Introduction to High Voltage Ceramic Capacitors
There are two main types of ceramic materials for high-voltage ceramic capacitors: barium titanate based and strontium titanate based.
Barium titanate based ceramic materials have the advantages of high dielectric coefficient and good AC withstand voltage characteristics, but they also have disadvantages such as capacitance change rate increasing with medium temperature and insulation resistance decreasing.
The Curie temperature of strontium titanate crystal is -250 ℃, and it is a cubic perovskite structure at room temperature. It is a paraelectric and does not exhibit spontaneous polarization. Under high voltage, the dielectric coefficient of strontium titanate based ceramic materials changes little, and the tg δ The advantages of low capacitance change rate make it very advantageous as a medium for high-voltage capacitors.