Alumina ceramics are ceramic materials based on alumina (Al2O3) for thick film integrated circuits. Alumina ceramics have good electrical conductivity, mechanical strength and high temperature resistance. It should be noted that ultrasonic cleaning is needed. Alumina ceramics is a kind of universal ceramics. Because of its superior performance, it has been widely used in modern society to meet the needs of daily use and special performance.
Alumina ceramics can be divided into two types: high purity type and common type.
The content of Al 2 O 3 in high purity alumina ceramics is over 99.9%. Because the sintering temperature is as high as 1650-1990 C and the transmission wavelength is from 1 to 6 microns, the platinum crucible is usually replaced by molten glass. Resistance and alkali corrosion resistance are used as sodium lamps; it can be used as integrated circuit substrates and high frequency insulation materials in the electronic industry.
Ordinary alumina ceramics can be divided into 99 kinds, 95 kinds, 90 kinds and 85 kinds according to the content of Al 2 O 3. Sometimes the content of Al2O3 is 80% or 75%, which is also classified as ordinary alumina ceramic series. Among them, 99 Kinds of alumina ceramics are used to make high temperature crucibles, refractory furnace tubes and special wear-resistant materials, such as ceramic bearings, ceramic seals and water valve plates; 95 kinds of alumina ceramics are mainly used as corrosion-resistant and wear-resistant parts; in addition, because of the addition of talcum powder, electrical properties and mechanical strength are improved, and metal seals such as molybdenum, niobium and tantalum can be used, and Some of them are used as electric vacuum devices.
Properties of alumina ceramics: high hardness, high strength, abrasion resistance, corrosion resistance, high temperature (1600 degrees), good thermal diffusivity, good insulation, low cost and so on.