During the application of medium-phosphorus electroless nickel plating solution, sometimes pinholes appear in the electroless nickel coating of the workpiece. What is going on?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product's medium-phosphorus electroless nickel plating solution Ni-809,There are six main reasons:
1. The workpiece is not clean in the pretreatment or stays for too long after pickling.The pretreatment process of the workpiece should be strengthened to improve the pretreatment quality of the workpiece surface; the workpiece should be placed in the electroless nickel plating solution within 30s after pickling.
2. The pH value of the plating solution is too high or the loading amount is too large, and the deposition rate of the coating is too fast. The pH value of the plating solution should be appropriately lowered or the loading amount should be reduced.
3. The components of the plating solution are deteriorated or aged, resulting in the deposition rate of chemical nickel being too fast to be controlled, and the plating solution can only be scrapped.
4. There are suspended insolubles in the plating solution, which leads to the inclusion of impurities in the plating layer and causes pinholes. The bath should be filtered to remove impurities.
5. The plating solution is contaminated by metal impurities. The bath should be treated to remove metallic impurities.For substrates containing elements such as Pb, Cd, Zn, Sn, etc., a primer layer of nickel should be plated before plating to prevent harmful impurities from entering the plating solution.
6. The plating solution is contaminated by organic impurities. The plating solution should be treated with activated carbon and filtered to remove impurities.
Therefore, we need to pay attention to the above 6 points in the production process of using medium-phosphorus electroless nickel plating solution, which can effectively avoid the phenomenon of pinholes in the coating of the workpiece and reduce the occurrence of failures.