1: Preparation of base copper alloy S1.1: Place electrolytic copper in a vacuum induction furnace, heat it to 1300℃ under argon protection, add chromium powder, stir and melt for 15 minutes, then adjust the heating temperature to 1225℃, add zirconium powder, and continue stirring and melting for 7.5 minutes to obtain a mixed melt. S1.2: The above-mentioned mixed melt is kept at 1200°C for gas atomization, and the powder is collected, then sieved and vacuum dried to obtain the matrix powder; S1.3: Mix the above matrix powder with hafnium boride powder and molybdenum dicarbide powder, then add anhydrous ethanol, mix at 70 rpm for 5 h in a mixer, then vacuum dry at 70 °C for 11 h, and sieve to obtain composite powder. S1.4: The above composite powder is loaded into a graphite mold and then placed in a vacuum hot press furnace. The temperature is first raised to 350°C at 5°C / min, while 12MPa is applied and the temperature is held for sintering for 35 min. Then the temperature is raised to 925°C at 10°C / min, while 35MPa is applied and the temperature is held for sintering for 1.5 h. The pressure is then maintained and the furnace is cooled to room temperature to obtain a sintered green body. S1.5: The above sintered billet is heated to 925℃ under argon protection and held for 85 min. Then it is water quenched at a cooling rate of 500℃ / s. Then it is held at 475℃ for 2.5 h under argon protection. After being cooled to room temperature in the furnace, a base copper alloy is obtained. The raw material composition of the base copper alloy by mass percentage is: 2% chromium, 0.25% zirconium, 2% hafnium boride, 3.9% molybdenum dicarbide, and the balance is copper. S2: Surface treatment S2.1: Immerse the base copper alloy obtained in step S1.5 in a degreasing solution, ultrasonically treat it at 65°C for 12.5 min, then immerse it in an acid pickling solution for 25 s. After removal, ultrasonically clean it with deionized water, dehydrate it by soaking it in anhydrous ethanol, and vacuum dry it to obtain a pretreated base copper alloy. The degreasing solution includes: 65 g / L sodium hydroxide, 25 g / L sodium carbonate, and 12.5 g / L sodium phosphate, with the remainder being deionized water. The acid pickling solution includes: 6.5 vol% nitric acid and 2.5 vol% hydrofluoric acid, with the remainder being deionized water. S2.2: The pretreated copper alloy substrate is fixed on a laser processing platform and, under argon protection, a pulsed fiber laser with a wavelength of 1064 nm, a pulse width of 30 ns, and an energy density of 10 J / cm² is used. 2 The laser microstructured substrate was obtained by using a laser spot diameter of 25 μm, employing a unidirectional scanning and multi-channel superposition mode. After cooling, the surface was rinsed with deionized water and then vacuum dried at 70°C for 1.5 h. S2.3: The above-mentioned laser-microstructured substrate copper alloy is placed in a plasma reaction chamber, and argon and hydrogen gas with a volume ratio of 4:1 are introduced. The mixture is then treated with plasma at 125W and 55℃ for 25 minutes to obtain a surface-treated substrate copper alloy. S3: Preparation of copper alloy materials S3.1: Immerse the surface-treated copper alloy substrate obtained in step S2.3 into a 7.5 vol% dilute sulfuric acid solution for 35 seconds, then remove it to obtain an activated copper alloy substrate. S3.2: Dissolve sodium citrate and boric acid in 4 / 5 of deionized water, then add copper sulfate and nickel sulfate while stirring. After thorough dissolution, obtain the main solution. Next, dissolve sodium stannate in the remaining deionized water heated to 40°C, then pour it into the main solution. After mixing, add hexadecyltrimethylammonium bromide and stir until completely dissolved. Then add graphene powder and ultrasonically disperse for 35 minutes to obtain the composite electroplating solution. Place the activated copper alloy substrate into the composite electroplating solution at 1 A / dm³. 2 The composite plating layer was formed by pulse electroplating at 50℃ and 80Hz for 45 minutes. After removal, it was washed with deionized water and vacuum dried to obtain a composite electroplated copper alloy. The composite electroplating solution included: 25g / L copper sulfate, 60g / L nickel sulfate, 15g / L sodium stannate, 1.4g / L graphene, 0.15g / L sodium saccharin, 0.15g / L hexadecyltrimethylammonium bromide, 100g / L sodium citrate, 20g / L boric acid, and the balance was deionized water. S3.3: The above-mentioned composite electroplated copper alloy is heated to 325°C under argon protection and held at that temperature for 1.5 hours. After being cooled to room temperature in the furnace, the copper alloy material is obtained.

