A customer inquired that during the production process of using sulfate tin plating brightener, the solderability of the workpiece tin coating is unstable, leading to the phenomenon of some workpiece coatings falling off easily after high-temperature treatment. So what measures can we take during production to improve the solderability of the tin coating?
Based on on-site experience and the characteristics of the product sulfate tin plating brightener Sn-807, Bigley Technology has analyzed the following 9 measures to prevent hydrolysis of the plating solution, improve the solderability and corrosion resistance of the tin coating:
1. Regularly analyze and adjust the concentration of the plating solution, usually analyzing the plating solution before production every day and adjusting the concentration of each main salt within the process range.
2. Large area cathode plates are often used before or after production, and small current electrolytic plating solution is used to remove metal impurities and ions from the plating solution.
3. Regular use of Bigley's tetravalent tin treatment agent can convert tetravalent tin in the plating solution into divalent tin, maintaining the clarity of the plating solution.
4. High purity (99.99%) tin anode plate should be used as the anode plate, and the anode plate should be covered with an anode bag. At the same time, the anode plate should be washed frequently to prevent anode passivation.
5. Tin(II) sulfate without oxidation and yellowing shall be used as the main salt of the plating solution to ensure that the prepared or supplemented plating solution is clear and not turbid.
6. Control the temperature and current density of the plating solution. The temperature of the general plating solution should be controlled between 20-30 ℃, and it should be noted that the temperature of the plating solution should not exceed 30 ℃, otherwise the plating solution is prone to turbidity. The cathode current density should not be too high, and should generally be controlled between 0.5 to 2.0A/dm2 to prevent oxidation of the plating solution.
7. The workpiece should be fed into the groove using impulse current, especially for complex shaped workpieces, to prevent faults caused by strong acid corrosion.
8. During production, hanging fixtures should be regularly inspected and replaced to prevent faults caused by insulation skin damage, and to ensure the cleanliness of the plating solution to avoid cross contamination.
9. When the plating solution is discontinued, it should be covered to prevent excessive contact with air and reduce the oxidation of divalent tin.
Therefore, in the production process of using sulfate tin plating brightener, we should take the above 9 measures to strengthen the maintenance of the plating solution and ensure good solderability and corrosion resistance of the workpiece tin coating. If you are interested in sulfate tin plating brighteners, please contact Bigley customer service for free samples and detailed technical information!
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