Sahin, Seckin, Niru K. Nahar, and Kubilay Sertel. "Permittivity and Loss Characterization of SUEX Epoxy films for mmW and THz Applications." IEEE Transactions on Terahertz Science and Technology (2018).
We present a systematic characterization of the dielectric permittivity and loss tangent of SUEX dry films for mmW and THz bands. Green and cured SUEX samples of varying thicknesses were studied using two complementary measurement techniques. First, the Nicolson-Ross-Weir technique was used in a 2-port TE10 waveguide environment for 90-140 GHz and 140- 220 GHz bands. The samples were also characterized using a transmission-mode time domain THz spectrometer over the 90 GHz-2 THz band. Real part of permittivity and loss tangent were measured to be 3.08 and 0.057, respectively for the green SUEX sample. Ultra-violet light curing reduces the permittivity and loss tangent down to 2.86 and 0.020, respectively. SUEX films can be easily laminated onto any substrate, eliminating the spin coating and long process optimizations that are required for conventional liquid resists. As such, SUEX is an easy-to-process alternative to commonly used epoxy-based resists, such as SU- 8, while exhibiting similar dielectric permittivity and material losses.
A commercial THz TDS system (TPS Spectra 3000 from TeraView, Inc.) was utilized to obtain the transmission coefficient measurements of the SUEX samples …
for full paper see https://ieeexplore.ieee.org/abstract/document/8365846/