Low dielectric polymers at high frequency with bulky adamantane groups as the linker

Abstract

Two monomers with adamantane units as the linker and benzocyclobutene (BCB) groups as the crosslinking units have been successfully synthesized, and they are thermally treated to form polymers with a 5% weight loss temperature of up to 478 °C and a glass transition temperature of more than 350 °C. Among the polymers, the one containing fluorobenzene units displays a dielectric constant (D_k) of 2.58 and a dielectric loss (D_f) of 1.94 × 10⁻³ at a frequency of 10 GHz. Such a fluoro-containing polymer also exhibits a water uptake of 0.12% even when immersing it in boiling water for 72 h. These results demonstrate that the two polymers are suitable as low dielectric materials for application in the fabrication of devices used in high-frequency communication.