Analysis and Prevention of Plating Copper Faults
The use of copper plating process with electroplating has become increasingly widespread in China. Copper plating mainly uses copper sulfate as the plating bath. This can play a very important role in the plating process, including protection, decoration and other purposes. However, some wrong operations and improper maintenance of the process can lead to fault of copper plating.
Analysis of copper plating fault:
1. Oxide
When copper surface is oxidized, it will form a copper oxide film. The copper oxide film formed in the copper plating process is called copper oxide film. At this time, there will be poor adhesion of the coating to the substrate due to the poor electrical conductivity of the film. The surface conductivity of the substrate is not uniform, resulting in local white crystals, changing the appearance of the surface.
2. Crater
The crater fault is the stay of the elastic particles such as powder particles blackening and pitting on the plated layer. This problem is mainly caused by the increase of the acidity of the plating bath, the accumulation of voids on the substrate, and the bubble movement of the plating liquid.
3. Matting
Matting is a kind of fault, which is easy to appear on the plated parts. Its main reason is that the temperature in the plating bath is too low or the current density is too high, leading to the deposition of large numbers of particles on the substrate during plating. These particles will scratch the surface of the substrate, resulting in matting.
4. Grain
Grain refers to a kind of plating surface uneven fault, which is mainly caused by too low current density or too much electroplating time. These two factors will cause coarse granules to be deposited on the substrate, which will make the surface of the plated parts become rough.
5. Peeling
Peeling is also a common fault in copper plating, which is mainly caused by the adhesion between the substrate and the plated parts. Poor adhesion of the plated parts will cause peeling.
Prevention methods for copper plating fault:
1. To prevent the oxidation state of copper plating, it is necessary to pay attention to the selection of copper sulfate and the control of electroplating current density. The current density of copper sulfate should be between 0.2 and 1.2A/dm2.
2. To prevent crater faults, it is necessary to pay attention to the cathodic current density control, the use of trickle method, and the addition of dry cells or circuit devices. At the same time, it is necessary to control the temperature of plating bath and the pH value of solution.
3. To prevent matting, it is necessary to pay attention to the selection of plating current density. The plating current density should not be too low or too high. The temperature of the plating bath should not be too low.
4. To prevent grain faults, it is necessary to control the current density and reduce the plating time. In addition, it is necessary to minimize mechanical filtering when plating liquid is transferred, and to use filter supplies while filtering dust and maintain the filter regularly.
5. To prevent peeling faults, it is necessary to control the current density, select the liquid with low viscosity, and increase the surface coverage of the plated parts. In addition, it is necessary to clean the plated parts before plating and maintain the adhesion of the plated parts.
In conclusion, the selection of plating process, the selection of plating bath, the control of current density, the maintenance and maintenance of the environment are all very important to prevent copper plating faults. With the correct operation and maintenance, it can greatly reduce the occurrence of copper plating faults and ensure the quality of plating.
