Characterization of thin film microstrip lines on polyimide

This paper presents an in depth characterization of thin film microstrip (TFMS) lines fabricated on Dupont PI-2611 polyimide. Measured attenuation and effective dielectric constant is presented for TFMS lines with thicknesses from 2.45-7.4 /spl mu/m and line widths from 5-34.4 /spl mu/m over the frequency range of 1-110 GHz. The attenuation is separated into conductor and dielectric losses to determine the loss tangent of Dupont PI-2611 polyimide over the microwave frequency range. In addition, the measured characteristics are compared to closed form equations for /spl alpha/ and /spl epsiv//sub eff/ from the literature. Based on the comparisons, recommendations for the best closed form design equations for TFMS are made.