Preparation method of palladium-plated copper wire

Abstract

The invention relates to the technical field of copper wire palladium plating, in particular to a preparation method of a palladium-plated copper wire, which comprises the following steps: S1, cleaning a bonding copper wire; s2, plating palladium on a bonding copper wire; s3, vacuum annealing; the preparation method of the palladium plating liquid comprises the following steps: S21, preparation of a component A: adding polyethylene glycol, silica sol with the concentration of 20%, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and uniformly stirring at normal temperature to obtain the component A; s22, preparation of a component B: adding a silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano palladium powder into a flask, and uniformly stirring at normal temperature to obtain the component B; and S23, mixing. According to the palladium-plated copper wire prepared by the preparation method of the palladium-plated copper wire in the technical scheme, the quality of the palladium layer is improved by improving the distribution uniformity of the palladium layer and improving the high-temperature resistance of the palladium layer, and the bonding capacity of the palladium layer and the copper wire is improved by reducing the size of palladium powder particles, so that the effect of preventing the palladium layer from falling off is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of palladium plating of copper wires, and in particular to a method for preparing palladium-plated copper wires. Background Art

[0002] Gold wire bonding packaging is a very important technology in the field of semiconductor packaging. It involves using gold wire (or other metal wires) to connect the pads on the chip to the lead frame to achieve the transmission of electrical signals. In order to achieve narrow pitch and long distance bonding with thinner wire diameter and better performance, palladium-plated copper bonding wire is gradually attracting the attention of the packaging industry due to its good bonding performance and has become the best alternative material to gold bonding wire.

[0003] Palladium-plated copper bonding wire is a special wire with a metal copper wire as the base material and a metal palladium plated outer layer. It mainly adopts electroplating and chemical plating technology. However, the waste liquid generated during the electroplating process is prone to heavy metal pollution. There are also problems such as complex process and high equipment cost. Direct palladium plating technology is to immerse the copper wire in an organic solution containing nano-palladium powder and various additives, and then deposit a nano-palladium film on the surface of the copper wire through a heat treatment process, which solves the problems of environmental pollution and coating shedding during the traditional electroplating subsequent drawing process.

[0004] However, the palladium-plated copper wire currently prepared by direct palladium plating technology has the following factors that lead to damage of the plating layer and exposure of the copper wire:

[0005] 1. In the traditional palladium plating process, palladium particles often agglomerate, resulting in uneven plating;

[0006] 2. After the traditional palladium plating, it is annealed at high temperature. Due to the insufficient heat resistance of the plating, the plating will fall off and oxidize;

[0007] 3. The palladium particles obtained by the traditional palladium plating process are large and have a high melting point. The interface bonding strength and flatness between the plating layer and the copper wire are poor.

[0008] Damaged coating and exposed copper wire will cause the palladium-plated copper wire to corrode in a humid or high-salt environment, leading to surface oxidation and reduced material performance.

[0009] In view of the above problems, a method for preparing palladium-plated copper wire is designed. Summary of the invention

[0010] In order to solve at least one of the above technical problems, a palladium-plated copper wire with a palladium layer that is not easily damaged is developed. The present application provides a method for preparing the palladium-plated copper wire.

[0011] On the one hand, the present application provides a method for preparing a palladium-plated copper wire, comprising the following steps:

[0012] S1. Cleaning of bonding copper wire: Immerse the bonding copper wire in ethanol for ultrasonic cleaning, and then blow dry for later use;

[0013] S2. Palladium plating of bonding copper wire: at room temperature, immerse the cleaned copper wire in a beaker filled with palladium plating solution, and obtain the palladium-plated copper wire by magnetic stirring;

[0014] S3, vacuum annealing: the palladium-plated copper wire is subjected to ultrasonic washing with distilled water, and then subjected to vacuum annealing to obtain the palladium-plated copper wire;

[0015] Wherein, the preparation method of the palladium plating solution comprises the following steps:

[0016] S21, preparation of component A: adding polyethylene glycol, 20% concentration of silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stirring at room temperature to obtain component A;

[0017] S22, preparation of component B: adding silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stirring at room temperature to obtain component B;

[0018] S23, mixing: mixing components A and B at a mass ratio of 1 to 1.5:1 and stirring for 1 hour to obtain the palladium plating solution.

[0019] Optionally, the components in the A component are calculated by weight percentage as follows:

[0020] Polyethylene glycol 1% to 6%, 20% concentration of silica sol 0.5% to 4%, polyoxyethylene nonylphenol ether 1% to 5%, propanol 62.5% to 75%, ethanol 10% to 30%.

