Enhanced Dielectric Breakdown Reliability of Glass with Polymer Coating

Low-alkali boroaluminosilicate glasses have attracted increasing attention in high-temperature dielectric applications due to their excellent dielectric, mechanical, and thermal properties. While the breakdown strength could be enhanced by reducing alkali concentration, we demonstrate an effective approach to improve the breakdown reliability of these low-alkali glasses by selectively coating a thin layer of polymers on anodes. It is shown that the dielectric breakdown of the glasses is dominantly determined by the magnified electric field in the depletion layer; that employment of a thin polymer coating on the anode side substantially mitigates the local field enhancement and improves the high-field reliability of the glass-polymer laminate. Cathode side polymer coating improves the laminate performance as well.