China Halogen-free PCB is a Copper clad panels with chlorine (C1) and bromine (Br) content less than 0.09% Wt (weight ratio) are defined as halogen-free copper clad panels, i.e. PCB halogen-free substrates. Halogen-free PCB Made in China.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.