What material is aluminum nitride ceramic?

Aluminum Nitride (AIN) is famous for its high thermal conductivity and excellent electrical insulation performance. It is a common ceramic material used in various electrical equipment. In addition to the coefficient of thermal expansion and electrical insulation, aluminum nitride ceramics can resist the corrosion of most molten metals, such as copper, lithium and aluminum.

Aluminum nitride (AlN) is a kind of non oxide ceramic material basically composed of aluminum and nitrogen (Al-65.81%, N-34.19), with the chemical formula of AlN. It is a solid nitride of aluminum, with high thermal conductivity up to 321 W, and can also be used as an excellent electrical insulator. The band gap of AlN wurtzite phase is about 6 eV at room temperature. Because of these properties, this ceramic has been proven to be useful in many applications, such as optoelectronics at deep ultraviolet frequencies.

Aluminum nitride is composed of F Briegleb and A Geuther was first synthesized in 1862. The ceramic materials mainly exist in hexagonal wurtzite crystal structure. However, it can also be used for metastable cubic sphalerite phase, mainly for film synthesis. It is predicted that the cubic phase of AlN can actually exhibit superconductivity under high pressure.

The polycrystalline structure of aluminum nitride (AlN) has high thermal conductivity, so it has electrical insulation properties. In terms of density, aluminum nitride is a covalent bond compound, and the theoretical density is 3.26g/cm3.

Properties of aluminum nitride ceramics

Aluminum nitride has many characteristics that make it suitable for various industrial applications:

High thermal conductivity (above 170W/mK). This is close to the value of BeO and SiC, more than five times that of alumina (Al2O3).

Its thermal expansion coefficient is 4.5 * 10-6 ℃, which is the same as silicon (3.5-4 * 10-6 ℃).

It has good light transmission characteristics.

It is not toxic.

Good conductivity. The electrical properties of aluminum nitride include its dielectric constant, dielectric loss, volume resistivity and dielectric strength - all of which make it an excellent insulating material.

Good mechanical properties: The mechanical properties of aluminum are also the reason why it is widely used in industrial processes. It has higher bending strength than alumina (Al2O3) and beryllium oxide (BeO) ceramics.

Why aluminum nitride ceramics are widely used

Aluminum nitride ceramics have been used in many fields due to their good properties, including high thermal conductivity, low dielectric constant and dielectric loss, high insulation strength and significant resistance to plasma erosion. Some common applications of this material are:

Chip cooling and support;

Application of aluminum nitride ceramic substrate (ceramic tray) in semiconductor devices;

Etching shielding of aluminum nitride;

Aluminum nitride evaporation boat for OLED;

Another important use case for aluminum nitride ceramics is the manufacture of plastics and resins. These materials usually have low thermal conductivity (less than 0.3W/mk). By adding aluminum nitride powder to plastics and resins, they produce thermal conductive potting compounds and thermal conductive pads with high thermal conductivity, usually higher than 10W/mk. They are also used for packaging various electronic components.

More and more researchers are studying the use of gallium nitride based semiconductors to produce light-emitting diodes that work in the ultraviolet region. These studies indicate that it is possible to achieve wavelengths as short as 250 nm using AlGaN alloys.

Application of aluminum nitride ceramics

Radiators and radiators;

Steel and semiconductor manufacturing;

Electrical insulator;

Silicon wafer processing and processing;

As a crucible for growing GaAs crystals;

Used as substrate and insulator of microelectronic devices;

Electronic packaging substrate;

Chip carrier of sensors and detectors;

Laser thermal management components;

Used as a dielectric layer in an optical storage medium;

Molten metal clamp;

Microwave device packaging;

photoelectricity.