Silver Mica

Silver mica capacitors are not as widely used these days as they used to be. However they can still be obtained and are used where stability of value is of the utmost importance and where low loss is required. In view of this one of their major uses is within the tuned elements of circuits like oscillators, or within filters.
Values are normally in the range between a few picofarads up to two or possibly three thousand picofarads.
For this type of capacitor the silver electrodes are plated directly on to the mica dielectric. Again several layers are used to achieve the required capacitance. Wires for the connections are added and then the whole assembly is encapsulated.