A bio-based low dielectric material at a high frequency derived from resveratrol

Abstract

A new bio-based low dielectric precursor derived from resveratrol has been successfully synthesized via a facile two-step reaction. This precursor contained thermo-curing benzocyclobutene groups and was treated at a temperature of above 190 °C to form a crosslinked network, which showed a dielectric constant (D_k) of 2.69 and a dielectric loss (D_f) of 8.4 × 10⁻³ at a high frequency of 5 GHz. In particular, even after being immersed in boiling water for 5 days, the resin still maintains a low D_k value of 2.68 and a D_f value of 8.5 × 10⁻³. Such data are much better than those of the resveratrol-based epoxy resin (D_k value of above 3.5) and are comparable to those of a widely used commercial benzocyclobutene-containing low dielectric resin (DVS-BCB from Dow Chemicals). The cured precursor also exhibits high thermostability with a 5% weight loss temperature (T_d5) of 431 °C. Moreover, the crosslinked network exhibits a low water uptake of 0.17% even after immersing the precursor in boiling water for 5 days. These results indicate that the bio-based low dielectric precursor is suitable as an encapsulation resin for application in the microelectronic industry.