AlN formula: A1N (b)AlN3 (c)AlN3 (d)AlN4
The refractory compound ceramic material aluminum nitride has hexagonal wurtzite structure with a tetrahedral coordination of nitrogen. It has a high thermal conductivity, low dielectric constant and dielectric loss.
This material can be synthesized by carbothermal reduction of aluminium oxide in the presence of gaseous nitrogen or ammonia or by direct nitridation with a sintering aid such as Y2O3. It is stable to very high temperatures, above 700 degC in air.
Typical applications include furnace tools and components, molten metal crucibles and liners, refractory coatings, RF/Microwave components and for IC packages and substrates. Epitaxial grown AlN is used for surface acoustic wave sensors on silicon wafers.
AlN is also an insulator, which makes it suitable for heat sinks in power and electronics devices where heat dissipation is important. Moreover, it has excellent electrical insulation properties and can resist corrosion.
In addition, it is a good choice for advanced fuel cells and battery applications where hydrogen storage is a primary concern. Hydrogen can be easily generated from renewable energy sources such as water and fossil fuels.
The high thermal conductivity of AlN enables it to be used as a heat dissipation substrate for electronics devices such as power modules (MOSFET, IGBT) and LED packages for cooling and protecting circuits. It has similar coefficient of thermal expansion to that of silicon.
It is a very good choice for heat dissipation substrate for micro-electromechanical systems (MEMS). It has very high piezoelectricity and sound acoustic wave velocity, as well as excellent electrical resistivity.
