The characteristic and kinds of PCB surface finishing

As for human living environment asks is ceaseless rise, currently involved in the process of PCB production environment problem is particularly prominent.At present about lead and bromine is one of the hottest;Utilizing and halide will influence the development of PCB board in many ways.Although for now, the change of the PCB surface treatment technology and is not very big, still more distant things like, but should notice: long-term slow change will result in great changes.In the case of environmental protection calls for more and more high, the surface of the PCB process changes will happen in the future.
Surface treatment for the purpose of surface treatment of the most basic purpose is to guarantee good weldability or performance.Due to the nature of copper in air tend to exist in the form of oxide, is unlikely to keep to the original copper for a long time, so you need to other copper processing.While in the later assembly, strong flux can be used to remove most of the copper oxide, but strong flux itself is not easy to remove, so the industry generally don't use strong flux.
Common five kinds of surface treatment technology now has a lot of PCB surface treatment technology, common is hot air leveling（HASL), organic coating, electroless nickel/immersion gold(ENIG), immersion silver and tin the five kinds of craft.Because the PCB production  and material cost and process, so the different pcb design will use the different surface finishing. The cheap electronics  and simple products, we will use HASL or OSP, but for the expensive and high-density electronics products, we will use the immersion gold or silver, the pcb cost will higher, but it will better for components assembly.