As a dielectric, mica provides capacitors with stable, highly accurate capacitance values. Mica capacitors exhibit low losses, which means they have a high quality factor (Q) and low dissipation factor (DF). For an explanation of these terms, read: The engineer’s capacitor glossary: All terms and acronyms defined.
Various mica capacitors use silver-inked mica sheets as a dielectric for better immunity to moisture and ionization. Mica capacitors are known for low tolerance (as low as 1%), low operating losses (dissipation factor of 0.001%), high-quality factor, and stability at high frequency.
Silver mica capacitors are usually rated for voltages between 100 and 1000 volts, although there are special high-voltage mica capacitors designed for RF transmitter use which are rated at up to 10 kV. Silver mica capacitors are used in applications which call for low capacitance values and high stability, while exhibiting low losses.
As the inventor of the mica capacitor, we are the world’s foremost authority and largest manufacturer of mica dielectric capacitors. Our RF mica capacitors feature superior high Q performance without the undesirable properties associated with ceramic and porcelain capacitors.
The medium of mica capacitors is mica sheet, and the electrodes are metal foil type and metal film type. Earlier mica capacitors consisted of metal foil or silver sprayed on the surface of the mica sheet to form electrodes, and then laminated them according to the required capacity and then diffused and pressed them into a bakelite shell.
The average temperature coefficient is around 50 ppm/°C. Mica capacitors have low resistive and inductive losses (high Q factor). Their characteristics are mostly frequency-independent, which allows for their use at high frequency. These superior characteristics come at a price: silver mica capacitors are bulky and expensive.