Corrosion-resistant gold-plated palladium copper wire and preparation method and application thereof

Abstract

The invention belongs to the technical field of integrated circuits, and particularly relates to a corrosion-resistant gold-plated palladium copper wire and a preparation method and application thereof. The preparation method comprises the following steps: carrying out palladium pre-plating on the surface of a copper base wire by adopting a palladium pre-plating solution to form a first palladium layer; carrying out palladium plating increase on the surface of the first palladium layer by adopting a palladium plating increase solution to form a second palladium layer; gold plating is conducted on the surface of the second palladium layer through electrogilding liquid, a gold-plated layer is formed, and a semi-finished product is obtained; and performing primary annealing, wire drawing and secondary annealing on the semi-finished product, the corrosion-resistant gold-plated palladium copper wire provided by the invention has excellent bondability and corrosion resistance.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit technology, specifically relating to a corrosion-resistant gold-plated palladium-copper wire, its preparation method, and its application. Background Technology

[0002] In integrated circuit packaging, wire bonding technology dominates among various bonding technologies due to its advantages of high flexibility, ease of implementation, and low cost. In recent years, with the continuous rise in gold prices, traditional gold bonding wires have lost their cost advantage. Replacing traditional gold wires with other bonding wires to reduce packaging costs is the current development trend of bonding wires.

[0003] Gold-plated palladium copper wire refers to a copper wire with a composite coating of palladium and gold. Copper is easily oxidized in air, while palladium and gold have good oxidation resistance. The palladium layer can isolate the copper core from the air and prevent the copper from oxidizing, while the gold layer further enhances the oxidation resistance, making the gold-plated palladium copper wire less prone to oxidation during storage and use, thus extending its service life.

[0004] In the early stages of research and development, the applicant studied the processing technology of gold-plated palladium-copper wire and applied for related patents, including Chinese patents with authorization announcement numbers CN119392231B and CN116657207B. However, the CN116657207B patent only studied the electrolytic corrosion resistance of the gold-plated palladium-copper wire and did not focus on its chemical corrosion resistance. During the encapsulation process, a small amount of chlorine may be detected in the molding compound. Although chloride ions cannot directly react chemically with copper ions, Cu2O can form on the surface of copper, causing electrochemical corrosion. Furthermore, chloride ions can form complex ions with chloride ions, leading to further reactions and reducing device reliability. Therefore, providing a gold-plated palladium-copper wire with excellent chemical corrosion resistance is of great significance.

[0005] Chinese patent CN 119153426 B discloses a high corrosion-resistant and high conductivity palladium / gold palladium-copper bonding wire and its manufacturing process. This technical solution first improves the core layer. Based on this, it further improves the coating by reducing the concentration of metal ions in the electroplating solution, adding a pore-filling agent, and using pulsed current electroplating to improve the surface morphology of the electroplated coating. Annealing treatment forms a diffusion layer between the graphene copper alloy core and different electroplated layers, improving the bonding strength and performance of the bonding wire. It claims that adding graphene to the core layer significantly increases the corrosion potential of the core material and gives the copper core good heat dissipation performance and high-temperature conductivity, preventing heat accumulation and temperature rise in the bonding wire. However, it does not conduct any corrosion resistance tests. Summary of the Invention

[0006] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial solution. Specifically, the present invention provides a corrosion-resistant gold-plated palladium-copper wire, its preparation method and application, and the corrosion-resistant gold-plated palladium-copper wire provided by the present invention has excellent bonding properties and corrosion resistance.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for preparing a corrosion-resistant gold-plated palladium copper wire, comprising the following steps: pre-plating palladium on a copper baseline surface using a pre-plating palladium solution to form a first palladium layer; further plating palladium on the surface of the first palladium layer using a palladium-reinforcing solution to form a second palladium layer; plating gold on the surface of the second palladium layer using an electroplating gold solution to form a gold-plated layer, thereby obtaining a semi-finished product; and subjecting the semi-finished product to a first annealing, wire drawing, and a second annealing to obtain the final product. The pre-plating palladium solution is a chemical palladium plating solution, which includes the following raw materials: 0.001-0.1 mol / L soluble palladium salt, 0.05-1 mol / L reducing agent, 0.05-5 mol / L complexing agent, and the balance being water, with a buffer to adjust the pH to 6-8; The complexing agent comprises ethylenediamine, disodium ethylenediaminetetraacetate, and acrylic acid in a concentration ratio of 0.1-0.3:0.005-0.015:0.2-0.4.

