Halogen-Free Flame Retardants for PWBs: Challenges and Opportunities

摘要

Tetrabromobisphenol-A (TBBPA) is the principal flame retardant used in printed wiring boards (PWBs). Mineral and phosphorus-based alternatives continue to be of interest. Additive-type flame retardants, such as aluminum trihydroxide, and reactive-type flame retardants, such as organophosphorus compounds, have been offered to impart flame retardancy to prepregs and laminates used in the construction of printed wiring boards. Flammability testing and economic considerations suggest that these alternatives are not yet direct replacements for TBBPA; formulation modifications will be required to meet the technical and financial objectives. Some possible improvements to the cost/flammability challenge have been identified, but further progress is needed.