[0021] Optionally, the components in the B component are calculated by weight percentage as follows:

[0022] Silane coupling agent 0.01%-0.1%, methyltrioxysilane 0.5%-4%, polyoxyethylene nonylphenol ether 1%-5%, isopropanol 64%-72%, ethanol 10%-30%, nano palladium powder 2%-10%.

[0023] Optionally, the mass ratio of components A and B in the palladium plating solution in step S23 is 1.2:1.

[0024] Optionally, in step S1, the bonding copper wire is immersed in ethanol and ultrasonically cleaned at an intensity of 20 to 60 Hz.

[0025] Optionally, in step S1, the bonding copper wire is immersed in ethanol for ultrasonic cleaning for 10 minutes.

[0026] Optionally, in step S2, the magnetic stirring time is 5 to 30 minutes.

[0027] Optionally, in step S3, the temperature of the vacuum annealing treatment is 450° C. to 550° C., and the time of the vacuum annealing treatment is 2 to 3 seconds.

[0028] In a second aspect, the present application provides a palladium-plated copper wire, which is prepared according to the above-mentioned method for preparing a palladium-plated copper wire.

[0029] In summary, the beneficial effects of the present invention are:

[0030] A preparation method of a palladium-plated copper wire in the technical solution, 1. In view of the agglomeration of palladium particles that often occurs in the traditional palladium plating process, a new palladium plating solution is used, and the copper wire is immersed in the palladium plating solution and magnetically stirred, so that the surface of the palladium layer is uniform and smoother, and it is not easy to delaminate or break the layer, thereby maintaining the surface uniformity of the gold-plated copper wire.

[0031] 2. After the traditional palladium plating, the high temperature annealing treatment is performed. Due to the insufficient heat resistance of the coating, the palladium layer will fall off and oxidize. 20% concentration of silica sol is added to the palladium plating solution. Since the bond energy of the silicon-oxygen bond (Si-O-Si) is high, the crystal structure is relatively stable and it is not easy to undergo phase change or lattice distortion even in a high temperature environment. Therefore, the palladium plating solution can withstand high temperatures and show a good coating at high temperatures.

[0032] 3. In order to solve the problem that the palladium particles obtained by the traditional palladium plating process are large, have a high melting point, and the interface bonding strength and flatness between the plating layer and the copper wire are poor, nano-palladium powder is selected for high-temperature annealing treatment and high-temperature sintering of the nano-palladium powder to obtain smaller palladium particles, which are combined with the interface of the copper wire during the sintering process to improve the flatness.

[0033] The palladium-plated copper wire prepared by the preparation method of the palladium-plated copper wire in the technical scheme improves the uniformity of the distribution of the palladium layer and the high temperature resistance of the palladium layer, thereby improving the quality of the palladium layer, and reduces the size of the palladium powder particles, thereby improving the bonding ability between the palladium layer and the copper wire, thereby preventing the palladium layer from falling off, and solving the problem that the palladium-plated copper wire will corrode in a humid or high-salt environment due to the leakage of the copper wire caused by the falling off of the palladium layer, resulting in surface oxidation and reduced material performance. DETAILED DESCRIPTION

[0034] The present application is further described in detail below with reference to the embodiments.

[0035] A method for preparing a palladium-plated copper wire comprises the following steps:

[0036] S1. Cleaning of bonding copper wire: Immerse the bonding copper wire in ethanol for ultrasonic cleaning, and then blow dry for later use;

[0037] S2. Palladium plating of bonding copper wire: at room temperature, immerse the cleaned copper wire in a beaker filled with palladium plating solution, and obtain the palladium-plated copper wire by magnetic stirring;

[0038] S3, vacuum annealing: the palladium-plated copper wire is subjected to ultrasonic washing with distilled water, and then subjected to vacuum annealing to obtain the palladium-plated copper wire;

[0039] Wherein, the preparation method of the palladium plating solution comprises the following steps:

[0040] S21, preparation of component A: adding polyethylene glycol, 20% concentration of silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stirring at room temperature to obtain component A;

[0041] S22, preparation of component B: adding silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropyl alcohol, ethanol and nano-palladium powder into a flask, and stirring evenly at room temperature to obtain component B; the silane coupling agent in this technical solution adopts silane coupling agent A151;

[0042] S23, mixing: mixing components A and B at a mass ratio of 1 to 1.5:1 and stirring for 1 hour to obtain the palladium plating solution.

