Novel polyphenylene sulfide resin for high-frequency copper-clad laminates with low dielectric tangent and flame retardancy

We report a novel poly(2,6-dimethyl-1,4-phenylene sulfide) resin bearing vinyl groups (PMPS-V) designed for next-generation copper-clad laminates used in high-frequency applications. Oligo(2,6-dimethyl-1,4-phenylene ether) resins are commonly used owing to their low dielectric constant and high thermal resistance; however, further reduction in dielectric loss tangents is needed for future communication networks. Materials with excellent dielectric properties typically exhibit low polarity and high flammability, presenting a trade-off between dielectric performance and flame retardancy. PMPS-V exhibits thermosetting behavior and an extremely low dielectric-loss tangent (<0.001 at 10 GHz). Owing to its polyphenylene sulfide backbone, PMPS-V meets the UL-94 V-0 flame retardancy standard. Long-term heat resistance testing at 150°C confirmed minimal degradation in dielectric properties, demonstrating excellent thermal stability. In addition, PMPS-V has a high glass transition temperature and favorable solubility in common solvents such as toluene, making it suitable for printed wiring board applications. These results indicate that PMPS-V is a promising candidate for next-generation low dielectric materials. • Thermosetting polyphenylene sulfide (PPS) with substituents • Exhibits a low dielectric loss tangent and high flame retardance • Low dielectric loss tangent after prolonged heat resistance test • Compatible with solvent solubility and other resins, creating printed wiring boards