[0008] The method for preparing corrosion-resistant gold-plated palladium copper wire provided by this invention employs a process of pre-plating palladium followed by additional palladium plating. The inventors conducted experimental research on the pre-plating palladium solution and found that when the pre-plating palladium solution is a chemical palladium plating solution, using ethylenediamine, disodium ethylenediaminetetraacetate, and acrylic acid in a concentration ratio of 0.1-0.3:0.005-0.015:0.2-0.4 as complexing agents has the following beneficial effects: First, it enables palladium ions to exist stably in the form of complexes, improving the stability of the pre-plating palladium solution; second, it improves the palladium deposition rate, facilitating the uniform deposition of palladium on the copper substrate surface, forming a dense, smooth, and glossy first palladium layer; third, the dense first palladium layer facilitates the uniform deposition of palladium in the additional palladium plating solution, thereby forming a dense second palladium layer, resulting in excellent adhesion between the palladium plating layer and the copper substrate. These beneficial effects give the gold-plated palladium copper wire excellent bonding properties and corrosion resistance.

[0009] In some preferred embodiments, before pre-plating palladium onto the copper baseline surface, the surface is sequentially treated with a 2% sodium hydroxide solution for degreasing and a 1% sulfuric acid solution for activation.

[0010] In some preferred embodiments, the soluble palladium salt is selected from at least one of palladium chloride, tetraammonium palladium sulfate, palladium nitrate, and palladium sulfate.

[0011] In some preferred embodiments, the reducing agent comprises reducing agent A and reducing agent B in a concentration ratio of 10-50:1.

[0012] In some preferred embodiments, the reducing agent A is selected from at least one of hypophosphorous acid, sodium hypophosphorous acid, and phosphorous acid.

[0013] In some preferred embodiments, the reducing agent B is selected from at least one of hydrazine, formic acid, formaldehyde, sodium formate, and potassium formate.

[0014] In some preferred embodiments, the buffer is selected from at least one of sodium dihydrogen phosphate, ammonium chloride, ammonium oxalate, and ammonium citrate.

[0015] In some preferred embodiments, when the pre-plating palladium solution is a chemical palladium solution, the pre-plating palladium process conditions are as follows: temperature 44-48℃; time 0.5-2min.

[0016] In another preferred embodiment, the pre-plating palladium solution is an electroplating palladium solution, which includes the following raw materials: 10-25 g / L of dichlorodiaminopalladium, 20-30 g / L of ammonium chloride, 35-60 g / L of ammonia, 0.5-5 g / L of additives, and the balance being water. A pH adjuster is used to adjust the pH to 6.5-8.5.

[0017] In some preferred embodiments, the additive comprises 2,5-dimercapto-1,3,4-thiadiazole, sodium polydisulfide dipropane sulfonate, and sodium perfluorononenoxybenzenesulfonate in a mass ratio of 1.5-2.5:1.5-2.5:0.002-0.004.

[0018] In some preferred embodiments, when the pre-plating palladium solution is an electroplating palladium solution, the process conditions for the pre-plating palladium are as follows: current density of 0.2-1.5 A·dm³. -2 The temperature is 20-50℃; the electroplating speed is 6-12m / min.