[0023] Example 3: A preparation process for a corrosion-resistant copper alloy material for electronic applications, such as... Figure 1 As shown, it includes the following steps: S1: Preparation of base copper alloy S1.1: Place electrolytic copper in a vacuum induction furnace, heat it to 1350°C under argon protection, add chromium powder, stir and melt for 20 minutes, then adjust the heating temperature to 1250°C, add zirconium powder, and continue stirring and melting for 10 minutes to obtain a mixed melt. S1.2: The above-mentioned mixed melt is kept at 1220°C for gas atomization, and the powder is collected, then sieved and vacuum dried to obtain the matrix powder; S1.3: Mix the above matrix powder with hafnium boride powder and molybdenum dicarbide powder, then add anhydrous ethanol, mix in a mixer at 80 rpm for 6 h, then vacuum dry at 80 °C for 12 h, and after sieving, obtain composite powder; S1.4: The above composite powder is loaded into a graphite mold and then placed in a vacuum hot press furnace. The temperature is first raised to 400°C at 5°C / min, while 15MPa is applied and the temperature is held for 40 min. Then the temperature is raised to 950°C at 10°C / min, while 40MPa is applied and the temperature is held for 2 h. The pressure is then maintained and the furnace is cooled to room temperature to obtain a sintered green body. S1.5: The above sintered billet is heated to 950℃ under argon protection and held for 90 min. Then it is water quenched at a cooling rate of 500℃ / s. Then it is held at 500℃ for 3 h under argon protection. After being cooled to room temperature in the furnace, a base copper alloy is obtained. The raw material composition of the base copper alloy by mass percentage is: 3% chromium, 0.3% zirconium, 2.2% hafnium boride, 4.6% molybdenum dicarbide, and the balance is copper. S2: Surface treatment S2.1: Immerse the base copper alloy obtained in step S1.5 in a degreasing solution, ultrasonically treat it at 70°C for 15 minutes, then immerse it in a pickling solution for 30 seconds. After removal, ultrasonically clean it with deionized water, dehydrate it by soaking it in anhydrous ethanol, and vacuum dry it to obtain a pretreated base copper alloy. The degreasing solution includes: 80 g / L sodium hydroxide, 30 g / L sodium carbonate, 15 g / L sodium phosphate, and the remainder is deionized water. The pickling solution includes: 8 vol% nitric acid and 3 vol% hydrofluoric acid, and the remainder is deionized water. S2.2: The pretreated copper alloy substrate is fixed on a laser processing platform and, under argon protection, a pulsed fiber laser with a wavelength of 1064 nm, a pulse width of 50 ns, and an energy density of 12 J / cm² is used. 2 The laser microstructured substrate was obtained by using a laser spot diameter of 30 μm, employing a unidirectional scanning and multi-channel superposition mode. After cooling, the surface was rinsed with deionized water and then vacuum dried at 80℃ for 2 hours. S2.3: The above-mentioned laser-microstructured substrate copper alloy is placed in a plasma reaction chamber, and argon and hydrogen gas with a volume ratio of 4:1 are introduced. The mixture is then treated with plasma at 150W and 60℃ for 30 minutes to obtain a surface-treated substrate copper alloy. S3: Preparation of copper alloy materials S3.1: Immerse the surface-treated copper alloy substrate obtained in step S2.3 into a 10 vol% dilute sulfuric acid solution for 40 seconds, then remove it to obtain an activated copper alloy substrate. S3.2: Dissolve sodium citrate and boric acid in 4 / 5 of deionized water, then add copper sulfate and nickel sulfate while stirring. After thorough dissolution, obtain the main solution. Next, dissolve sodium stannate in the remaining deionized water heated to 40°C, then pour it into the main solution. After mixing, add hexadecyltrimethylammonium bromide and stir until completely dissolved. Then add graphene powder and ultrasonically disperse for 40 minutes to obtain the composite electroplating solution. Place the activated copper alloy substrate into the composite electroplating solution at 2 A / dm³. 2The composite plating layer was formed by pulse electroplating at 55℃ and 100Hz for 50 minutes. After removal, it was washed with deionized water and vacuum dried to obtain a composite electroplated copper alloy. The composite electroplating solution included: 30g / L copper sulfate, 70g / L nickel sulfate, 20g / L sodium stannate, 1.6g / L graphene, 0.2g / L sodium saccharin, 0.2g / L hexadecyltrimethylammonium bromide, 120g / L sodium citrate, 25g / L boric acid, and the balance being deionized water. S3.3: The above-mentioned composite electroplated copper alloy is heated to 350°C under argon protection and held at that temperature for 2 hours. After being cooled to room temperature in the furnace, the copper alloy material is obtained.

