High Temperature Performance of Coiled Glass Capacitors

Alkali-free flat panel display glass is produced in large quantity and has excellent electrical insulating properties at high temperature. Aluminum borosilicate glass with alkaline-earth modifier has low sodium content and low dielectric loss (tan δ <0.1 at 250°C), high dielectric breakdown strength (109 V/m) and excellent high temperature stability. In addition, roll-to-roll processing of thin glass sheet has been demonstrated and glass capacitors that are configured in a coil. Excellent high power capability of these glasses was confirmed by analytical, finite element, and finite difference modeling. The modeling work indicates that a combination of hybrid electrode design and effective heat loss at the interface can further extend power capability of glass capacitors. Alkali-free glass is an ideal candidate material for high temperature capacitors.