Views: 2 Author: Site Editor Publish Time: 2018-11-15 Origin: Site
In general, ceramic capacitors and high-frequency capacitors are two capacitors that are very similar. In fact, high-frequency capacitors and ceramic capacitors are different. High frequency capacitors are one type of ceramic capacitors.
The ceramic capacitor is extruded from a high dielectric constant capacitor ceramic (barium titanate titanate) into a circular tube, a disk or a disk as a medium, and is plated with silver on the ceramic as an electrode by a fire infiltration method. It is divided into two types: high frequency porcelain and low frequency porcelain.
Ceramic capacitors have small positive temperature coefficient capacitors for use in high-stability oscillator circuits as loop capacitors and pad capacitors.
Low-frequency ceramic capacitors are limited to bypass or DC-blocking in circuits with lower operating frequencies, or where stability and loss are not critical (including high frequencies). Such capacitors are not suitable for use in pulse circuits because they are susceptible to breakdown by pulse voltages.
The high-frequency ceramic capacitor is formed by spraying a special mixture suitable for spraying into a thin film, and the medium is sintered by a silver layer electrode to form a monolith structure. High frequency ceramic capacitors are suitable for high frequency circuit mica capacitors. In terms of structure, it can be divided into a foil type and a silver type. The silver electrode is directly deposited on the mica plate by vacuum evaporation or infiltration, and the temperature coefficient is greatly reduced due to the elimination of the air gap, and the capacitance stability is also higher than that of the foil type.
The ceramic capacitor is mainly for high frequency, and the high voltage ceramic capacitor depends on the occasion of use. The typical function can eliminate high frequency interference.
Advantages of ceramic capacitors:
Capacity loss is highly stable with temperature frequency.
The special series structure is suitable for high voltage and long-term operational reliability.
High current climb rate and suitable for high current loop non-inductive structures.
The high frequency capacitor has good frequency characteristics, high Q value and small temperature coefficient; it cannot be made into a large capacity; it is widely used in high frequency electrical appliances and can be used as a standard capacitor glass glaze capacitor. Performance is comparable to mica capacitors, can withstand a variety of climatic conditions, generally can work at 200 ° C or higher, rated working voltage up to 500V, loss tg δ 0.0005 ~ 0.008.
