Low voltage ceramic capacitor is also called dielectric capacitor, ceramic disc capacitor or ceramic capacitor. The low voltage ceramic capacitor we usually mean is the brown one, whose rated voltage is not higher than 1 KVDC, like the below picture shows.
There are many kinds of materials to make dielectric capacitor(ceramic disc capacitor),such as Z5U，Z5V，Y5V，Y5P，Y5U，Y5T，X7R，NPO，COG,N4700,etc.Many suppliers would like to mark the material type with Y5V or Y5U on the capacitor.Why it comes?
After studying, we learned that the temperature characteristics of different materials are very different. Please look at the beneath temperature curve.
We can have a glance on the above picture that the curves of material Z5V and Z5U are quite clear, like peaks. It means the temperature characteristics of these two kinds of material change very fast. It will affect the stability of the capacitor, while the other two materials Y5U and Y5P are much more stable. So the use of ceramic capacitor with Y5U or Y5V material is relatively common,besides,the materials are not very expensive.
The most stable material for making ceramic capacitor is X7R.The obvious feature is the excellent temperature characteristics, which is from -55C to +125C, while that of any other materials is -40C to +85C.
There are some customers require the suppliers to make ceramic capacitor with material like NPO or COG. There two materials are relative good materials when used for high-precision products.