[0043] A palladium-plated copper wire is prepared according to the above-mentioned method for preparing a palladium-plated copper wire.

[0044] A preparation method of a palladium-plated copper wire in the technical solution, 1. In view of the agglomeration of palladium particles that often occurs in the traditional palladium plating process, a new palladium plating solution is used, and the copper wire is immersed in the palladium plating solution and magnetically stirred, so that the surface of the palladium layer is uniform and smoother, and it is not easy to delaminate or break the layer, thereby maintaining the surface uniformity of the gold-plated copper wire.

[0045] 2. After the traditional palladium plating, the high temperature annealing treatment is performed. Due to the insufficient heat resistance of the coating, the palladium layer will fall off and oxidize. 20% concentration of silica sol is added to the palladium plating solution. Since the bond energy of the silicon-oxygen bond (Si-O-Si) is high, the crystal structure is relatively stable and it is not easy to undergo phase change or lattice distortion even in a high temperature environment. Therefore, the palladium plating solution can withstand high temperatures and show a good coating at high temperatures.

[0046] 3. In order to solve the problem that the palladium particles obtained by the traditional palladium plating process are large, have a high melting point, and the interface bonding strength and flatness between the plating layer and the copper wire are poor, nano-palladium powder is selected for high-temperature annealing treatment and high-temperature sintering of the nano-palladium powder to obtain smaller palladium particles, which are combined with the interface of the copper wire during the sintering process to improve the flatness.

[0047] The palladium-plated copper wire prepared by the preparation method of the palladium-plated copper wire in the technical scheme improves the uniformity of the distribution of the palladium layer and the high temperature resistance of the palladium layer, thereby improving the quality of the palladium layer, and reduces the size of the palladium powder particles, thereby improving the bonding ability between the palladium layer and the copper wire, thereby preventing the palladium layer from falling off, and solving the problem that the palladium-plated copper wire will corrode in a humid or high-salt environment due to the leakage of the copper wire caused by the falling off of the palladium layer, resulting in surface oxidation and reduced material performance. Specific embodiments

[0049] Preparation Examples 1 to 5 are used to prepare component A in this technical solution, and are specifically as follows.

[0050] Preparation Example 1

[0051] Component A in this preparation example includes, by mass percentage, 1% polyethylene glycol, 0.8% 20% silica sol, 3% polyoxyethylene nonylphenol ether, 70% propanol, and 25.2% ethanol.

[0052] Add the above-mentioned amount of polyethylene glycol, 20% concentration silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stir evenly at room temperature to obtain component A.

[0053] Preparation Example 2

[0054] Component A in this preparation example includes, by mass percentage, 1% polyethylene glycol, 0.8% 20% silica sol, 1% polyoxyethylene nonylphenol ether, 70% propanol, and 27.2% ethanol.

[0055] Add the above-mentioned amount of polyethylene glycol, 20% concentration silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stir evenly at room temperature to obtain component A.

[0056] Preparation Example 3

[0057] Component A in this preparation example includes, by mass percentage, 3% polyethylene glycol, 0.5% 20% silica sol, 4% polyoxyethylene nonylphenol ether, 62.5% propanol, and 30% ethanol.

[0058] Add the above-mentioned amount of polyethylene glycol, 20% concentration silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stir evenly at room temperature to obtain component A.

[0059] Preparation Example 4

[0060] Component A in this preparation example includes, by mass percentage, 5% polyethylene glycol, 2.5% 20% silica sol, 2% polyoxyethylene nonylphenol ether, 72% propanol, and 18.5% ethanol.

[0061] Add the above-mentioned amount of polyethylene glycol, 20% concentration silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stir evenly at room temperature to obtain component A.

[0062] Preparation Example 5

[0063] Component A in this preparation example includes, by mass percentage, 6% polyethylene glycol, 4% 20% silica sol, 5% polyoxyethylene nonylphenol ether, 75% propanol, and 10% ethanol.

[0064] Add the above-mentioned amount of polyethylene glycol, 20% concentration silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stir evenly at room temperature to obtain component A.

[0065] Preparation Examples 6 to 10 are used to prepare component B in this technical solution, and the details are as follows.

[0066] Preparation Example 6

[0067] Component B includes, by mass percentage, 0.06% of silane coupling agent, 1% of methyltrioxysilane, 3% of polyoxyethylene nonylphenol ether, 70% of isopropanol, 20.94% of ethanol, and 5% of nano palladium powder.

[0068] Add silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stir evenly at room temperature to obtain component B.