[0024] Comparative Example 1 differs from Example 1 in that the molybdenum dicarbide powder in step S1.3 is replaced with an equal amount of hafnium boride powder.

[0025] Comparative Example 2 differs from Example 1 in that the hafnium boride powder in step S1.3 is replaced with an equal amount of molybdenum dicarbide powder.

[0026] Comparative Example 3 differs from Example 1 in that steps S2 and S3 are removed.

[0027] Comparative Example 4 differs from Example 1 in that graphene is removed from the composite electroplating solution in step S3.2.

[0028] Comparative Example 5 differs from Example 1 in that step S2 is removed, i.e., electroplating is performed directly on the surface of the copper alloy substrate.

[0029] Comparative Example 6 differs from Example 1 in that step S2.3 is removed, i.e. only laser microstructuring is performed.

[0030] Comparative Example 7 differs from Example 1 in that step S2.2 is removed, i.e. only plasma treatment is performed.

[0031] Test example: Test 1: The room temperature tensile strength of the base copper alloys prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to GB / T34505-2017. The test was repeated three times and the average value was taken. The results are shown in Table 1.

[0032] Test 2: The high-temperature softening temperature of the base copper alloys prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to GB / T33370-2016. The test was repeated three times and the average value was taken. The results are shown in Table 1.

[0033] Table 1: Test results of tensile strength and high-temperature softening temperature

[0034] As shown in Table 1, in Comparative Examples 1 and 2, when only one of hafnium boride powder or molybdenum dicarbide powder was added, the tensile strength and high-temperature softening temperature of the prepared matrix copper alloy were lower than those in Example 1. It can be seen that by adding hafnium boride powder and molybdenum dicarbide powder to CuCrZr matrix powder and preparing a matrix copper alloy through sintering, solution treatment and aging treatment, not only can the tensile strength of the matrix copper alloy be synergistically improved, but the high-temperature softening temperature of the matrix copper alloy can also be synergistically improved.

[0035] Test 3: The conductivity of the copper alloy materials prepared in Examples 1-3 and Comparative Examples 3-4 was tested according to GB / T32791-2016. The test was repeated three times and the average value was taken. The results are shown in Table 2.

