MICA CAPACITORS

Mica is popularly known as Isin glass. Important characteristics of Mica:

i) Its ability to operate at very high temperature (upto 500 ^oC).

ii) The material is almost totally inert and will not change with age, either chemically or physically.

iii) Mica is usable as a dielectric in its naturally state.

iv) It can be readily split into very thin sheets.

Mica capacitors are made by a method of depositing a thin layer of silver on each side of sheet of Mica was developed. This is done by a type of silver screen process. The silver is then fired in a furnace.

The principal advantage of Mica capacitor is its excellent degree of stability over a wide range of operating temperatures.

Mica capacitors are also among the best types to use where radio frequencies are involved.

Disadvantages of Mica capacitors:

i) They are relatively bulky when compared to other capacitors on a pure capacitance vs volume basis.

ii) The flat plates and method of construction lead to resonant frequency problems in some circuits.