Plating relevant functions–make use of electrolysis to deposit of good adhesion of the article , but the performance of different materials and the base metal cladding techniques . Than the hot-dip plating layer having a uniform , generally thin, ranging from a few microns to tens of microns . By electroplating , you can get protective and decorative surface layer on the various functions of mechanical products , you can also repair wear and workpiece machining errors .
Moreover , there are different plating relevant functions according to the needs of variety of plating.
1, Copper plating: bottoming to enhance the plating layer adhesion, and corrosion resistance. ( Copper is easily oxidized, after oxidization, patina is no longer conductive, so copper electroplating products must be done copper plating protection.
2, Nickel electroplating: bottoming or for appearance to enhance corrosion resistance and wear ability, ( which is the modern process wear- ability more over than chrome plating) are no longer use nickel bottoming, mainly due to the nickel magnetic, which will affect the electrical performance of passive intermodulation.
3, Gold-plated: improving conductive contact resistance and enhance signal transmission. ( Gold is the most stable, but also the most expensive material. )
4, Palladium Nickel plating: improving conductive contact resistance, and enhance signal transmission, abrasion resistance is higher than gold.
5, Plating tin-lead: the ability to enhance welding, soon to be replaced by other alternative materials ( now mostly replaced by lead- tin -plated bright and matte tin).
6, Silver plating: to improve the conductive contact resistance and enhance signal transmission. (Silver has the best performance, but easily to be oxidized, and still can conduct after oxide).Electroplating is a method which using the principle electrolytic to cover a metal layer on conductive.
In addition to the conductive, plating also can be used for plastic cement after special handling.
The basic process of electroplating as follows:
Connected the plating metal on anode, while the be plated metal connected on cathode.
Connection between anode and cathode by connection by electrolyte solution composed by metal positive inos. Powered by DC current, the anode metal will be oxidized (loss of electrons), while positive ions in solution will reduction in cathode ( to obtain electron) and become atomic and accumulate on cathode surface.
After electroplating, the to be plated workpiece appearance related to current size, the smaller the current, the workpiece will be more beautiful appearance; otherwise it will appear a number of uneven shapes.
The main purpose of plating mainly including preventing of metal oxide ( e.g rust ) as well as decoration. The outer layer of coin is also a plating .
Waste water in plating process (e.g ineffective electrolyte) is the biges source of water pollution.
Plating technology process has been widely used in the semiconductor and microelectronics technology components of the lead frame.
VCP: vertical continuous plating, the new machine which circuit boards adopted is more better quality than traditional hanging plating.
Partially silver electroplating:
Aluminum plating solution formulation process:
High-temperature acid weak base etching → Rinse →Acid picking → Rinse→ Zincate →Rinse → Second zincating→ Rinse → Pre copper plating → Rinse → Rinse → Cyanide silver plating → Recycling rinse→ Rinse → Brightness dipping → Rinse → drying.
From the plating process we can tell, the material must be high temperature resistance ( about 80 ℃), alkali resisting, acid resisting, secondary, the protective material can be easily peeled off after the silver plating.