This article discusses the processing characteristics of halogen-free printed boards and some experience in the processing process.įor now, most of the halogen-free materials are mainly phosphorus-based and phosphorus-nitrogen-based. Therefore, FR4 sheets containing tetrabromobisphenol A flame retardant are not currently prohibited by law and can still be used, but they cannot be called halogen-free sheets.
When the PCB is leveled with hot air and components are soldered, the plate is affected by high temperature (>200), and a trace amount of hydrogen bromide will be released whether it will also produce dioxins is still under evaluation. This type of copper clad laminate containing bromine as a flame retardant is not regulated by any laws and regulations, but this type of bromine-containing copper clad laminate will release a large amount of toxic gas (brominated type) and emit a large amount of smoke during combustion or electrical fire.
The chemical formula of bisphenol A, dibromophenol, etc. It is understood that PBB and PBDE are basically no longer used in the copper clad laminate industry, and bromine flame retardant materials other than PBB and PBDE, such as tetrabromide, are mostly used. The EU law prohibits the use of six substances including PBB and PBDE. The Ministry of Information Industry of China also requires that as of July 1, 2006, electronic information products put on the market must not contain substances such as lead, mercury, hexavalent chromium, polybrominated biphenyls or polybrominated diphenyl ethers. Therefore, the European Union initiated the prohibition of using PBB and PBDE as flame retardants in electronic information products. Large amount of smoke, unpleasant smell, highly toxic gas, carcinogenic, can not be discharged after ingestion, not environmentally friendly, and affect human health. However, studies by related institutions have shown that halogen-containing flame-retardant materials (Polybrominated Biphenyls PBB: Polybrominated Diphenyl Ethyl PBDE) will emit dioxin (dioxin TCDD), benzofuran (Benzfuran), etc. They have low cost and are compatible with epoxy resins. Among the brominated epoxy resins, tetrabromobisphenol A, polymeric polybrominated biphenyls, polymeric polybrominated diphenyl ethers, and polybrominated diphenyl ethers are the main fuel barriers for copper clad laminates. At present, flame retardant substrates, FR4, CEM-3, etc., flame retardants are mostly brominated epoxy resin. Halogen refers to the halogen elements in the periodic table of chemical elements, including fluorine (F), chlorine (CL), bromine (Br), and iodine (1). (At the same time, the total amount of CI+Br≤0.15%) TU-862T laminates also exhibit superior chemical resistance, thermal stability for lead free soldering assembly and CAF resistance than conventional High Tg materials.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.
These products are suitable for boards that need to survive severe thermal cycles, or to experience excessive assembly work.
#Halogen free pcb series
This series of green materials are designed to eliminate the use of halogenated resins due to the potential hazardous effects from the environmental concerns. TU-862T is also available for single/double sided application. TU-862P T is designed for use with TU-862T for making multilayer printed wire boards. The materials are compatible with the AOI process and exhibit the UV-block characteristic. Unlike conventional FR-4 material using brominated resin as flame retardant, TU-862T /TU-862P T achieves flammability class of UL94V-0 by incorporating phosphorus and nitrogen compounds in the materials. TU-862T High Tg halogen free materials are made of High Tg epoxy resin and E-glass fabric.
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