Poly-P-Xylene film for high temperature high voltage dielectric applications

Poly-P-Xylene (PPX), a high melting point polymer previously used as a dielectric in microelectronic circuits, was electrically characterized as a function of frequency, temperature and voltage to explore its possible use for high voltage high temperature space power applications. Properties that were measured included dielectric constant and dielectric loss both at frequencies up to 100 kHz, at several temperatures up to 200/spl deg/ C, and at electric fields up to 40 volt//spl mu/m. The ac and dc breakdown strength of the film were determined at temperatures up to 250/spl deg/ C. The results obtained displayed very little change in the dielectric constant, dielectric loss and breakdown voltages with an increase in temperature. At temperatures above 250/spl deg/ C, however, visual inspection of the tested samples revealed that the film became brittle and lost some of its physical integrity. The usefulness of PPX as a high temperature high voltage dielectric is demonstrated in this paper.