[0069] Preparation Example 7

[0070] Component B includes, by mass percentage, 0.02% of silane coupling agent, 1% of methyltrioxysilane, 1% of polyoxyethylene nonylphenol ether, 70% of isopropanol, 22.98% of ethanol, and 5% of nano palladium powder.

[0071] Add silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stir evenly at room temperature to obtain component B.

[0072] Preparation Example 8

[0073] Component B includes, by mass percentage, 0.08% of silane coupling agent, 4% of methyltrioxysilane, 4% of polyoxyethylene nonylphenol ether, 72% of isopropanol, 10% of ethanol, and 10% of nano palladium powder.

[0074] Add silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stir evenly at room temperature to obtain component B.

[0075] Preparation Example 9

[0076] Component B includes, by mass percentage, 0.1% of silane coupling agent, 2% of methyltrioxysilane, 2% of polyoxyethylene nonylphenol ether, 64% of isopropanol, 30% of ethanol, and 2% of nano palladium powder.

[0077] Add silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stir evenly at room temperature to obtain component B.

[0078] Preparation Example 10

[0079] Component B includes, by mass percentage, 0.04% of silane coupling agent, 0.5% of methyltrioxysilane, 5% of polyoxyethylene nonylphenol ether, 68% of isopropanol, 18.3% of ethanol, and 8% of nano palladium powder.

[0080] Add silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stir evenly at room temperature to obtain component B.

[0081] Example 1

[0082] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0083] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0084] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 20 minutes.

[0085] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0086] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 1 and the component B prepared in Preparation Example 6 are mixed and stirred at a mass ratio of 1:1 for 1 hour to obtain the palladium plating solution.

[0087] Example 2

[0088] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0089] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0090] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 10 minutes.

[0091] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0092] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 2 and the component B prepared in Preparation Example 7 are mixed and stirred at a mass ratio of 1:1 for 1 hour to obtain the palladium plating solution.

[0093] Example 3

[0094] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0095] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0096] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 5 minutes.

[0097] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0098] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 3 and the component B prepared in Preparation Example 8 are mixed and stirred at a mass ratio of 1:1 for 1 hour to obtain the palladium plating solution.

[0099] Example 4

[0100] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0101] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0102] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 15 minutes.

[0103] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0104] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 4 and the component B prepared in Preparation Example 9 are mixed and stirred at a mass ratio of 1:1 for 1 hour to obtain the palladium plating solution.

[0105] Example 5

[0106] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0107] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0108] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 30 minutes.

[0109] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 500° C. and the vacuum annealing time is 3 seconds.

[0110] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 5 and the component B prepared in Preparation Example 10 are mixed and stirred at a mass ratio of 1:1 for 1 hour to obtain the palladium plating solution.

[0111] Comparative Example 1

[0112] This comparative example is used to prepare a palladium-plated copper wire. Based on Example 1, only component A in the palladium plating solution is changed. Component A in this comparative example includes, by mass percentage, 1% polyethylene glycol, 70% propanol, and 29% ethanol.

[0113] Add the above-mentioned amounts of polyethylene glycol, propanol and ethanol into a flask and stir evenly at room temperature to obtain component A.

[0114] Comparative Example 2

[0115] This comparative example is used to prepare a palladium-plated copper wire. On the basis of Example 1, only component B in the palladium plating solution is changed. Component B in this comparative example includes, by mass percentage, 0.06% silane coupling agent, 70% isopropanol, 24.94% ethanol, and 5% nano palladium powder.

[0116] Add silane coupling agent, isopropanol, ethanol and nano-palladium powder into a flask and stir evenly at room temperature to obtain component B.

[0117] Comparative Example 3

[0118] This comparative example is used to prepare a palladium-plated copper wire, using the palladium-plated copper wire prepared in Example 202210593726.5.

[0119] The palladium-plated copper wires prepared in the above Examples 1 to 5 and Comparative Examples 1 to 3 were tested, and the test results are shown in Table 1.

[0120] Table 1

[0121]

[0122]

[0123] It can be seen from Examples 1 to 5, Comparative Examples 1 to 3 and Table 1 that the palladium-plated copper wire prepared by the technical solution of the present application has a smooth and flat surface, no palladium powder agglomeration, a tensile strength of more than 245 MPa, a resistivity of less than 1.9 μΩ.cm, and no corrosion or shedding in the salt spray resistance test.

