If you want to produce circuit boards that do not contain halogen elements, you need to start with the raw materials. According to the JPCA-ES-01-2003 standard, copper clad boards with chlorine (C1) and bromine (Br) content less than 0.09% Wt (weight ratio) are defined as halogen-free copper clad boards. (Meanwhile, the total amount of CI+Br is ≤ 0.15% [1500PPM]).

　　So why ban brine? Halogens refer to halogen elements in the periodic table of chemical elements, including fluorine (F), chlorine (CL), bromine (Br), and iodine (1). At present, flame retardant substrates such as FR4 and CEM-3 are mostly brominated epoxy resins as flame retardants. In brominated epoxy resin, tetrabromobisphenol A, polybrominated biphenyls, polybrominated biphenyl ethers, and polybrominated diphenyl ethers are the main blocking fuels for copper clad laminates, with low cost and compatibility with epoxy resin. However, research by relevant institutions has shown that flame retardant materials containing halogens (polybrominated biphenyl (PBB): polybrominated biphenyl ether (PBDE)) will release dioxin (TCDD), benzofuran (Benzfuran), and other pollutants during waste ignition and combustion. They emit a large amount of smoke, have an unpleasant odor, are highly toxic gases, carcinogenic, cannot be discharged after ingestion, are not environmentally friendly, and affect human health. Therefore, the EU has initiated a ban on using PBB and PBDE as flame retardants in electronic information products. The Chinese Ministry of Information Industry also requires that electronic information products put into the market must not contain substances such as lead, mercury, hexavalent chromium, polybrominated biphenyls, or polybrominated biphenyl ethers, starting from July 1, 2006.