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CN-122013269-A - Electroplating method of low-pore nanoscale bright tin layer

CN122013269ACN 122013269 ACN122013269 ACN 122013269ACN-122013269-A

Abstract

The application discloses an electroplating method of a low-pore nanoscale bright tin layer, which comprises the steps of placing a clean metal substrate in an activating solution containing a surface modifier, applying high pulse current to perform short-time impact to form a transition layer to obtain a target substrate, placing the target substrate in a nano composite tinning solution, and electroplating under the cooperation of a continuous ultrasonic field and a target waveform pulse current to form the low-pore nanoscale bright tin layer, wherein the nano composite tinning solution comprises stannous methanesulfonate, methanesulfonic acid, nano silicon carbide, nano silicon dioxide, a grain refiner, a dispersing agent, cinnamaldehyde, a vinyl pyrrolidone copolymer, ascorbic acid and a wetting agent, and the balance of deionized water. The binding force of the coating is improved when no primer layer is provided, and the reinforcement, compactness, brightness and environmental protection of the coating are realized.

Inventors

  • WU LIZHI
  • ZHANG LEI
  • WANG LI

Assignees

  • 惠州祥奇科技有限公司

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. A method for electroplating a low-porosity nanoscale bright tin layer, comprising: Placing a clean metal substrate in an activating solution, applying high pulse current to perform short-time impact to form a transition layer, and obtaining a target substrate; The target substrate is placed in a nano composite tinning solution, electroplating is carried out under the cooperation of a continuous ultrasonic field and a target waveform pulse current, and a low-pore nanoscale bright tin layer is formed, wherein each liter of the nano composite tinning solution comprises the following components: 60-120 g/L of stannous methanesulfonate, 100-200 mL/L of methanesulfonic acid, 5-15 g/L of nano silicon carbide, 5-15 g/L of nano silicon dioxide, 0.5-3 g/L of grain refiner, 3-5 g/L of dispersing agent, 2-5 mL/L of cinnamaldehyde, 5-15 mL/L of vinyl pyrrolidone copolymer, 0.1-0.5 g/L of ascorbic acid, 0.05-0.3 g/L of wetting agent and the balance of deionized water.
  2. 2. The method for electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the grain refiner is any one of magnesium sulfate, zinc sulfate and cobalt chloride, the dispersant is polyethylene glycol, and the wetting agent is perfluoroalkyl sulfonate.
  3. 3. The method for electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the method for preparing the nanocomposite tin plating solution comprises the steps of: Uniformly mixing nano silicon carbide, nano silicon dioxide, a dispersing agent and part of deionized water to obtain a nano suspension; Adding methanesulfonic acid into the other part of deionized water, stirring uniformly, adding stannous methanesulfonate and a grain refiner, and stirring until the stannous methanesulfonate and the grain refiner are completely dissolved to obtain main body basic solution; And under the stirring condition, slowly adding the nano suspension into the main body base solution, uniformly mixing, adding cinnamaldehyde, a vinyl pyrrolidone copolymer, ascorbic acid and a wetting agent, uniformly stirring, then fixing the volume, adjusting the pH value to 3.0-4.5, and carrying out combined cycle filtration and ultrasonic curing treatment to obtain the nano composite tinning solution.
  4. 4. The method of electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the target waveform pulse current is a ramp pulse current, the ramp pulse current is increased linearly from a start value of 0.5A/dm2 to 1A/dm2 to a peak value of 2A/dm2 to 5A/dm2, and then decreased linearly to an end value of 0.8A/dm2 to 1.5A/dm2, and a single period is 2s to 5s long.
  5. 5. The method of electroplating a low porosity nanoscale bright tin layer according to claim 4, wherein the ultrasonic field and the ramp pulse current are co-modulated such that ultrasonic waves continuously operate at a first power when the current density of the ramp pulse current is in a peak-up phase, and ultrasonic waves are switched to an intermittent mode of operation when the current density of the ramp pulse current is in a down phase, the intermittent mode of operation having a duty cycle of on for a first preset period of time followed by off for a second preset period of time, and on for a second power, the second power being greater than the first power.
  6. 6. The method of electroplating a low porosity nanoscale bright tin layer according to claim 5, wherein the first power is 300w to 500w, the second power is 600w to 900w, and the ultrasonic frequency mode is a dual-frequency composite mode comprising a low frequency of 28khz to 40khz and a high frequency of 80khz to 100 khz.
  7. 7. The method for electroplating a low porosity nanoscale bright tin layer according to claim 1, wherein each liter of the activation solution comprises the following components: 5g/L to 20g/L of n-stannous salt, 0.5 g to 3g/L of polyethylene glycol octyl phenyl ether or fatty alcohol polyoxyethylene, 10g/L to 30g/L of complexing agent and the balance of deionized water, wherein the complexing agent is one or more of tartaric acid, citric acid or gluconic acid.
  8. 8. The method for electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the method for preparing the activation solution comprises the steps of: Dissolving a complexing agent in part of deionized water, adding n-divalent tin salt, stirring until the n-divalent tin salt is completely dissolved to obtain a tin complex solution, adding polyethylene glycol octyl phenyl ether or fatty alcohol polyoxyethylene into the tin complex solution, stirring uniformly, adding the rest deionized water to fix the volume, and regulating the pH value to 1.0-3.0 to obtain the activating solution.
  9. 9. The method of electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the high pulse current has a forward peak current density of 10A/dm2 to 30A/dm2, a pulse width of 0.1ms to 1ms, a frequency of 50hz to 200hz, and an impact time of 10s to 60s.
  10. 10. The method for electroplating a low-porosity nanoscale bright tin layer according to claim 1, wherein the clean metal substrate is any one or more of a clean-treated aluminum alloy, copper alloy, magnesium alloy, stainless steel, and carbon steel.

