The probability of forming hydrogen bonds with hydrogen atoms in water is lower than that of halogen materials, so the water absorption of the material is lower than Conventional halogen-based flame retardant materials.įor the board, low water absorption has a certain impact on improving the reliability and stability of the material. The halogen-free sheet material has fewer electrons than halogens in the nitrogen-phosphorus-based oxygen reduction resin. The polymer resin containing phosphorus and nitrogen compounds generates incombustible gas when burned, which helps the resin system to be flame-retardant.ĭue to the use of P or N to replace the halogen atoms, the polarity of the molecular bond segment of the epoxy resin is reduced to a certain extent, thereby improving the qualitative insulation resistance and resistance to breakdown. When phosphorous resin is burned, it is decomposed by heat to generate meta-polyphosphoric acid, which has strong dehydration property, so that a carbonized film is formed on the surface of the polymer resin, which insulates the burning surface of the resin from contact with air, extinguishes the fire, and achieves a flame-retardant effect. Phosphorus and phosphorus and nitrogen are the mainstays. The use of halogen as a raw material has huge negative consequences and it is necessary to ban halogen. Large When the PCB is leveled with hot air and PCB components are soldered, the board is affected by high temperature (>200), and a small amount of hydrogen bromide will be released whether it will also generate toxic gas is still under evaluation. The chemical formula is CISHIZOBr4.Īlthough this type of copper clad laminate containing bromine as a flame retardant is not regulated by any laws and regulations, this type of bromine-containing copper clad laminate will release a large amount of toxic gas (brominated type) and smoke during combustion or electrical fire. Bromine flame-retardant materials other than PBB and PBDE, such as tetrabromobisphenol A, dibromophenol, etc., are mostly used. It is understood that PBB and PBDE are basically no longer used in the copper clad laminate industry. The Ministry of Information Industry of China also requires that electronic information products put on the market must not contain substances such as lead, mercury, hexavalent chromium, polybrominated biphenyls or polybrominated biphenyl ethers.
Therefore, the law prohibits the use of six substances including PBB and PBDE.
when they are discarded and burned, causing a large amount of smoke and a difficult smell Smell, there is a highly toxic gas, which is carcinogenic, and cannot be discharged after being ingested by the human body, which seriously affects health. Halogen-containing flame-retardant materials (Polybrominated biphenyls PBB: Polybrominated biphenyl ethers PBDE) will emit dioxin (dioxin TCDD), benzene furan (Benzfuran), etc. At present, the halogen-free, flame-retardant substrates required by PCBs, such as FR4, CEM-3, etc., are mostly brominated epoxy resins. Refers to the halogen elements in the periodic table of chemical elements, including fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Halogen-free materials include: TUC's TU883, Isola's DE156, GreenSpeed series, Shengyi's S1165/S1165M, S0165 and so on. (At the same time, the total amount of CI+Br≤0.15%) Among the halogen-free PCB substrates: According to the JPCA-ES-01-2003 standard: Copper clad laminates with chlorine (C1) and bromine (Br) content less than 0.09% Wt (weight ratio) are defined as halogen-free copper clad laminates.
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