[0019] The pre-plating palladium solution of this invention can also be an electroplating palladium solution. However, when the pre-plating palladium solution is an electroplating palladium solution, it is necessary to control the current density for electroplating. At the same time, the inventors conducted experimental research on the electroplating palladium solution and found that when 2,5-dimercapto-1,3,4-thiadiazole, sodium polydisulfide dipropane sulfonate, and sodium perfluorononenoxybenzenesulfonate are added in a mass ratio of 1.5-2.5:1.5-2.5:0.002-0.004, not only can a dense, smooth, and glossy first palladium layer be formed, but it is also beneficial for the uniform deposition of palladium in the electroplating palladium solution on the surface of the first palladium layer, forming a second palladium layer with high bonding strength, density, low internal stress, and high coverage, making the second palladium layer bright and reducing cracks. At the same time, it is beneficial for bonding with the gold plating layer, thus further improving the corrosion resistance of the gold-plated palladium copper wire.

[0020] In some preferred embodiments, the palladium plating solution is an electroplating palladium solution.

[0021] In some preferred embodiments, the process conditions for palladium plating are as follows: current density of 1-10 A·dm. -2 The temperature is 42-46℃; the electroplating speed is 6-12m / min.

[0022] In some preferred embodiments, the electroplating gold solution comprises the following raw materials: potassium gold citrate 6-12 g / L, potassium carbonate 40-60 g / L, dodecylpyridine hydrochloride 0.4-1 g / L, pyridine sulfonic acid 0.3-0.8 g / L, triethanolamine 0.2-0.5 g / L, with the balance being deionized water, and a pH adjuster adjusting the pH to 5.5-6.5.

[0023] In some preferred embodiments, the pH adjuster in the palladium plating solution and the gold plating solution is selected from at least one of hydrochloric acid and ammonia.

[0024] In some preferred embodiments, the gold plating process conditions are as follows: the plating current is 10-50mA, and the plating speed is 5-30m / s.

[0025] Palladium-plated copper wire can avoid oxidation of the copper core, but when the temperature exceeds 400℃, the palladium layer may oxidize if environmental factors fluctuate. The temperature during the ball-forming process is much higher than 400℃, and if the protective atmosphere fluctuates, palladium oxidation may occur, leading to abnormal ball-forming or welding. This invention flash-plats a thin layer of gold on the outside of the palladium layer. Due to the inertness of gold to air, the influence of external environmental fluctuations is minimized, thereby improving the stability and consistency of the gold-plated palladium-copper wire. After plating with thin gold, the surface hardness is also reduced, the die is less damaged during the wire drawing process, and the surface quality of the plating can be better controlled.

[0026] In some preferred embodiments, the thickness of the first palladium layer is 10-20 nm.

[0027] In some preferred embodiments, the thickness of the second palladium layer is 100-110 nm.

[0028] In some preferred embodiments, the thickness of the gold plating layer is 1-3 nm.

[0029] In some preferred embodiments, the atmosphere for the first annealing is nitrogen and hydrogen in a volume ratio of 95:5, the temperature is 400-650°C, and the speed is 45-60 m / min.

[0030] In some preferred embodiments, the diameter of the copper baseline is 50-100µm.

[0031] In some preferred embodiments, the wire drawing is performed using a non-slip wire drawing machine.

[0032] In some preferred embodiments, the wire drawing speed is 80-100 m / min.

[0033] In some preferred embodiments, the diameter of the semi-finished product after drawing is 18-22µm.

[0034] In this invention, the gold-plated palladium-copper wire has an external coating, and the quality of the wire is crucially determined by the post-plating drawing process. The inventors discovered that using a roller wire drawing machine, which is a sliding type, causes wear and damage to the nanoscale coating due to the friction between the roller surface and the wire during the sliding process. This damage results in abnormal FAB (free air ball) spherical shapes during bonding operations, failing to meet customer requirements. Therefore, this invention employs a non-sliding wire drawing machine. Furthermore, it was found that controlling the drawing speed to 80-100 m / min improves the corrosion resistance of the gold-plated palladium-copper wire while preventing scratches on the surface.

