Solid tantalum capacitors are 1956 It was first successfully developed by the American Beller Laboratory in 2008. It has excellent performance and is the smallest product among all capacitors that can achieve larger capacitance. Tantalum capacitors are available in a variety of shapes and are easily fabricated into small and chip components suitable for surface mounting. It meets the needs of the current electronic technology automation and miniaturization development. Although tantalum raw materials are scarce and tantalum capacitors are expensive, tantalum electrolytic capacitors have been rapidly developed due to the large use of high specific capacity tantalum powder (30KuF.g-100KuF.V/g) and the improvement and perfection of the capacitor manufacturing process. development, the scope of use is becoming wider and wider. Tantalum capacitors are not only widely used in military communications, aerospace and other fields, but also widely used in industrial control, video equipment, communication instruments and other products.
Currently produced tantalum electrolytic capacitors mainly include sintered solid, foil wound solid, and sintered liquid. Among them, sintered solid accounts for more than 95% of the current total production, and is encapsulated with non-metallic sealed resin. formula as the main body. Miniaturization, chip type and SMT technology are in the ascendant, and chip sintered tantalum capacitors have gradually become the mainstream.
Solid tantalum capacitors have excellent electrical properties, wide operating temperature range, various forms, and excellent volume efficiency. They have unique characteristics:
The working medium of tantalum electrolytic capacitors is a very thin layer of tantalum pentoxide film formed on the surface of tantalum metal.
This layer of oxide film dielectric is completely combined with one end of the capacitor and cannot exist alone. Therefore, the capacitance per unit volume is particularly large. That is, the specific capacity is very high, so it is particularly suitable for miniaturization.
●During the working process of tantalum electrolytic capacitors, it has the performance of automatically repairing or isolating the defects in the oxide film, so that the oxide film medium can be reinforced at any time and its proper insulating ability can be restored without suffering continuous cumulative damage. This unique self-healing property ensures its long life and reliability advantages.
●Tantalum electrolytic capacitors have a very high working electric field strength, which is larger than any type of capacitor, so as to ensure its miniaturization.
●Tantalum electrolytic capacitors can easily obtain larger capacitance, and there are few competitors in power supply filtering, AC bypass and other applications.
● It has unidirectional conductivity, that is to say, it has "polarity". During application, the current should be connected in the positive and negative directions of the power supply. The anode (positive pole) of the capacitor is connected to the "+" pole of the power supply, and the cathode (negative pole) is connected to the "+" pole of the power supply. If the connection is wrong, not only the capacitor will not work, but also the leakage current is very large, the core will heat up in a short time, and the oxide film will be damaged immediately.
●The working voltage has a certain upper limit value, but this shortcoming is not important for matching transistor or integrated circuit power supply. Electrolytic capacitors are generally considered to be electronic components with excellent performance and long service life, and their failure rate can reach seven levels when normal. However, it always conforms to the general law of failure of electronic components, that is, the bathtub-shaped failure curve, and the early failure can be eliminated in the aging process. So there is only the possibility of random failures. And this kind of inefficiency is the problem of manufacturing process control, and it is often caused by improper use or overload of the product. Generally speaking, there are about three modes, namely current mode, voltage mode and heating mode.
● Tantalum electrolytic capacitors have the properties of storing electricity, charging and discharging, etc. They are mainly used in filtering, energy storage and conversion, mark bypass, coupling and decoupling, and time constant components. Pay attention to its performance characteristics in application, and correct use will help to give full play to its functions, such as considering the working environment of the product and its heating temperature, and taking measures such as derating, if it is used improperly, it will affect the working life of the product.
