Alumina is generally available in two concentrations: 99.5% and 96%. This ceramic is the workhorse of the microwave integrated circuit (MIC) business. 96% alumina is primarily used in high-temperature co-fired circuits, while 99.5% alumina is primarily used in thin film networks.
The data came from CoorsTek. The other 4% of the material is probably made up of some type of glass to lower the melting temperature.
Author : Unknown Editor