HALOGEN-FREE FLAME RETARDANT HIGH TEMPERATURE MATERIALS FOR LEAD-FREE SOLDERING APPLICATIONS
Authors: Jay Amarasekera, Bo Liu, Herve Cartier and Alexis Company: GE Industrial, Plastics Date Published: 9/12/2006
Medical Electronics Symposium
Abstract: The recent push for environmentally friendly halogen-free and lead-free products has resulted in significant changes in the design of polymeric materials used in the electronics industry. The new products are required to be halogen and red phosphorus free, exhibit improved flame retardant properties, and withstand peak reflow temperatures of 235°C to 260°C. The polymer composites described in this study are made from polyphenylene sulfide (PPS), polyphenylene oxide (PPO), Polyphthalamides (PPA) or their blends. They offer inherent hydrolytic stability, excellent flame retardancy (UL-94 V0), high flow suitable for small connecter type applications and heat resistance above 260°C, compatible with the new soldering processes. The new flame retardant technology utilized makes it possible to design halogen-free and red-phosphorus-free products for electronics applications. The flame retardant glass-fiber reinforced PPA composites have high ductility for connector contact assembly, UL-94 V0, and a comparative tracking index of above 450V. The flame retardant glass-fiber reinforced polyamides passed the glow wire ignition test at temperatures high than 775°C. Radiation boosts the short-term thermal stability of crosslinkable polyamides at temperatures up to 350°C, which makes them suitable for lead-free soldering applications. Key words: lead-free soldering, halogen-free flame retardant, high temperature thermoplastics, PPA, PPO, PPS, radiation cross-linking.