[0035] In some preferred embodiments, the atmosphere for the second annealing is nitrogen, the temperature is 350-550°C, and the speed is 47-100 m / min.

[0036] Secondly, the present invention provides a corrosion-resistant gold-plated palladium-copper wire prepared by the above-described preparation method.

[0037] Thirdly, the present invention provides the application of the above-mentioned corrosion-resistant gold-plated palladium copper wire in integrated circuit packaging.

[0038] Compared with the prior art, the present invention has the following beneficial effects: 1. The method for preparing corrosion-resistant gold-plated palladium copper wire provided by the present invention first adopts a process of pre-plating palladium and then adding palladium plating. When the pre-plating palladium solution is a chemical palladium plating solution, ethylenediamine, disodium ethylenediaminetetraacetate and acrylic acid with a concentration ratio of 0.1-0.3:0.005-0.015:0.2-0.4 are used as complexing agents, which makes the gold-plated palladium copper wire have excellent bonding properties and corrosion resistance.

[0039] 2. In this invention, the corrosion resistance of the gold-plated palladium copper wire is further improved by adding 2,5-dimercapto-1,3,4-thiadiazole, sodium polydisulfide dipropane sulfonate, and sodium perfluorononenoxybenzenesulfonate in a mass ratio of 1.5-2.5:1.5-2.5:0.002-0.004 to the electroplating palladium solution used as a pre-plating palladium solution.

[0040] 3. In this invention, controlling the wire drawing speed to 80-100m / min improves the corrosion resistance of the gold-plated palladium copper wire while avoiding scratches on the surface of the wire.

[0041] 4. In this invention, controlling the thickness of the gold plating layer to 1-3nm avoids abnormal ball burning. Attached Figure Description

[0042] Figure 1 The morphology of the sintered ball of the gold-plated palladium-copper wire in Example 1; Figure 2 The morphology of the sintered ball of the gold-plated palladium-copper wire in Example 2; Figure 3 The morphology of the sintered ball of the gold-plated palladium-copper wire in Comparative Example 5-1; Figure 4 The morphology of the sintered ball of the gold-plated palladium-copper wire in Comparative Example 5-2; Figure 5 The morphology of the sintered ball of the gold-plated palladium-copper wire in Comparative Example 5-3; Figure 6 The images show the surface appearance of the gold-plated palladium-copper wires in Example 1, Comparative Example 4-1, and Comparative Example 4-2; A represents Example 1; B represents Comparative Example 4-1; and C represents Comparative Example 4-2. Figure 7 SEM images of gold-plated palladium-copper wires for Example 1, Comparative Example 4-1, and Comparative Example 4-2; A is Example 1; B is Comparative Example 4-1; C is Comparative Example 4-2; Figure 8 The morphology of the gold-plated palladium-copper wire ball after etching in Example 1 is shown. Figure 9 The morphology of the gold-plated palladium-copper wire ball after etching in Example 2 is shown. Figure 10 The morphology of the gold-plated palladium-copper wire ball after etching in Comparative Example 1 is shown. Figure 11 The morphology of the gold-plated palladium-copper wire balls after etching in Comparative Examples 2-3 is shown. Figure 12 The morphology of the gold-plated palladium-copper wire ball after etching in Comparative Example 3-1 is shown. Figure 13 The morphology of the gold-plated palladium-copper wire ball after etching in Comparative Example 4-1 is shown. Figure 14 The morphology of the gold-plated palladium-copper wire ball after etching in Comparative Example 4-2 is shown. Figure 15 The morphology of the gold-plated palladium-copper wire balls after etching in different batches of Example 1 is shown. Figure 16 The morphology of the gold-plated palladium-copper wire balls after etching in different batches of Example 1 is shown. Figure 17 The morphology of the gold-plated palladium-copper wire balls after etching in different batches of Example 1 is shown. Figure 18The morphology of the gold-plated palladium-copper wire of Example 1 after sintering is shown under the conditions of sintering current of 60mA and sintering time of 275us. Figure 19 The morphology of the gold-plated palladium-copper wire of Example 1 after sintering is shown under the conditions of sintering current of 70mA and sintering time of 220us. Detailed Implementation

[0043] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0044] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0045] Example 1 A corrosion-resistant gold-plated palladium-copper wire and its preparation method: S1. The copper baseline (diameter 58.72 μm) was degreased with a 2% sodium hydroxide solution and activated with a 1% sulfuric acid solution.