Description

Electroplating method of low-pore nanoscale bright tin layer Technical Field The application relates to the technical field of electroplating, in particular to an electroplating method of a low-pore nanoscale bright coating. Background Tin plating is widely used in the fields of electronic components and the like due to its excellent solderability, conductivity and corrosion resistance. With the development of miniaturization and high reliability of electronic products, requirements of low porosity, high brightness and strong binding force are put forward on tin plating layers. For this reason, conventional processes typically rely on a multi-layered priming system such as "zincate-copper cyanide-copper acid" with the addition of brighteners and nanoparticles (e.g.)、)。 However, the traditional priming process flow is long and involves extremely toxic cyanide, the environmental protection pressure is high, the conventional brightening agent tends to increase the internal stress of the coating and reduce the toughness while pursuing high brightness, and is easier to peel off due to stress during direct plating, and the directly added nano particles are extremely easy to agglomerate and settle in the strong acid plating solution, so that the nano scale effect cannot be exerted, the instability of the plating solution is aggravated, defects are formed in the coating, and the porosity is increased and the performance is uneven. Dispersing agents, while partially mitigating agglomeration, have difficulty in maintaining long-term uniform dispersion of nanoparticles and effective co-deposition with metal ions during the dynamic process of electrodeposition. Therefore, how to synchronously realize the ultra-high binding force, low porosity, bright mirror surface and green and stable process of the plating layer on the substrate on the premise of omitting the priming layer is still a technical bottleneck to be broken through in the current urgent need. Disclosure of Invention The application provides an electroplating method of a low-pore nanoscale bright coating, which aims to solve the technical problems that the ultra-high binding force, low porosity, bright mirror surface and green and stable process of the coating cannot be realized by the traditional process. The application provides an electroplating method of a low-pore nanoscale bright tin layer, which comprises the following steps: Placing a clean metal substrate in an activating solution, applying high pulse current to perform short-time impact to form a transition layer, and obtaining a target substrate; The target substrate is placed in a nano composite tinning solution, electroplating is carried out under the cooperation of a continuous ultrasonic field and a target waveform pulse current, and a low-pore nanoscale bright tin layer is formed, wherein each liter of the nano composite tinning solution comprises the following components: 60-120 g/L of stannous methanesulfonate, 100-200 mL/L of methanesulfonic acid, 5-15 g/L of nano silicon carbide, 5-15 g/L of nano silicon dioxide, 0.5-3 g/L of grain refiner, 3-5 g/L of dispersing agent, 2-5 mL/L of cinnamaldehyde, 5-15 mL/L of vinyl pyrrolidone copolymer, 0.1-0.5 g/L of ascorbic acid, 0.05-0.3 g/L of wetting agent and the balance of deionized water. Optionally, the particle size of the nano silicon carbide and the nano silicon dioxide is 10 nm-50 nm. In some embodiments, the grain refiner is any one of magnesium sulfate, zinc sulfate and cobalt chloride, the dispersant is polyethylene glycol, and the wetting agent is perfluoroalkyl sulfonate. In some embodiments, the method of preparing the nanocomposite tin plating solution includes the steps of: Uniformly mixing nano silicon carbide, nano silicon dioxide, a dispersing agent and part of deionized water to obtain a nano suspension; Adding methanesulfonic acid into the other part of deionized water, stirring uniformly, adding stannous methanesulfonate and a grain refiner, and stirring until the stannous methanesulfonate and the grain refiner are completely dissolved to obtain main body basic solution; And under the stirring condition, slowly adding the nano suspension into the main body base solution, uniformly mixing, adding cinnamaldehyde, a vinyl pyrrolidone copolymer, ascorbic acid and a wetting agent, uniformly stirring, then fixing the volume, adjusting the pH value to 3.0-4.5, and carrying out combined cycle filtration and ultrasonic curing treatment to obtain the nano composite tinning solution. In some embodiments, the target waveform pulse current is a ramp pulse current, the ramp pulse current is linearly increased from a start value of 0.5A/dm2 to 1A/dm2 to a peak value of 2A/dm2 to 5A/dm2, and then linearly decreased to an end value of 0.8A/dm2 to 1.5A/dm2, and the single period is 2s to 5s long. In some embodiments, the ultrasonic field and the ramp pulse current are modulated cooperatively, wherein the ultrasonic wave continuously operates at