A Norbornene-Networked Epoxy System Featuring Enhanced Thermal and Dielectric Performance as Advanced Electronic Materials

The escalating requirements of high-frequency wireless communication and advanced semiconductor packaging necessitate the development of polymeric materials with superior thermal stability and low dielectric loss. In this work, we present the development of a norbornene (NB)-derived epoxy system, synthesized using 5-Ethylidene-2-norbornene (ENB) and phenol as the key staring materials. The resulted ENB-phenol diglycidyl ether (ENBDE) was then cured with conventional commercial bisphenol-A (BPA) diglycidyl ether (DGEBA) epoxy resin at various ratios (ENBDE-DGEBA). Owing to the intrinsically rigid, low-polarity cyclic structure of NB, the introduction of ENBDE into the DGEBA results in the thermosets with significantly improved thermal resistance (glass-transition temperatures exceeding 230°C), excellent thermo-oxidative stability, and exceptionally decreased dielectric loss (~0.0064 at 10 GHz). These standalone properties, combined with favorable moisture resistance and good mechanical property, identify this newly designed ENBDE polymer can be used as a highly promising electronic material for next-generation high-frequency and high-speed electronic applications.