Flame Retardant Materials for Electronic Connectors

Flame retardant materials are crucial for safety in aerospace, automotive, railway, and electronics sectors. The use of photopolymer additive manufacturing has been a strong focus in these industries in recent years due to its ability to produce high detail components with excellent surface finish. Arkema has developed a novel materials strategy for the creation of flame retardant resins that exhibit low viscosity, high printing resolution, high temperature resistance, and are halogen free. These resins can be manipulated to cover a range of material properties such as snap fit and dielectric properties while maintaining flame retardance. The materials achieve UL-94 V0 ratings at thicknesses less than 1mm. A specific use case is demonstrated for printing compact, high-resolution, high-temperature connector assemblies. These fine feature parts are shown to be printable on multiple platforms, including LCD, DLP, and large format SLA systems. These materials also perform well under standard interconnect processing conditions requiring solder reflow without deleterious effects to form or to the performance of mounted connector assemblies. We will present our findings on the behavior of printed resin bodies, compared to traditionally molded thermoplastic bodies (typically a liquid crystalline polymer), as these assemblies are subjected to Pb-free solder reflow conditions. These reflow processes are guided by IPC J-STD-001 and -002 standards. Specifically, these findings will disclose coplanarity of the assembly pre- and post-reflow, and temperatures the bodies experience throughout solder reflow to reveal the temperature resistance of this printed resin, thus enabling wider adoption of AM throughout the electronics industry.