Solid state capacitor is called solid state aluminium electrolytic capacitor. The biggest difference between liquid aluminium capacitor and ordinary capacitor is that different dielectric materials are used. Liquid aluminium capacitor dielectric material is electrolyte, while solid capacitor dielectric material is conductive polymer.
For friends who often go to Internet cafes or use computers for a long time, they must have had or heard something about the instability of computers or even the bursting of capacitors caused by card capacitors. That is because one side of the panel card is used for a long time, overheating leads to the expansion of electrolyte heating, resulting in the loss of capacitance and even the expansion burst caused by the boiling point. On the other hand, if the board is not electrified for a long time, the electrolyte will easily react with alumina, resulting in explosion when starting or electrifying. But if solid-state capacitors are used, there will be no such dangers and dangers at all! uuuuuuuuuu
_Because solid-state capacitors use conductive polymer products as dielectric materials, the material will not react with alumina, and will not explode after electrification; at the same time, it is a solid-state product, naturally there is no explosion caused by thermal expansion.
Solid-state capacitors have the advantages of environmental protection, low impedance, high and low temperature stability, high ripple resistance and high reliability. They are the highest-ranking products in electrolytic capacitors. Because solid-state capacitor is much better than liquid aluminium capacitor, its temperature resistance is 260 degrees, and its conductivity, frequency characteristics and life are good. It is suitable for low voltage and high current applications. It is mainly used in digital products such as thin DVD, projector and industrial computer. In recent years, it has also been widely used in computer card products.
_In fact, the patch capacitor is essentially the same as the electrolytic capacitor described above. The difference between them is only in the packaging or welding process.
_Whether plug-in or patch mounting process, the capacitor itself is upright on PCB, the fundamental difference is SMT patch process mounting capacitor, with a black rubber base. The benefits of SMT lie mainly in the production. SMT has high automation and precision, and is not as vulnerable to damage as plug-in type in transportation. Because of the low cost of machinery and the high cost of labor in European and American factories, most of them prefer SMT patch manufacturing. Domestic factories have cheaper labor, so manufacturers prefer to use plug-in installation.
The core of the aluminium electrolytic capacitor is made of four layers of overlapping winding: anode aluminium foil, electrolytic paper, cathode aluminium foil and electrolytic paper. After the core contains electrolyte, it is sealed with aluminium shell and rubber cover to form an electrolytic capacitor. Compared with other types of capacitors, the structure of aluminium electrolytic capacitors shows the following obvious characteristics:
(1) The working medium of aluminium electrolytic capacitor is a thin layer of aluminium trioxide (Al2O3) formed on the surface of aluminium foil by anodic oxidation. The oxide dielectric layer and the anode of capacitor are integrated into a complete system. They are interdependent and cannot be independent of each other. The electrodes and dielectrics of capacitors are independent of each other.
(2) The anode of aluminium electrolytic capacitor is aluminium foil with Al2O3 dielectric layer on its surface. The cathode is not the negative foil we used to think of, but the electrolyte of the capacitor.
(3) Negative foil plays an electrical role in electrolytic capacitors, because the electrolyte as cathode of electrolytic capacitors can not be directly connected with external circuit, it must form an electrical path through another metal electrode and other parts of the circuit.
(4) The anode and cathode aluminum foils of aluminium electrolytic capacitors are usually corroded aluminium foils. The actual surface area is much larger than the apparent surface area, which is also one of the reasons why aluminium electrolytic capacitors usually have large capacitance. Due to the use of aluminum foil with many Micro-etching holes, liquid electrolyte is usually needed to make more effective use of its actual electrode area.