[0036] Test 4: The copper alloy materials prepared in Examples 1-3 and Comparative Examples 3-4 were immersed in 3.5wt% NaCl solution at room temperature for 21 days, and their corrosion rate was tested. The test was repeated three times and the average value was taken. The results are shown in Table 2.

[0037] Table 2: Test results of electrical conductivity and corrosion rate of copper alloy materials

[0038] As shown in Table 2, compared with Example 1 where a composite coating was electroplated on the surface of the copper alloy without electroplating the base copper alloy in Comparative Example 3, the corrosion rate of the copper alloy material prepared in Example 1 was significantly higher than that in Comparative Example 3, while the conductivity was not much different from that of the copper alloy in Comparative Example 3. In Comparative Example 4, after removing the graphene from the composite electroplating solution and then electroplating the base copper alloy, the corrosion rate of the copper alloy material was lower than that in Comparative Example 3, but still higher than that in Example 1, and the conductivity was significantly lower than that in Example 1. It can be seen that by activating the surface-treated base copper alloy with acid leaching and then placing it in a composite electroplating solution for electroplating, the corrosion resistance of the copper alloy material can be effectively improved, and the addition of graphene can effectively improve the conductivity of the coating.

[0039] Test 5: The bonding strength of the composite coatings of the copper alloy materials prepared in Examples 1-3 and Comparative Examples 5-7 was tested by thermal shock test according to GB / T13913—1992. First, the materials were kept at 250℃ in an electric heating drying oven for 1 hour, and then quickly placed in cold water. This process was repeated 20 times, and the results are shown in Table 3.

[0040] Table 3: Test Results of Adhesion of Composite Coating

[0041] As shown in Table 3, in Comparative Example 5, when no treatment was applied to the surface of the copper alloy substrate and the composite coating was directly electroplated, the resulting composite coating of the copper alloy material exhibited blistering and cracking after thermal shock testing. In Comparative Examples 6 and 7, when only laser microstructuring or plasma treatment was applied to the surface of the copper alloy substrate, the resulting composite coating of the copper alloy material did not crack after thermal shock testing, but blistering occurred. This indicates that laser structuring treatment of the copper alloy substrate before electroplating, followed by plasma composite activation, can effectively improve the bonding force between the copper alloy substrate and the composite coating.

[0042] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A preparation process for a corrosion-resistant copper alloy material for electronic applications, characterized in that, Includes the following steps: S1: Preparation of base copper alloy S1.1: Place electrolytic copper in a vacuum induction furnace, heat it to 1250-1350℃ under argon protection, add chromium powder, stir and melt for 10-20 minutes, then adjust the heating temperature to 1200-1250℃, add zirconium powder, and continue stirring and melting for 5-10 minutes to obtain a mixed melt. S1.2: The above-mentioned mixed melt is kept at 1180-1220℃ for gas atomization, and the powder is collected, then sieved and vacuum dried to obtain the matrix powder; S1.3: Mix the above matrix powder with hafnium boride powder and molybdenum dicarbide powder, then add anhydrous ethanol, mix in a mixer at 60-80 rpm for 4-6 hours, then vacuum dry at 60-80℃ for 10-12 hours, and after sieving, obtain composite powder. S1.4: The above composite powder is loaded into a graphite mold and then placed in a vacuum hot press furnace. The temperature is first raised to 300-400℃ at 5℃ / min, while applying 10-15MPa, and sintered at this temperature for 30-40min. Then the temperature is raised to 900-950℃ at 10℃ / min, while applying 30-40MPa, and sintered at this temperature for 1-2h. The pressure is then maintained and the furnace is cooled to room temperature to obtain a sintered green body. S1.5: The above sintered billet is heated to 900-950℃ under argon protection and held for 80-90 min. Then it is water quenched at a cooling rate of 500℃ / s. Then it is held at 450-500℃ for 2-3 h under argon protection. After being cooled to room temperature in the furnace, the base copper alloy is obtained. The raw material composition of the base copper alloy, by mass percentage, is: 1-3% chromium, 0.2-0.3% zirconium, 1.8-2.2% hafnium boride, 3.2-4.6% molybdenum dicarbide, with the balance being copper; S2: Surface treatment After degreasing and pickling, the above-mentioned base copper alloy is subjected to laser microstructuring and plasma treatment in sequence to obtain a surface-treated base copper alloy. S3: Preparation of copper alloy materials S3.1: Immerse the above-mentioned surface-treated copper alloy substrate in a 5-10 vol% dilute sulfuric acid solution for 30-40 seconds, then remove it to obtain an activated copper alloy substrate. S3.2: Place the above-mentioned activated copper alloy substrate into a composite electroplating solution, at a concentration of 1-2 A / dm³. 2 Pulse electroplating at 45-55℃ and 50-100Hz for 40-50 minutes forms a composite coating. After removal, it is washed with deionized water and vacuum dried to obtain a copper alloy composite electroplating layer. S3.3: The above-mentioned composite electroplated copper alloy is heated to 300-350℃ under argon protection and held at that temperature for 1-2 hours. After being cooled to room temperature in the furnace, the copper alloy material is obtained. The composite electroplating solution includes: 20-30 g / L copper sulfate, 50-70 g / L nickel sulfate, 10-20 g / L sodium stannate, 1.2-1.6 g / L graphene, 0.1-0.2 g / L sodium saccharin, 0.1-0.2 g / L cetyltrimethylammonium bromide, 80-120 g / L sodium citrate, 15-25 g / L boric acid, with the balance being deionized water.

