All capacitors that use ceramics as a material are called ceramic capacitors. Most people are called by patches and plug-ins, but this name is not very uniform. There are still many people who call them based on their shapes, such as chip ceramic capacitors, Round ceramic capacitors, tubular ceramic capacitors, etc. For semiconductor equipment, SMD ceramic capacitors are very important. Otherwise, semiconductor devices such as microprocessors, DSPs, microcomputers, FPGAs, etc., manufactured with new microfabrication technology will not work properly, so we must choose SMD ceramic capacitors. Be careful, let me talk about its characteristic parameters below.
Frequency characteristics: The electrical parameters change with the frequency of the electric field. The dielectric constant of capacitors operating at high frequencies will be lower than at low frequencies. Therefore, the higher the frequency, the greater the loss. In addition, when operating at high frequencies, the distribution parameters of the capacitor, such as the resistance of the pole piece, the resistance between the wire and the pole piece, etc., will affect the performance of the capacitor. All of this limits the frequency of use of capacitors.
Insulation resistance: indicates the magnitude of leakage current. Generally, the insulation resistance of a capacitor with a small capacity can reach hundreds of megaohms or thousands of megaohms. Electrolytic capacitors generally have low insulation resistance. Relatively speaking, the greater the insulation resistance, the smaller the leakage current.
Capacitance tolerance: Everyone can see this name. This is the tolerance range of the capacitance. Commonly used capacity errors are: J represents allowable deviation ±5%, K represents allowable deviation ±10%, and M represents allowable deviation ±20%.
Rated working voltage: It can work stably and reliably for a long time in the circuit, and withstand DC voltage, also called withstand voltage. For electronic devices with the same structure and capacity, the higher the withstand voltage, the larger the volume.
Loss: SMD ceramic capacitors consume energy due to heat generated per unit time under the action of electric field. This loss mainly comes from media loss and metal loss. It is generally expressed in terms of loss tangent.
With the advancement of materials, electrodes and manufacturing technology, the development of ceramic capacitors has made considerable progress and has been widely used. Ceramic capacitors have become one of the indispensable components of electronic products. Well, the content of this issue is here. If you have any questions, I look forward to your consultation!