Introduction of Mica Capacitor

Mica capacitor is a kind of capacitor, and its shape is mostly square. Mica capacitor uses natural mica as the medium between capacitors, so its withstand voltage and high performance are quite good. The electrode plate is made of metal foil or sprayed with a silver layer on the mica sheet. The electrode plate and the mica are laminated one by one, and then die-cast in bakelite powder or sealed in epoxy resin. It is characterized by low dielectric loss, large insulation resistance, and low temperature coefficient, making it suitable for high-frequency circuits.

 Mica capacitors mainly use natural muscovite as the medium, so the capacitance is very stable, the high frequency loss is small, the error can reach ±1%, but the general error is ±5%, ±10%, ±20%. The withstand voltage can range from hundreds of volts to several thousand volts, or even tens of thousands of volts, and the capacity ranges from a few picofarads to tens of thousands of picofarads. Moisture resistance is generally 80% to 98% relative humidity, working at a temperature of minus 60°C to a temperature of plus 70°C, and will not change the capacity due to humidity, high and low temperatures, so the capacity is relatively stable.For example, mica capacitors used in radios have two structures, one is to use aluminum foil (or tin foil) and mica sheets stacked one after another. The other is silver on mica flakes, layer by layer, and lead clips on both ends and pressed into bakelite powder. The capacity of the silver foil is more stable than that of the aluminum foil, and the temperature coefficient is smaller, but the appearance is the same.


Mica capacitors are used in radio receiving and sending equipment, precision electronic instruments, modern communication instruments and equipment, radios, power amplifiers, televisions, etc.


According to the structure, it is divided into three categories: fixed capacitors, variable capacitors and trimmer capacitors.

Classified by electrolyte: organic dielectric capacitors, inorganic dielectric capacitors, electrolytic capacitors and air dielectric capacitors.

According to the purpose, there are: high frequency bypass, low frequency bypass, filtering, tuning, high frequency coupling, low frequency coupling, small capacitors.

According to the different manufacturing materials, it can be divided into: ceramic capacitors, polyester capacitors, electrolytic capacitors, tantalum capacitors, and advanced polypropylene capacitors.

High frequency bypass: ceramic capacitors, mica capacitors, glass film capacitors, polyester capacitors, glass glaze capacitors.

Low-frequency bypass: paper capacitors, ceramic capacitors, aluminum electrolytic capacitors, polyester capacitors.

Filtering: aluminum electrolytic capacitors, paper capacitors, composite paper capacitors, liquid tantalum capacitors.

Post time: Nov-30-2020
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