[0046] S2. Pre-plating palladium with a pre-plating palladium solution on the activated copper baseline surface to form a first palladium layer (15nm thick); then, using a palladium-enhancing solution, further plating palladium onto the first palladium layer to form a second palladium layer (100nm thick); finally, using an electroplating gold solution, plating gold onto the second palladium layer to form a gold plating layer (2.73nm thick), obtaining a semi-finished product; the semi-finished product is then subjected to a first annealing, wire drawing (20μm diameter), and a second annealing to obtain the final product; The pre-plating palladium solution is a chemical palladium plating solution. The raw material composition of the chemical palladium plating solution is: 0.05 mol / L palladium chloride, 0.07 mol / L reducing agent, 3 mol / L complexing agent, and the balance is water. Ammonium chloride is used to adjust the pH to 8. The complexing agent is ethylenediamine, disodium ethylenediaminetetraacetate, and acrylic acid in a concentration ratio of 0.2:0.01:0.3.

[0047] The reducing agent is hypophosphorous acid and formic acid in a concentration ratio of 10:1.

[0048] The pre-plating palladium process conditions are as follows: temperature 45℃; time 1 min.

[0049] The palladium plating solution is an electroplating palladium solution. The raw material composition of the electroplating palladium solution is: 20 g / L dichlorodiaminopalladium, 25 g / L ammonium chloride, 45 g / L ammonia water, 2.003 g / L additives, and the balance is water. The pH is adjusted to 7.5 with hydrochloric acid.

[0050] The additives are 2,5-dimercapto-1,3,4-thiadiazole, sodium polydisulfide dipropane sulfonate, and sodium perfluorononenoxybenzenesulfonate in a mass ratio of 2:2:0.003.

[0051] The process conditions for palladium plating are as follows: current density is 5 A·dm³. -2 The temperature was 45℃; the electroplating speed was 8m / min.

[0052] The electroplating gold solution comprises the following raw materials: 8 g / L potassium citrate, 50 g / L potassium carbonate, 0.7 g / L dodecylpyridine hydrochloride, 0.6 g / L pyridine sulfonic acid, 0.3 g / L triethanolamine, with the balance being deionized water, and the pH adjusted to 6 with ammonia.

[0053] The gold plating process conditions are as follows: the electroplating current is 40mA and the electroplating speed is 20m / s.

[0054] The atmosphere for the first annealing was nitrogen and hydrogen in a volume ratio of 95:5, at a temperature of 550°C, and at a speed of 50 m / min. The wire drawing is performed using a non-slip wire drawing machine at a speed of 100 m / min.

[0055] The second annealing was performed in a nitrogen atmosphere at a temperature of 400°C and a speed of 80 m / min.

[0056] Example 2 The only difference from Example 1 is that the pre-plating palladium solution is an electroplating palladium solution, and the raw material composition is: 20 g / L dichlorodiaminopalladium, 25 g / L ammonium chloride, 45 g / L ammonia water, 2.003 g / L additives, with the balance being water, and the pH is adjusted to 7.5 with hydrochloric acid; all other components are the same.

[0057] The pre-plating palladium process conditions are as follows: current density is 1 A·dm³. -2 The temperature was 40℃; the electroplating speed was 8m / min.

