BROMIDE-FREE OPTIONS FOR PRINTED CIRCUIT BOARDS

BROMIDE-FREE OPTIONS FOR PRINTED CIRCUIT BOARDS

Flame retardants have been around since the Egyptians and Romans used alum to reduce the flammability of wood. Brominated flame retardants (BFRs) first experienced use after World War II as the substitution of wood and metal for plastics and foams resulted in materials that were much more flammable. The widespread use of BFRs initiated in the 1970s with the explosion of electronics and electrical equipment and housings. For the US market, all of these products must conform to the UL 94 flammability testing specifications. In fact, the most common printed circuit board (PCB) in the electronics industry, FR-4, is defined by its structure (glass fiber in an epoxy matrix) and its compliance to UL 94 V0 standard.To get more news about Isola 370HR PCB, you can visit pcbmake official website. However, at the same time BFRs saw increasing use, scientists began to detect increasing concentrations of these substances in the environment, food chain, and wildlife1. Additional research has expressed concern over the potential toxicity of BFRs and their potential for endocrine disruption. As a result, industries using these BFRs, including the textile and electronics industries, have been looking for alternatives to satisfy current (and in anticipation of new) bans and regulations controlling their use.fig 1-24 To date, researchers and environmentalists have identified several suspect BFRs, including poly-brominated biphenhyls (PBBs), penta-polybrominated diphenyl ethers, octa- polybrominated diphenyl ethers, and decapolybrominated diphenyl ethers (PBDEs). These BFRs are mostly irrelevant for the electronics industry as printed circuit boards (PCBs) and component moldings primarily use tetrabromobisphenol-A (TBBPA), with TBBPA accounting for 95-97% of all flame retardants in PCBs. The difference between TBBPA and the other BFRs is that TBBPA is reacted into the polymer backbone as opposed to being physically added. As such, studies and organizations such as the World Health Organization (WHO) have concluded that TBBPA poses a negligible risk to the general population. The chemical is currently not banned in any country and is not included in the European Union’s Restriction of Hazardous Substances (RoHS). However, several governments, organizations, and the general public do not differentiate among the many BFRs and have requested an overall elimination of these chemical compounds. There is even indication that in some countries and industries, OEMs who still use BFRs are losing market share2.