According to the JPCA - ES - 01-2003 standard: chlorine (C1), bromine (Br) is less than 0.09% Wt (weight ratio) of the copper clad, defined as halogen-free copper clad. (at the same time, the CI + Br total 0.15% or less [1500 parts per million]).
Halogen, refers to the chemical halogen elements in the periodic table, including fluorine (F), chlorine (CL), bromine (Br), iodine (I). At present, the flame retardant base material, FR4 and CEM - 3, flame retardants for brominated epoxy resin. Brominated epoxy resin, tetrabromobisphenol A, aggregation, polybrominated biphenyl, polymerization polybrominated diphenyl ether, polybrominated diphenyl ether is the main resistance of copper clad fuel, its cost is low, compatible with epoxy resin. But research shows that institutional containing halogen flame retardant materials (polymerization polybrominated biphenyl PBB: polymerization polybrominated diphenyl ether PBDE), waste burning, emit two well English (dioxin dioxin TCDD), benzene furan (Benzfuran), such as large amount of smoke, smelled, highly toxic gas, carcinogenic, unable to discharge after intake, not environmental protection, affect human body health. As a result, the eu has launched the ban on electronic information products to PBB, PBDE as flame retardant. China's ministry of information industry the same documents, to July 1, 2006, the market of electronic products not contain lead, mercury, hexavalent chromium, aggregation.
European Union law banning the use of PBB and PBDE of six kinds of material, we have learned, PBB and PBDE in copper clad industry has basically not in use, is widely used in addition to the PBB and PBDE of bromine flame retardant materials, such as four bromine double phenol A, two bromophenol, etc., its chemical formula is CISHIZOBr4. This kind of bromine flame retardants of copper clad no laws and regulations to regulation, but this kind of bromine type copper clad, burning or electrical fire, can release a large number of toxic gases (bromide), large amount of smoke; The PCB as hot the whole peaceful element, when welding the plank affected by high temperature (> 200), also can release tiny amounts of hydrogen bromide; Whether also can produce dioxins, is still under evaluation. Therefore, containing flame retardant tetrabromobisphenol A FR4 board, current law has not been banned, you can also use, but can not be called A halogen-free plank.
Due to the use of P or N to replace halogen atoms and to a certain extent reduce the polarity molecular bonds of epoxy resin, thus improve the quality and the insulation resistance of the wear ability
Halogen free plate because of the nitrogen and phosphorus is also oxygen resin of N and P in fox for electronic halogen relatively less, with the probability of the water hydrogen atoms to form hydrogen bonds than halogen material, so the absorbent material is lower than conventional halogen flame retarding material. For plate, low water absorbability to improve the reliability and stability of the material has a certain impact.
Halogen-free plate is greater than the content of nitrogen and phosphorus in ordinary phosphorus-containing material halogen content, molecular weight and its monomer as well as Tg values are increased. In the case of heat, its molecular motor ability will be lower than the conventional epoxy resin, thus the halogen free material thermal expansion coefficient is relatively small.
Halogen free PCB due to have low water absorption and adapt to the requirements of environmental protection, also in other performance can meet the quality requirements of the PCB board, therefore, halogen-free, already more and more demand for PCB; Another big plate suppliers in halogen-free, substrate and halogen-free, PP also spent more money on research and development, believe that before long, low price of halogen-free, plating, will immediately put into market. All the PCB manufacturer should, therefore, the halogen-free plank to try and use on the agenda, to develop a detailed plan, gradually expand the occupancy of halogen-free plate in our factory, make oneself marched at the head of the market demand