Uneven current distribution: In the electroplating process, uneven current distribution is one of the main causes of uneven plating.
Author: Robby
The reasons for uneven plating in the process of electroplating hanging plating mainly include the following aspects:
Uneven current distribution: In the electroplating process, uneven current distribution is one of the main causes of uneven plating. Due to the edge effect of the current, the power line is easy to concentrate in the position of large curvature such as the sharp corners and edges of the parts, resulting in higher current density in these areas, and the thickness of the plated layer is greater than the average thickness; while in the middle of the surface due to the smaller curvature, the power line distribution is less, the current density is small, and the thickness of the plated layer is less than the average thickness.
Workpiece surface area differences: uneven size of different work areas (mixed degree) will also lead to uneven plating. In the same furnace mixed plating surface area differences in the workpiece, the area of small products with high current, thick plating, while the area of large products relative current density is small, thin plating.
Poor contact of hangers: Poor contact of some hangers will lead to small current actually allowed to pass, thus affecting the uniformity of the plated layer. Good conductive contact on the mounting device on the thick layer, while poor conductive on the mounting device on the thin layer.
Plating Time Differences: Differences in plating time also affect the thickness of the plated layer. The plating time is long the plating layer is thick, plating time is short the plating layer is thin.
Plating solution composition and temperature control: plating speed and temperature, pH and composition of the plating solution and other factors. Inconsistency in the control of these factors can lead to uneven thickness of the plated layer. Stirring plays an important role in obtaining a uniform coating, but it is difficult to fully control these factors in practice.
Anode plate problem: When the anode plate is impure, impurities will form a black film on the surface of the anode plate, affecting the quality of the plating solution and leading to rough and uneven plating.
Substrate material roughness: When the substrate material is rough, it leads to uneven plating.
To solve these problems, the following measures can be taken:
Optimize the design of the hangers: Make sure that the position and direction of the workpiece in the hangers can make the current evenly distributed.
Adjust the current density: Selecting the optimum current density can significantly affect the distribution of the plated layer.
Use dynamic agitation or circulation systems: Maintain dynamic agitation or circulation of the plating solution to avoid stratification of the plating composition in the bath and to ensure uniformity of the plating composition and temperature.
Regularly test and adjust the composition of the plating solution: Ensure the performance of the plating solution is stable.
Control the plating time: precisely control the plating time to avoid uneven thickness of plating layer caused by time difference.
Improve the surface treatment of the base material: reduce the roughness of the base material to improve the uniformity of the plating layer.
Through these measures, the problem of uneven plating layer in the process of electroplating hanging plating can be effectively improved, and the product quality can be improved.