The necessity of halogen-free solder paste

Electronic waste and plastic products containing bromine and chlorine compounds contain halogen flame retardants and PVC. When these products are discarded and burned, harmful substances such as dioxins and acidic gases (HCl) are easily produced, which can bioaccumulate and harm the environment and human health. The United Nations International Environmental Programme has listed them as persistent organic pollutants.

 

Halides are widely present in printed circuit boards, solder masks, molding compounds, connectors, and other common electronic products. The flame retardants in printed circuit boards contain halogenated materials, among which the toxicity of PBB and PBDE is the most concerning. Circuit boards and electronic products containing halogens can produce many by-products in incomplete combustion, including dioxins and furan compounds, as well as acidic or corrosive gases, which have potential hazards to the environment and human health. At present, most power and communication cables contain halogens, which emit toxic mist like chemicals when burned. Once a fire occurs, the acidic gases produced by the burning of cables will damage people‘s noses, mouths, and throats, and the smoke can easily cause people to lose their direction and find it difficult to escape the scene of the fire. Therefore, the EU‘s RoHS regulations prohibit the use of PBB and PBDE, two halogenated materials, in printed circuit boards. Some people are now attempting to restrict the use of all halogenated materials in electronic devices. They believe that when burning electronic devices, brominated materials will generate highly toxic dioxins. They requested a ban on the use of halogenated materials that exceeded the initial RoHS regulations that only restricted PBB and PBDE.

 

Halogen free materials may become another green revolution in the electronics industry since the implementation of the RoHS (Restriction of Hazardous Substances) directive on July 1, 2006. Compared to the hazards of halides, the hazards of the six hazardous substances restricted by the RoHS directive (lead Pb, cadmium Cd, mercury Hg, hexavalent chromium CR6+four heavy metals, and polybrominated diphenyl ether PBDE and polybrominated biphenyl PBB flame retardants) are even more alarming.