Harm of Lead in PCBA Processing

Harm of Lead in PCBA Processing

PCBA processing is to connect various electronIC components on PCB board through surface mount (SMT), plug-in (DIP) and other electronIC assemblies. PCBA process flow mainly includes SMT, AOI, DIP, FCT testing and other processes. Due to the size difference of electronic components, there will be different processes and requirements in assembly and insertion. The assembly density of PCBA is relatively high, and the SMAll size and light weight of electronic products also have certain changes and requirements in mounting. The reliability, seismic resistance and excellent weldability of the products have high requirements for the hardware and software facilities of PCBA processing.

I. Hazards of lead

Lead has been used in various industries for more than 1000 years, and lead is used in PCB manufacturing. At present, the global annual consumption is about 5 million tons, of which 81% is used for batteries, followed by lead oxide white paint and weapons, both of which are also used for about 10%. They are the three places where large quantities of lead are used. In fact, only 0.49% of them are actually used in the circuit board manufacturing and electronic product welding industry. However, due to its wide distribution range and very difficult recovery and reuse, the pollution caused by them cannot be considered as serious! The harm of lead can be seen from this

Lead is the "killer" of cells. When the blood lead concentration reaches 15mg/100ml, it will cause children's growth retardation and mental retardation. The younger the age, the more serious the nerve damage. Lead poisoning is characterized by excessive movement, excitement, poor sleep, loss of appetite, frequent urination and enuresis, irritability, moodiness, and even poor hearing and language expression. The harm of lead is very terrible, so it is urgent to make the circuit board lead-free.

The harm of lead in PCBa blood

Lead compounds easily infiltrate into groundwater, which will become a potential crisis of drinking water. Taking Japan as an example, its environmental protection regulations require that the lead in groundwater should not exceed 0.3 ppm (0.3 mg/l). As for the United States, in its EPA40 CFR141, it is stipulated that the lead content in drinking water is more strict to a limit of only 15 ppb (0.015mg/l). For example, according to the TCLP poison dissolution test in EPA 40 CFR261 of the United States Environmental Protection Agency, the maximum dissolution amount of lead can only be analyzed to 5mg/l, while the loss amount of lead in various solder joints in general circuit board manufacturing after abandonment in the nature is hundreds of times higher than that in the above dissolution test. How can the danger of lead be so dangerous that it can not be feared carefully! So it is imperative to make circuit boards in electronic products lead-free.