2. The preparation process of a corrosion-resistant copper alloy material for electronic applications according to claim 1, characterized in that, S2 specifically includes the following steps: S2.1: Immerse the base copper alloy obtained in step S1.5 into the degreasing solution, ultrasonically treat it at 60-70℃ for 10-15 minutes, then immerse it in the pickling solution for 20-30 seconds. After taking it out, ultrasonically clean it with deionized water, soak it in anhydrous ethanol for dehydration, and vacuum dry it to obtain the pretreated base copper alloy. S2.2: Fix the pretreated copper alloy substrate above on a laser processing platform. Under argon protection, perform laser microstructuring treatment using a unidirectional scanning and multi-pass superposition mode according to preset parameters. After cooling, rinse the surface with deionized water and then vacuum dry at 60-80℃ for 1-2 hours to obtain the laser microstructuring copper alloy substrate. S2.3: The above-mentioned laser-microstructured substrate copper alloy is placed in a plasma reaction chamber, argon and hydrogen are introduced, and plasma treatment is carried out at 100-150W and 50-60℃ for 20-30 minutes to obtain a surface-treated substrate copper alloy.

3. The preparation process of a corrosion-resistant copper alloy material for electronic applications according to claim 2, characterized in that, The degreasing solution consists of 50-80 g / L sodium hydroxide, 20-30 g / L sodium carbonate, and 10-15 g / L sodium phosphate, with the remainder being deionized water.

4. The preparation process of a corrosion-resistant copper alloy material for electronic applications according to claim 2, characterized in that, The pickling solution consists of 5-8 vol% nitric acid and 2-3 vol% hydrofluoric acid, with the remainder being deionized water.

5. The preparation process of a corrosion-resistant copper alloy material for electronic applications according to claim 2, characterized in that, Laser microstructuring parameters: laser type is pulsed fiber laser, wavelength is 1064nm, pulse width is 10-50ns, and energy density is 8-12J / cm². 2 The spot diameter is 20-30μm.

6. The preparation process of a corrosion-resistant copper alloy material for electronic applications according to claim 2, characterized in that, The volume ratio of argon to hydrogen is 4:

1.

7. A corrosion-resistant copper alloy material for electronic applications, characterized in that, It is prepared by the preparation process of a corrosion-resistant copper alloy material for electronic use as described in any one of claims 1-6.

Images