[0124] Compared with comparative examples 1 to 2, the palladium-plated copper wire prepared by the technical solution of the present application reduces the agglomeration of palladium powder, and the surface of the palladium-plated copper wire is smoother and flatter; and the tensile strength is significantly improved, the resistivity is significantly reduced, and the salt spray resistance is greatly enhanced.

[0125] Compared with Comparative Example 3, the palladium-plated copper wire prepared by the technical solution of the present application has significantly improved tensile strength, further reduced resistivity, and significantly enhanced salt spray resistance.

[0126] In order to verify the effect of the weight ratio of component A to component B on the palladium plating solution, the inventors prepared the following Examples 6 to 15, which are as follows.

[0127] Examples 6 to 10 are based on Examples 1 to 5, except that the weight ratio of component A to component B is changed to 1.2:1, as follows.

[0128] Example 6

[0129] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0130] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0131] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 20 minutes.

[0132] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0133] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 1 and the component B prepared in Preparation Example 6 are mixed and stirred at a mass ratio of 1.2:1 for 1 hour to obtain the palladium plating solution.

[0134] Example 7

[0135] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0136] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0137] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 10 minutes.

[0138] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0139] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 2 and the component B prepared in Preparation Example 7 are mixed and stirred at a mass ratio of 1.2:1 for 1 hour to obtain the palladium plating solution.

[0140] Example 8

[0141] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0142] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0143] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 5 minutes.

[0144] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0145] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 3 and the component B prepared in Preparation Example 8 are mixed and stirred at a mass ratio of 1.2:1 for 1 hour to obtain the palladium plating solution.

[0146] Example 9

[0147] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0148] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0149] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 15 minutes.

[0150] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0151] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 4 and the component B prepared in Preparation Example 9 are mixed and stirred at a mass ratio of 1.2:1 for 1 hour to obtain the palladium plating solution.

[0152] Example 10

[0153] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0154] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0155] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 30 minutes.

[0156] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 500° C. and the vacuum annealing time is 3 seconds.

[0157] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 5 and the component B prepared in Preparation Example 10 are mixed and stirred at a mass ratio of 1.2:1 for 1 hour to obtain the palladium plating solution.

[0158] The palladium-plated copper wires prepared in the above Examples 6 to 10 were tested, and the test results are shown in Table 2.

[0159] Table 2

[0160] Palladium-plated copper wire A:B Surface condition Tensile strength MPa Resistivity μΩ.cm Salt spray resistance Example 6 1.2:1 Smooth and flat 275 1.47 No corrosion, no shedding Example 7 1.2:1 Smooth and flat 271 1.57 No corrosion, no shedding Example 8 1.2:1 Smooth and flat 272 1.79 No corrosion, no shedding Example 9 1.2:1 Smooth and flat 269 1.55 No corrosion, no shedding Example 10 1.2:1 Smooth and flat 266 1.65 No corrosion, no shedding

[0161] Examples 11 to 15 are based on Examples 1 to 5, but the weight ratio of component A to component B is changed to 1.5:1, as follows.

[0162] Embodiment 11

[0163] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0164] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0165] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 20 minutes.

[0166] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0167] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 1 and the component B prepared in Preparation Example 6 are mixed and stirred at a mass ratio of 1.5:1 for 1 hour to obtain the palladium plating solution.

[0168] Example 12

[0169] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0170] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0171] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 10 minutes.

[0172] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 550° C. and the vacuum annealing time is 3 seconds.

[0173] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 2 and the component B prepared in Preparation Example 7 are mixed and stirred at a mass ratio of 1.5:1 for 1 hour to obtain the palladium plating solution.

[0174] Example 13

[0175] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0176] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0177] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 5 minutes.

[0178] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0179] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 3 and the component B prepared in Preparation Example 8 are mixed and stirred at a mass ratio of 1.5:1 for 1 hour to obtain the palladium plating solution.

[0180] Embodiment 14

[0181] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0182] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0183] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 15 minutes.

[0184] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 450° C. and the vacuum annealing time is 3 seconds.

[0185] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 4 and the component B prepared in Preparation Example 9 are mixed and stirred at a mass ratio of 1.5:1 for 1 hour to obtain the palladium plating solution.

[0186] Embodiment 15

[0187] This embodiment is used to prepare a palladium-plated copper wire, and the specific steps are as follows.

[0188] The bonding copper wire was immersed in ethanol for ultrasonic cleaning and then blown dry for later use; the intensity of ultrasonic cleaning was 60 Hz and the cleaning time was 10 min.

