A biobased low dielectric resin derived from vanillin and guaiacol

Abstract

A new biobased low dielectric resin derived from vanillin and guaiacol has been synthesized. Thanks to the low polarizability of hexafluorocyclobutyl units, this resin exhibits good dielectric properties with an average dielectric constant (D_k) of 2.67 and a dielectric dissipation factor (D_f) of 2.9 × 10⁻³ at a frequency range from 0.15 MHz to 20 MHz. This resin also displays high dimensional stability with a coefficient of thermal expansion (CTE) of 46.3 ppm per °C from 25 °C to 180 °C and a glass transition temperature (T_g) of 243 °C. In addition, the polymer films on the silicon wafers also exhibit good uniformity, flatness, and high hydrophobicity, suggesting that this bio-based resin is suitable as an encapsulation for applications in the microelectronic industry.