Influence of the pumping system on plating
Author: Robby
The impact of the pumping system on plating is mainly reflected in the impact on the plating solution and the impact on the electroplating two aspects. First of all, the influence of pumping system on plating solution is mainly reflected in the oxidizing effect on divalent tin ions. In the process of electroplating pure tin, pumping will cause the dissolved divalent tin ions to over-oxidize to tetravalent tin, which even in a solution with a high acid concentration will form Sn(OH)4 with very low solubility, and after losing one molecule of water will generate a colloidal suspension of stannic acid (H2SnO3), leading to turbidity of the bath solution, which will affect the quality of the plating layer.1 This suggests that pumping systems need to be used carefully to avoid causing damage to the electroplating bath. to avoid adverse effects on the plating solution.
Secondly, the influence of the pumping system on the electroplating is mainly reflected in the influence on the surface morphology, structure, hardness and corrosion resistance of the electroplating. Under different air pressure conditions, the coating properties and structure of vacuum electroplating will change significantly. As the air pressure decreases, the surface particle size and surface flatness of the electroplated film will increase, because the air pressure decreases so that the number of air molecules between the particles forming the electroplated film decreases, resulting in slower film formation, aggregation and growth of particles, which leads to an increase in the size of the surface particles. At the same time, the decrease in air pressure makes the crystal structure of the electroplated film become denser and more uniform, which improves the hardness and corrosion resistance of the electroplated film. The electroplated coatings prepared in a salt water environment at an air pressure of 0.5 Pa showed the best corrosion resistance.2 This suggests that the plating process can be optimized by controlling the use of the pumping system to improve the quality and performance of the coatings.
In summary, the influence of the pumping system on electroplating is multifaceted, including both the effect on the plating solution and the effect on the electroplated coating. Therefore, careful operation is required when using the pumping system in order to avoid adverse effects on the plating process.