[0189] At room temperature, the cleaned copper wire is immersed in a beaker filled with palladium plating solution, and the palladium-plated copper wire is obtained by magnetic stirring; the magnetic stirring time is 30 minutes.

[0190] The palladium-plated copper wire is subjected to ultrasonic washing with distilled water and then subjected to vacuum annealing to obtain the palladium-plated copper wire; the vacuum annealing temperature is 500° C. and the vacuum annealing time is 3 seconds.

[0191] The preparation method of the palladium plating solution is as follows: the component A prepared in Preparation Example 5 and the component B prepared in Preparation Example 10 are mixed and stirred at a mass ratio of 1.5:1 for 1 hour to obtain the palladium plating solution.

[0192] The palladium-plated copper wires prepared in the above Examples 11 to 15 were tested, and the test results are shown in Table 3.

[0193] Table 3

[0194] Palladium-plated copper wire A:B Surface condition Tensile strength MPa Resistivity μΩ.cm Salt spray resistance Embodiment 11 1.5:1 Smooth and flat 268 1.50 No corrosion, no shedding Example 12 1.5:1 Smooth and flat 266 1.59 No corrosion, no shedding Example 13 1.5:1 Smooth and flat 260 1.83 No corrosion, no shedding Embodiment 14 1.5:1 Smooth and flat 266 1.58 No corrosion, no shedding Embodiment 15 1.5:1 Smooth and flat 264 1.67 No corrosion, no shedding

[0195] It can be seen from Examples 1 to 5, Examples 6 to 10, and Examples 11 to 15 and Tables 1 to 3 that in the technical scheme of the present application, adjusting the weight ratio of component A to component B in the palladium plating solution can affect the strength and electrical properties of the palladium plating layer on the surface of the palladium-plated copper wire. When the weight ratio of component A to component B in the palladium plating solution is 1.2:1, the tensile strength of the prepared palladium-plated copper wire is significantly improved and the resistivity is significantly reduced.

[0196] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a palladium-plated copper wire, characterized in that: The following steps are involved: S1. Cleaning of bonding copper wire: Immerse the bonding copper wire in ethanol for ultrasonic cleaning, and then blow dry for later use; S2. Palladium plating of bonding copper wire: at room temperature, immerse the cleaned copper wire in a beaker filled with palladium plating solution, and obtain the palladium-plated copper wire by magnetic stirring; S3, vacuum annealing: the palladium-plated copper wire is subjected to ultrasonic washing with distilled water, and then subjected to vacuum annealing to obtain the palladium-plated copper wire; Wherein, the preparation method of the palladium plating solution comprises the following steps: S21, preparation of component A: adding polyethylene glycol, 20% concentration of silica sol, polyoxyethylene nonylphenol ether, propanol and ethanol into a flask, and stirring at room temperature to obtain component A; S22, preparation of component B: adding silane coupling agent, methyltrioxysilane, polyoxyethylene nonylphenol ether, isopropanol, ethanol and nano-palladium powder into a flask, and stirring at room temperature to obtain component B; S23, mixing: mixing components A and B at a mass ratio of 1 to 1.5:1 and stirring for 1 hour to obtain the palladium plating solution.

2. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: The components in the A component are calculated by weight percentage: Polyethylene glycol 1% to 6%, 20% concentration of silica sol 0.5% to 4%, polyoxyethylene nonylphenol ether 1% to 5%, propanol 62.5% to 75%, ethanol 10% to 30%.

3. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: The components in the B component are calculated by weight percentage: Silane coupling agent 0.01%-0.1%, methyltrioxysilane 0.5%-4%, polyoxyethylene nonylphenol ether 1%-5%, isopropanol 64%-72%, ethanol 10%-30%, nano palladium powder 2%-10%.

4. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: The mass ratio of components A and B in the palladium plating solution in step S23 is 1.2:

1.

5. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: In the step S1, the bonding copper wire is immersed in ethanol and ultrasonically cleaned at an intensity of 20 to 60 Hz.

6. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: In the step S1, the bonding copper wire is immersed in ethanol for ultrasonic cleaning for 10 minutes.

7. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: In step S2, the magnetic stirring time is 5 to 30 minutes.

8. The method for preparing a palladium-plated copper wire according to claim 1, characterized in that: In the step S3, the temperature of the vacuum annealing treatment is 450° C. to 550° C., and the time of the vacuum annealing treatment is 2 to 3 seconds.

9. A palladium-plated copper wire, characterized in that: The method for preparing a palladium-plated copper wire according to any one of claims 1 to 8 is used.

Images