[0058] Comparative Example 1 The only difference from Example 1 is that the preparation method of the corrosion-resistant gold-plated palladium copper wire is as follows: palladium is plated on the surface of the copper wire using a palladium plating solution to obtain a palladium layer; gold is plated on the surface of the palladium layer using an electroplating gold solution to obtain a semi-finished product; the semi-finished product is subjected to a first annealing, wire drawing and a second annealing to obtain the final product; the rest are the same.

[0059] Comparative Example 2 Comparative Example 2-1 The only difference from Example 1 is that the complexing agent is ethylenediamine and acrylic acid in a concentration ratio of 0.2:0.25; all other aspects are the same.

[0060] Comparative Example 2-2 The only difference from Example 1 is that the complexing agent is disodium ethylenediaminetetraacetate and acrylic acid in a concentration ratio of 0.1:0.5; all other aspects are the same.

[0061] Comparative Examples 2-3 The only difference from Example 1 is that the complexing agent is ethylenediamine, disodium ethylenediaminetetraacetate, and acrylic acid in a concentration ratio of 0.01:0.2:0.3.

[0062] Comparative Example 3 Comparative Example 3-1 The only difference from Example 1 is that 2,5-dimercapto-1,3,4-thiadiazole is replaced with an equal mass of pyridinesulfonic acid; all other aspects are the same.

[0063] Comparative Example 3-2 The only difference from Example 1 is that the additives are 2,5-dimercapto-1,3,4-thiadiazole and sodium polydithiodipropanesulfonate in a mass ratio of 2:2; all other aspects are the same.

[0064] Comparative Example 3-3 The only difference from Example 1 is that the additives are 2,5-dimercapto-1,3,4-thiadiazole and sodium perfluorononenoxybenzenesulfonate in a mass ratio of 4:0.003; all other aspects are the same.

[0065] Comparative Example 4 Comparative Example 4-1 The only difference from Example 1 is that the wire drawing speed is 200 m / min; all other aspects are the same.

[0066] Comparative Example 4-2 The only difference from Example 1 is that the wire drawing speed is 300m / min; all other aspects are the same.

[0067] Comparative Example 5 Comparative Example 5-1 The only difference from Example 1 is that the gold plating layer thickness is 3.54 nm; everything else is the same.

[0068] Comparative Example 5-2 The only difference from Example 1 is that the gold plating layer thickness is 4.09 nm; all other aspects are the same.

[0069] Comparative Example 5-3 The only difference from Example 1 is that the gold plating layer thickness is 5.45 nm; all other aspects are the same.

[0070] Test Example 1 The gold-plated palladium-copper wires of Examples 1-2 and Comparative Examples 1-3 were subjected to a relative bending-straightening test repeated 50 times. The bending point formed a semicircle with a diameter of 1 cm. After the test, the appearance of the plating was checked, and the results are shown in Table 1.

[0071] Test Example 2 Ball bonding tests were conducted on aluminum pads using gold-plated palladium-copper wires from Examples 1-2, Comparative Example 1, Comparative Example 2 (Comparative Example 2-1-Comparative Example 2-3), and Comparative Example 3 (Comparative Example 3-1-Comparative Example 3-3), respectively. Nitrogen and hydrogen in a volume ratio of 95:9 were used as protective gases during the bonding process. The protective gas flow rate was 0.4 L / min, the contact pressure was 85 g, the bonding pressure was 45 g, and the bonding time was 9 ms. The thrust after bonding was then tested using a bonding thrust tester. The results are shown in Table 1.

[0072] Table 1

[0073] As shown in Table 1, the gold-plated palladium-copper wires of Examples 1 and 2 have smooth and bright surfaces, and the plating layer shows no cracks or peeling after bending, exhibiting high thrust. However, in Comparative Example 1, due to direct palladium plating, the surface of the resulting gold-plated palladium-copper wire is uneven, the plating layer peels off after bending, and the thrust is reduced. In Comparative Example 2 (Comparative Example 2-1-Comparative Example 2-3), due to changes in the complexing agent composition in the chemical palladium plating solution, the resulting gold-plated palladium-copper wire cannot simultaneously achieve a smooth and bright appearance, and cracks appear in the plating layer after bending, resulting in reduced thrust. In Comparative Example 3 (Comparative Example 3-1-Comparative Example 3-3), due to changes in the additive composition in the electroplating palladium solution, the resulting gold-plated palladium-copper wire cannot simultaneously achieve a smooth and bright appearance, and cracks appear in the plating layer after bending, resulting in reduced thrust.

