Chip capacitor short circuit and leakage cause

Chip capacitor short-circuit and leakage occur in different circuits. For example, after the coupling circuit is short-circuited, the DC current will flow directly to the next stage. This current is not the noise, and the filter capacitor may blow the fuse when it breaks down. .

This has to start with the structure of the capacitor. The simplest capacitor is made up of plates at both ends and an insulating dielectric (including air) in between. After energization, the plates are charged, forming a voltage (potential difference), but due to the intermediate insulating material, the entire capacitor is not electrically conductive. However, such a situation is under the premise that the threshold voltage (breakdown voltage) of the capacitor is not exceeded. We know that any substance is relatively insulated. When the voltage across the material increases to a certain extent, the substance can conduct electricity. We call this voltage the breakdown voltage. Capacitance is no exception. After the capacitor is broken down, it is not an insulator.

However, in the middle school stage, voltages such as axial capacitance are not seen in the circuit, so they all work below the breakdown voltage and can be viewed as an insulator. However, the axial capacitance is in the AC circuit because the direction of the current varies over time as a function of time. The process of charging and discharging the capacitor is time-consuming. At this time, a varying electric field is formed between the plates, and this electric field is also a function of time. In fact, the current is passed between the capacitors in the form of a field.

A device having a charge storage capability by separating two parallel conductive electrode plates with an insulating material is called a capacitor (capacitor or condenser). The electrode plate is called the electrode of the capacitor, and the insulating material is called a dielectric or a medium for short.

Capacitance is used to indicate the ability (or capacity) of a capacitor to store a charge. Various capacitors have different capacitances due to factors such as the size of the conductor, the distance between the plates, and the type of the medium. However, the amount of charge Q that can be stored is proportional to its potential V, ie Q=CV. The proportionality constant C in the equation is the capacitance of the capacitor, referred to as the capacitor. The unit of C=Q/V capacitance is “Liueng/Volt”. In order to commemorate the great contribution of scientist Faraday (Michael Faraday l791～1867, English) to electric power, the capacitance of 1 coulomb/volt is called 1 farad. Referred to as the law, the unit symbol is F or f. In practice, the unit of Farah is often too large. For example, if a sphere requires a capacitance of 1 Farad, the axial capacitance must have a radius of 9*10e9 meters! Therefore, it is often micro-method (μF) or pico method (μμF or pF). The axial capacitance is used to indicate the magnitude of the capacitance value.