During the use of acidic tin brightener, what parameters should be monitored to maintain stable production of the plating solution?
Based on on-site experience and product characteristics, Bigely Technology has conducted the following analysis:
1.Stannous sulfate. The allowable content range of stannous sulfate is very wide, even if the content is only a dozen grams per liter, it can still produce a coating with normal color and brightness. Therefore, its high or low content mainly affects the current density, especially for hanging plating.
2. Sulfuric acid. Although the allowable range of sulfuric acid content is wide, it must be carefully controlled. Excessive or insufficient sulfuric acid content is detrimental to anodic dissolution, especially when it is too low. It not only passivates the anode, but also hydrolyzes Sn2+ions into Sn4+ions, deteriorating the performance of the solution and reducing the brightness of the tin coating. Under the condition of no passivation and washing on the tin plate, if the voltage increases, it means that the sulfuric acid content is too low, and sulfuric acid must be added. It can be added in small amounts several times until the voltage returns to normal.
3. The temperature of the plating solution. Lower temperature control of the plating solution is beneficial for the stability of the solution performance and for denser crystallization of the tin coating. Low solution temperature, low consumption of brightener, and good coating brightness; When the solution temperature is high, the situation is the opposite.
4. Current density. It can be calculated based on the actual area of the plated part, and the cathode current density should be controlled at 0.5-3.5 A/dm2. Alternatively, under the condition that there are no large bubbles on the liquid surface, try to increase the current as much as possible.
By paying attention to the above parameters during the use of acidic tin plating brightener, stable production of the plating solution can be maintained.