[0074] Test Example 3 Gold-plated palladium-copper wires obtained in Examples 1-2 and Comparative Example 5 (Comparative Example 5-1-Comparative Example 5-3) were used for ball-making. The ball-making current was 50 mA and the ball-making time was 340 μs. The morphology of the ball-making is as follows. Figures 1-5 As shown.

[0075] Depend on Figures 1-5 It can be seen that the gold-plated palladium-copper wires in Examples 1 and 2 produced good sintered balls, while the gold-plated palladium-copper wires in Comparative Examples 5-1 to 5-3 produced eccentric sintered balls.

[0076] Test Example 4 Observe the surface of the gold-plated palladium-copper wires obtained in Example 1 and Comparative Example 4 (Comparative Example 4-1 and Comparative Example 4-2), such as Figure 6 and Figure 7 As shown.

[0077] Depend on Figure 6 and Figure 7It can be seen that the surface of the gold-plated palladium-copper wire in Comparative Example 4-2 has scratches.

[0078] Test Example 5 The gold-plated palladium-copper wires obtained in Examples 1-2, Comparative Examples 1, 2-3, 3-1, 4-1, and 4-2 were used for ball-burning. The ball-burning current was 50 mA and the ball-burning time was 340 μs. Then, FeCl3 etching solution was used for 10 s to remove the copper inside the FAB (free air sphere). The palladium coverage morphology was then observed. The results of Example 1 are as follows: Figure 8 As shown; the results of Example 2 are as follows Figure 9 As shown; the results of Comparative Example 1 are as follows. Figure 10 As shown; the results of Comparative Examples 2-3 are as follows. Figure 11 As shown; the results of Comparative Example 3-1 are as follows. Figure 12 As shown; the results of Comparative Example 4-1 are as follows. Figure 13 As shown; the results of Comparative Example 4-2 are as follows. Figure 14 As shown; Depend on Figures 8-14 It can be seen that the gold-plated palladium-copper wires provided in Examples 1 and 2 of the present invention have excellent corrosion resistance. However, the corrosion resistance of the gold-plated palladium-copper wires is significantly reduced in Comparative Example 1 due to direct palladium plating, in Comparative Examples 2-3 due to changes in the concentration ratio of complexing agent components in the chemical palladium plating solution, in Comparative Example 3-1 due to changes in the additive composition in the electroplating palladium solution, and in Comparative Examples 4-1 and 4-2 due to changes in the wire drawing speed.

[0079] Test Example 6 Three different batches of gold-plated palladium-copper wire obtained in Example 1 were used for ball sintering. The sintering current was 50 mA and the sintering time was 340 μs. Then, FeCl3 etching solution was used for 10 s to remove the copper inside the FAB (free air sphere). The palladium coverage morphology was then observed, and the results are as follows: Figures 15-17 As shown.

[0080] Depend on Figures 15-17 It can be seen that the gold-plated palladium copper wire provided in Embodiment 1 of the present invention has excellent batch-to-batch stability.

[0081] Test Example 7 The gold-plated palladium-copper wire obtained in Example 1 was used for ball sintering. The sintering current was 60 mA and the sintering time was 275 μs. Then, FeCl3 etching solution was used for 10 s to remove the copper inside the FAB (free air sphere). The palladium coating morphology was then observed, and the results are as follows: Figure 18 As shown; the burning current was 70mA, the burning time was 220us, and then FeCl3 etching solution was used for 10s to remove the copper inside the FAB (free air sphere). The palladium coverage morphology was then observed, and the results are as follows. Figure 19 As shown.

