In PCB production, technology is an extremely important link. General processes include OSP, gold deposition, gold plating, tin spraying, etc. As the most common process in PCB production, tin spray is not new to everyone. In tin spray process, there are two kinds: “lead” and “lead-free”. What is the relationship between them? What’s the difference? Let’s have a deep steak today.
1、 History of development
“Lead-free” is developed and evolved on the basis of “lead”. Since the 1990s, the United States, Europe, Japan and other countries have legislated on the application restrictions of lead in industry, and conducted research on lead-free welding materials and development of related technologies.
2、 Performance difference
The melting point of lead-free process is 218 degrees, while the melting point of lead spray tin is 183 degrees. The solderability of lead-free solder is higher than that of lead solder. The lead process is relatively poor in firmness and prone to faulty welding. However, due to the relatively low temperature of lead, the thermal damage to electronic products is smaller, and the PCB surface is brighter.
2. Cost variance
In the lead-free process, the cost of solder strip used in wave soldering and solder wire used in manual soldering increased by about 3 times, while the cost of solder paste used in reflow soldering increased by about 2 times.
Lead, as a toxic substance, is harmful to human health and environment.
Even though the lead process has the characteristics of low price and brighter surface, under the pressure of policy and environmental protection in recent years, the living space of lead is becoming smaller and smaller. The main reasons are the sewage discharge of PCB lead process and the disposal of lead PCB products by burying or burning. The lead composition will eventually return to the environment through the media, resulting in serious Lead pollution brings great harm to the environment and human survival.
With the enhancement of the awareness of environmental protection in China, the Chinese government has also promulgated relevant laws and regulations on this matter, and started to levy environmental taxes on various enterprises, showing the determination of the state to “adjust the structure and promote the transformation”. In addition, foreign countries have also issued relevant laws and regulations. After the implementation of the EU environmental protection directive, if it fails to pass the EU certification, it means that it cannot enter the European market, thus losing its market share in Europe.
With the promulgation of relevant policies and regulations at home and abroad, many PCB factories in China are unable to bear the burden of closing down. The implementation of lead-free technology is a huge challenge for PCB factories, facing the dual test of enterprise quality and technical strength. The good operation of lead-free technology is not only the simple replacement of lead-free production equipment, but also involves the quality of employees, quality management and other aspects, and directly increases the production cost.
On the road from lead to lead-free, agile PCB has strengthened innovation in energy conservation and emission reduction, comprehensively used “big data” and “cloud computing”, improved resource utilization, realized automatic management and monitoring of production lines, and made development while also protecting the environment.
This is also inseparable from the support of the government. In Anhui Guangde PCB Industrial Park, the location of jiepei factory, the Guangde government fully considered the pollution prevention problem, and carried out centralized control and treatment of pollutants such as sewage and solid waste generated in the production process of the enterprise. After several years of development, Guangde PCB industry has formed a unique “Guangde mode”. At present, there are PCB sewage treatment plant, PCB solid waste center, PCB water intake plant and other supporting projects, upgrading environmental protection from “important work” to “lifeline”,
Only by realizing the ecological advantages, PCB enterprises can improve their core competitiveness, and only by continuous innovation, can PCB industry meet the hard target of environmental protection more efficiently and more quickly, and finally reduce the operating costs of enterprises. PCB industry can move forward with light installation only when the burden of environmental protection is removed. Therefore, it is the general trend for PCB enterprises to abandon the “lead” technology.