Aluminum nitride (AlN) is a new ceramic material with excellent comprehensive performance, with excellent thermal conductivity, reliable electrical insulation, low dielectric constant and dielectric loss, non-toxic and silicon matching thermal expansion coefficient and a series of excellent characteristics, is considered to be a new generation of high-concentration semiconductor substrate and electronic device packaging ideal material. It has been widely valued by researchers at home and abroad. In theory, the thermal conductivity of AlN is 320W/(m), and the thermal conductivity of polycrystalline aluminum nitride actually prepared in industry can also reach 100~250W/(m), which is 5 ~10 times the thermal conductivity of traditional substrate material alumina, and close to the thermal conductivity of beryllium oxide, but because beryllium oxide is highly toxic, it is gradually stopped in industrial production. Compared with other ceramic materials, aluminum nitride ceramics have excellent comprehensive properties and are very suitable for semiconductor substrates and structural packaging materials, and have great application potential in the electronics industry.

High resistivity, high thermal conductivity and low dielectric constant are the most basic requirements of integrated circuits for packaging substrates. The packaging substrate should also have good thermal matching, easy forming, high surface flatness, easy metallization, easy processing, low cost and certain mechanical properties with silicon wafers. Most ceramics are ionic bond or covalent bond strong materials, with excellent comprehensive performance, is commonly used in electronic packaging substrate materials, with high insulation properties and excellent high frequency characteristics, while the coefficient of linear expansion and electronic components are very similar, chemical properties are very stable and high thermal conductivity. For a long time, the substrate materials of most high-power hybrid integrated circuits have been using A1203 and BeO ceramics, but the thermal conductivity of A1203 substrate is low, and the thermal expansion coefficient is not well matched with Si. Although BeO has excellent comprehensive performance, its high production cost and high toxicity limit its application and popularization. Therefore, from the performance, cost and environmental protection factors, the two can not fully meet the needs of the development of modern electronic power devices.

Electronic thin film materials are the basis of microelectronics and optoelectronics technology, so the research of various new electronic thin film materials has become the focus of many researchers. AlN was discovered in the 1860s as an electronic thin film material and has a wide range of applications. In recent years, wide-band gap semiconductor materials and electronic devices represented by ⅢA nitrides have developed rapidly, and are called the third generation semiconductor after the first generation semiconductor represented by Si and the second generation semiconductor represented by GaAs. As a typical ⅢA nitride, AIN has been paid more and more attention by researchers at home and abroad. At present, countries are competing to invest a lot of manpower and material resources to research AlN thin films. Because AIN has many excellent properties, bandgap width, strong polarization, and bandgap width of 6.2eV, it has broad application prospects in mechanical, microelectronics, optics, and electronic components, surface acoustic wave device (SAW) manufacturing, high frequency broadband communication and power semiconductor devices. AlN has been widely used as a piezoelectric film because of its excellent properties. As a packaging, dielectric isolation and insulation material for electronic devices and integrated circuits, it has important application prospects. As a blu-ray and UV-emitting material, it is also a research hotspot at present.

At present, in order to improve the fragility of ceramic materials, many researches have been carried out. The addition of second and third phase particles to form composite ceramics is also a means to improve the toughness of ceramic materials. Compared with the addition of whiskers and fibers, this method has the advantages of low cost and easy preparation. Silicon carbide material by its high hardness, high temperature strength, wear resistance, corrosion resistance, relatively small density and other excellent properties, in machinery, chemical industry, energy and military industry has been widely used. However, its application is limited due to its low strength at room temperature and lack of toughness. In order to improve the strength and toughness of silicon carbide ceramic materials, some achievements have been made by using the second phase particle addition method for reference to the metal dispersion strengthening theory. For example, SiC/TiC, Sic/A1203, and SiC/TlB.

Aluminum nitride (AlN) has a high thermal conductivity (theoretical thermal conductivity is 320W/(m•K), and the actual value can reach 260W/(m•K). 10 times to 15 times of alumina ceramics), low relative dielectric constant (about 8.8), reliable electrical insulation (resistivity >1016Q•m-1), high temperature resistance, corrosion resistance, non-toxic, good mechanical properties and matching with silicon thermal expansion coefficient (20℃~500℃, 4.6× 10-6k-1) and a series of excellent properties. More and more widely used in many high-tech fields, many of which require AlN to be shaped parts and miniature parts, but the traditional molding and isostatic pressing process can not prepare complex shape ceramic parts, plus AlN ceramic materials inherent low toughness, brittleness, difficult to process the shortcomings. It is difficult to prepare complex shape AlN ceramic parts by traditional machining methods. In order to give full play to the performance advantages of AlN, broaden its application range, and solve the complex shape forming technology problem of AlN ceramics is a very key link.