Application of AlN in electronics industry

 As integrated circuit has become a strategic industry, many semiconductor materials have been researched and developed, and AlN is undoubtedly one of the most promising semiconductor materials. With the rapid development of microelectronics technology, electronic whole machine and electronic components are developing towards miniaturization, light, integration, and high reliability and high power output. More and more complex devices put forward higher requirements for heat dissipation of substrate and packaging materials.

AlN has the characteristics of high strength, high volume resistivity, high insulation and pressure resistance, thermal expansion coefficient, and good match with silicon. In the field of ceramic electronic substrate and packaging materials in recent years, its performance is far superior to alumina. The relatively low thermal conductivity of Al2O3 makes it difficult to meet the needs of future packaging. The industry needs a more advanced ceramic substrate with higher heat dissipation coefficient.

AlN is one of the few materials with good thermal conductivity and electrical insulation performance, and has the following advantages:

(1) High thermal conductivity of AlN, theoretical thermal conductivity at room temperature up to 320W/(m·K), is 8 to 10 times of alumina ceramics, the actual production of thermal conductivity can also be up to 200W/(m·K), is conducive to the chip heat emission, improve the performance of equipment;

(2) The expansion coefficient of AlN wire is small, with a theoretical value of 4.6×10-6/K, which is close to the thermal expansion coefficient of Si, a common semiconductor material, and its variation law is similar to that of Si.

(3) The energy gap width of AlN ceramics is 6.2eV, with good insulation, which does not need insulation treatment when applied to high-power packaging, simplifying the process;

(4) AlN is wurtzite type structure with strong covalent bond, so it has high hardness and high strength, and good mechanical properties. In addition, AlN has good chemical stability and high temperature resistance, can maintain stability in the air atmosphere temperature up to 1000℃, in the vacuum temperature up to 1400℃ stability is good, is conducive to sintering at high temperature, and corrosion resistance to meet the subsequent process requirements;

AlN has excellent performance in all aspects, especially in the thermal conductivity requirements of electronic packaging, aluminum nitride has great advantages. The only disadvantage is that the high cost of raw materials and processes makes AlN ceramics very expensive, which is the main problem that restricts the development of AlN substrates. However, with the continuous development of AlN preparation technology, its cost will be reduced, AlN ceramic substrate in 5G communication, LED packaging, power module, image sensing, automotive electronics, aerospace and other high-tech fields of large-scale application is expected.