Porcelain dielectric capacitors are also called ceramic capacitors. They use ceramic as a medium, coated with a metal film (usually silver) and sintered at high temperature to form electrodes, and then solder lead wires on the electrodes, and coat them with protective enamel or epoxy resin. And encapsulated by independent resin, it becomes a ceramic capacitor.
The ceramic material used as the dielectric of the capacitor is made from various raw materials and sintered at high temperature according to different recipes. The formulation of pottery materials is different, and its electrical properties are also different. Using this point, a variety of capacitors with different dielectric constants and different temperature coefficients can be manufactured to meet different usage requirements.
There are three types of ceramic dielectric materials commonly used in ceramic capacitors:
Type I capacitor ceramics: its dielectric constant is generally less than 100, and its electrical performance is stable, basically not changing with temperature, voltage, and time. It is an ultra-stable, low-loss capacitor dielectric material, often used for stability and reliability. High frequency, ultra high frequency, and very high frequency occasions are required.
Type Ⅱ capacitor ceramic: Its dielectric constant is generally greater than 1000, and its electrical performance is relatively stable. It is suitable for direct isolation, coupling, bypass and clean, wave circuits and medium and low-frequency applications that require high reliability. In-type capacitor Tao Meng: It has a high dielectric constant and is widely used in occasions where the capacity stability and loss are not high.
Capacitors with ferrite-based ceramic materials as the dielectric are called monolithic ceramic capacitors, which are made by stacking and sintering multilayer ceramic films. Because each piece of ceramic film is very thin, it has the characteristics of large capacity and small volume.