Insufficient pre-removal of electroplating; Most plates are coated with an antioxidant during processing. If the oxide film is not completely removed, it will lead to poor coating. Because copper is plated first in the process, it can be verified whether copper and copper are separated. The solution is to remove the oxide film on the surface by brush coating or anodic electrolysis, and then electroplate.
If the nickel coating falls off from the copper coating, it may be because there are too many brighteners and the tensile stress of the nickel coating is too high. Adjust the proportion of brightener in nickel plating solution, and remove excess brightener by electrolysis.
In addition, too high pH value will also lead to peeling of nickel plating. If the pH value is controlled between 3.5 and 4.5 (depending on the nature of brightener), it is also necessary to consider whether the brightener system is suitable. It is recommended to use semi-gloss system brightener.
Excessive organic impurities or metal impurities in nickel plating solution can also lead to excessive stress in nickel plating layer, which can be removed by weak electrolysis or activated carbon.
If it is between Sn and Ni, it may be:
After nickel plating, it stays in air or water for too long, so it is recommended not to exceed 1 minute.
The polishing agent for nickel plating is unbalanced and the stress of the coating is too large. It is recommended to use a single dose of semi-gloss agent.