Why should PCB ban halogen

　　Halogen: Halogen elements in the periodic table of chemical elements, including fluorine (F), chlorine (Cl), bromine (Br), iodine (I). At present, flame retardant substrates, FR4, CIM-3, etc., and flame retardants are mostly brominated epoxy resins. Studies by relevant institutions have shown that halogene-containing flame retardant materials (polymerized polybrominated biphenyls PBB: Polybrominated diphenyl ether PBDE (PBDE), when discarded and burned, will release dioxin Dioxin TCDD, Benzfuran (Benzfuran), etc., large smoke, odor, highly toxic gas, carcinogenic, can not be discharged after human intake, seriously affecting health. Therefore, the EU law prohibits the use of six substances such as PBB and PBDE. The same document of China's Ministry of Information Industry requires that electronic information products put on the market cannot contain lead, mercury, hexvalent chromium, polybrominated biphenyls or polybrominated diphenylethers and other substances. It is understood that PBB and PBDE are basically no longer used in the copper clad plate industry, and more brominated flame retardant materials other than PBB and PBDE are used, such as tetrabromobisphenol A, dibromophenol, etc., whose chemical formula is CISHIZOBr4. Although there are no laws and regulations to regulate this kind of brominated copper clad plate as flame retardant, this kind of brominated copper clad plate will release a large amount of toxic gas (brominated type) when burning or electrical fire, and the smoke is large; When the PCB is used for hot air conditioning and component welding, the plate is affected by high temperature (>200), and a trace amount of hydrogen bromide will also be released; Whether it will also produce toxic gases is still being evaluated. To sum up, the negative consequences of halogen as a raw material are huge, and it is necessary to ban halogen.