Aluminum Nitride (AlN)

What are aluminum nitride ceramics?

Aluminum nitride ceramic is one of the advanced ceramic materials and is widely used in the electronics industry because of its excellent thermal conductivity and electrical insulation properties.

Aluminum nitride crystal is a covalently bonded compound with [AIN4] tetrahedron as the structural unit. It has a wurtzite structure and belongs to the hexagonal crystal system. As a high-temperature-resistant material, its single-crystal thermal conductivity is almost five times that of alumina, and it has good thermal shock resistance and can be used in an environment of 2200°C.

Aluminum nitride is resistant to attack by molten metal and stable to acids. When its surface is exposed to moist air, it will react to form an extremely thin oxide film. Taking advantage of this characteristic, it can be used as a crucible and firing mold material for the smelting of aluminum, copper, silver, lead and other metals. AIN ceramics have better metallization properties and can replace toxic beryllium oxide ceramics and are widely used in the electronics industry.

Aluminum Nitride

The chemical formula of aluminum nitride
The chemical formula of aluminum nitride is AlN, and its chemical composition is AI 65.81% and N 34.19%. Its powder is white or off-white, the single crystal is colorless and transparent, and its sublimation decomposition temperature under normal pressure is 2450°C.

Thermal conductivity
The thermal conductivity of aluminum nitride ceramics is between 170~210 W / (m.k), and the thermal conductivity of single crystal can be as high as more than 275 W / (m.k), which is 5 times that of alumina.

Advantages of aluminum nitride ceramic substrates
It has high thermal conductivity, low expansion coefficient, high strength, high temperature resistance, chemical corrosion resistance, high resistivity and low dielectric loss. It is an ideal large-scale integrated circuit heat dissipation substrate and packaging material.

Characteristics of aluminum nitride
The thermal conductivity is high (>170W/m·K), close to BeO and SiC, and more than 5 times that of Al2O3; the thermal expansion coefficient (4.5×10-6℃) is similar to Si (3.5~4×10-6℃) and GaAs ( 6×10-6℃); excellent in various electrical properties (dielectric constant, dielectric loss, volume resistivity, dielectric strength); good mechanical properties, higher flexural strength than Al2O3 and BeO ceramics, and can be sintered at normal pressure; Can be produced using tape casting process. It is a promising high-power integrated circuit substrate and packaging material.

Application
Heat sinks and heat sinks; electrical insulators for lasers; chucks, clamping rings for semiconductor processing equipment; electrical insulators; silicon wafer processing; substrates and insulators for microelectronic and optoelectronic devices; electronic packaging substrates; chip carriers for sensors and detectors ; Molten metal fixture.