Metal impurities in the tin plating solution such as copper ions and iron ions can interfere with the tin plating process. These impurity metals can be co-deposited during the plating process, resulting in an impure composition of the plated layer, which in turn affects the physical and chemical properties of the plated layer. Therefore, it is necessary to know how to remove impurities from tin plating solution.
Removal of impurities
After plating for a period of time, the anode is easy to passivation, the plating solution is cloudy, the sludge is increased, the current efficiency is decreased, the surface of the coating appears fog and spots, the brightness decreases, the crystallization is rough and loose, and the welding performance is not good. The treatment method is: add polypropionamide, static precipitation, discard the cylinder foot.
Be careful not to bring Cl- and NO3- into the plating solution. When Cl- exceeds 0.3g/L and NO3- exceeds 0.6g/L, the plating layer will appear dark and have pinholes, and at the same time, it will reduce the ability of the plating solution to plating deeply, and in this way, the plating solution will be very difficult to handle. When Fe2+ and Cu2+ in the plating solution exceeds 0.5g/L, the plating layer becomes dark and the porosity increases. If we want to remove the cations, we can consider using a small cathodic current density for treatment (which takes several hours), and Cu2+ can also be removed with potassium ferrocyanide solution.
The organic decomposition can then be removed by activated carbon adsorption. In order to slow down the production of organic decomposition products, we can use Bigely acid bright tin plating additive, which has a slow decomposition rate of organic matter.
When the plating solution in the electroplating plant is discontinued, it is often necessary to use a corrugated plate (some people call it a false cathode) for low current electrolysis.
Conclusion
When we use acid bright tin plating additives, the impurities in the plating solution mentioned above must be removed in time, otherwise it will cause two problems, firstly, it is difficult to plating qualified products, and secondly, the impurities accumulated over time will increase the difficulty of plating solution treatment. Based on this, Bigely engineers will provide customers with corresponding solutions.
If you want to know more about the solution for impurities in acid tin plating brightener, please contact us.