[0082] Depend on Figure 19 It can be seen that the gold-plated palladium copper wire provided in Embodiment 1 of the present invention can adapt to different ball-burning parameters while ensuring palladium coverage.

[0083] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for producing a corrosion-resistant gold-plated palladium copper wire, characterized by, The method comprises the following steps: Palladium is pre-plated on the surface of the copper base line by using a pre-plating palladium solution to form a first palladium layer; Palladium is further plated on the surface of the first palladium layer by using a further plating palladium solution to form a second palladium layer; gold is plated on the surface of the second palladium layer by using a gold plating solution to form a gold plating layer, thereby obtaining a semi-finished product; the semi-finished product is subjected to first annealing, wire drawing and second annealing, thereby obtaining the gold-plated palladium copper wire. The pre-plating palladium solution is a chemical plating palladium solution, and the chemical plating palladium solution comprises the following raw materials: 0.001-0.1 mol / L of soluble palladium salt, 0.05-1 mol / L of reducing agent, 0.05-5 mol / L of complexing agent, and the balance of water, and a buffer agent is used to adjust the pH to 6-8. The complexing agent comprises ethylenediamine, disodium ethylenediaminetetraacetate and acrylic acid at a concentration ratio of 0.1-0.3:0.005-0.015:0.2-0.

4.

2. The method of claim 1, wherein the gold-plated palladium-copper wire has corrosion resistance. The reducing agent comprises reducing agent A and reducing agent B at a concentration ratio of 10-50:1; the reducing agent A is at least one selected from hypophosphorous acid, sodium hypophosphite and phosphorous acid; and the reducing agent B is at least one selected from hydrazine, formic acid, formaldehyde, sodium formate and potassium formate.

3. The method of claim 1, wherein the gold-plated palladium-copper wire has corrosion resistance. The chemical plating palladium solution is replaced by an electroplating palladium solution, and the electroplating palladium solution comprises the following raw materials: 10-25 g / L of dichlorodiaminopalladium, 20-30 g / L of ammonium chloride, 35-60 g / L of ammonia water, 0.5-5 g / L of additive, and the balance of water, and a pH adjusting agent is used to adjust the pH to 6.5-8.

5.

4. The method for preparing the corrosion-resistant gold-plated palladium-copper wire according to claim 3, characterized in that, The additive comprises 2,5-dimercapto-1,3,4-thiadiazole, polydithiodipropyl sulfone sodium and perfluorooctene oxybenzenesulfonic acid sodium at a mass ratio of 1.5-2.5:1.5-2.5:0.002-0.

004.

5. The method for preparing the corrosion-resistant gold-plated palladium-copper wire according to claim 4, characterized in that, The further plating palladium solution is an electroplating palladium solution.

6. The method of claim 1, wherein the gold-plated palladium-copper wire has corrosion resistance. The gold plating solution comprises the following raw materials: 6-12 g / L of potassium citrate gold, 40-60 g / L of potassium carbonate, 0.4-1 g / L of dodecylpyridine hydrochloride, 0.3-0.8 g / L of pyridine sulfonic acid, 0.2-0.5 g / L of triethanolamine, the balance of deionized water, and a pH adjusting agent is used to adjust the pH to 5.5-6.

5.

7. The method of claim 1, wherein the gold-plated palladium-copper wire has corrosion resistance. The thickness of the first palladium layer is 10-20 nm; the thickness of the second palladium layer is 100-110 nm; and the thickness of the gold plating layer is 1-3 nm.

8. The method of claim 1, wherein the gold-plated palladium-copper wire has corrosion resistance. The wire drawing speed is 80-100 m / min.

9. The gold-plated palladium copper wire prepared by the method of any one of claims 1-8.

10. The gold-plated palladium copper wire of claim 9 for use in integrated circuit packaging.

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