Electroplating is the process of plating a thin layer of other metals or alloys on the surface of some metals by using the electrolysis principle. It is a process of attaching a layer of metal film to the surface of metal or other materials to prevent metal oxidation (such as corrosion), improve wear resistance, conductivity, light reflection, corrosion resistance (copper sulfate, etc.) and enhance aesthetic appearance. The outer layer of many coins is also plated. Using electrolytic cell principle to deposit metal coating with good adhesion but different properties and matrix materials on mechanical products. The electroplated layer is uniform and generally thinner than the hot dip layer, ranging from several microns to several tens of microns. Through electroplating, decorative protective and various functional surface layers can be obtained on mechanical products, and worn and faulty workpieces can also be repaired.
In addition, it has different functions according to various electroplating requirements. Examples are as follows:
1. Copper plating: priming to improve the adhesion and corrosion resistance of the electroplated layer. (Copper is easy to oxidize. After oxidation, verdigris will no longer conduct electricity, so copper plated products must be protected by copper.)
2. Nickel plating: used as primer or as appearance to improve corrosion resistance and wear resistance (chemical nickel is more wear resistance than chrome plating in modern technology). (Note that many electronic products, such as DIN head and N head, no longer use nickel as backing, mainly because nickel has magnetism, which will affect passive intermodulation in electrical performance)
3. Gold plating: improve conductive contact impedance and signal transmission. (Gold is the most stable and expensive. )
4. Palladium and nickel plating: improve conductive contact impedance, enhance signal transmission, and wear resistance is higher than gold.
5. Tin-plated lead: improves welding ability and is quickly replaced by other substitutes (since lead is now mostly replaced by bright tin and fog tin).
6. Silver plating: improve conductive contact impedance and signal transmission. (Silver has the best performance, is easy to oxidize, and conducts electricity after oxidation)
Electroplating is a method that uses the principle of electrolysis to lay a layer of metal on the conductor.
In addition to electrical conductors, electroplating can also be used on specially treated plastics.
The electroplating process is basically as follows:
Coating metal on anode
The substance to be plated is on the cathode
The cathode and anode are connected by an electrolyte solution consisting of positive ions of plated metal
When a direct current power supply is applied, the metal of the anode will oxidize (lose electrons), while the positive ions in the solution will be reduced (get electrons) at the cathode to form atoms and accumulate on the cathode surface.
The beauty of the electroplated object after electroplating is related to the current. The smaller the current, the more beautiful the electroplated object will be. On the contrary, some uneven shapes will appear.
The main uses of electroplating include preventing metal oxidation (such as corrosion) and decorating. The outer layer of many coins is also plated.
Sewage from electroplating (such as useless electrolyte) is an important source of water pollution. Electroplating process has been widely used in semiconductor and microelectronic component lead frame process.
VCP: Vertical Continuous Electroplating, a new type of machine used for circuit boards, has better quality than traditional hanging electroplating.