Investigations Into 25- and 30- $\mu \text{m}$ -Thick Glass Capacitors at 23 °C and 235 °C and Area Dependence of Dielectric Strength of Alkali-Free Schott Inc. AF 32 ECO Glass

Parallel-plate capacitors constructed with 25-and 30-μm-thick alkali-free glass sheets are demonstrated in pulsed RC discharge circuit. Capacitance values ranged from ~25 to 54 nF. Capacitors were charged and discharged with an electrically triggered switch into resistive loads and were tested at 23 °C in oil up to 3.2 kV and up to 235 °C in air with a charge voltage of 350 V. Peak currents greater than 160 A were measured for multiple capacitor charge and discharge cycles for the capacitor submerged in oil. To our knowledge, this is the first demonstration of an ultrathin glass capacitor with multikilovolt charge voltage implement in a pulsed power electrical circuit. In addition, the dielectric strength of 25-μm-thick alkali-free Schott Inc. AF 32 ECO glass is investigated in Shell Diala oil at room temperature as a function of electrode area spanning a factor of 600. The results show that as electrode area increases dielectric strength significantly decreases. Implications for the decrease in dielectric strength at large dielectric areas are discussed in regard to manufacturing ultrathin glass capacitors. Dielectric strengths measured for AF 32 ECO glass are in agreement with similar compositions of alkali-free glass.