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

High resistivity, high thermal conductivity, and low dielectric constant are the most basic requirements for integrated circuits for package substrates. The package substrate should also have good thermal matching, easy molding, high surface flatness, easy metallization, easy processing, low cost and certain mechanical properties. Most ceramics are extremely ionic or covalently bonded materials, have excellent overall properties, are commonly used in electronic packaging, have high insulation properties and excellent high frequency characteristics, while linear expansion coefficient and electrons. The components are very similar, the chemical properties are very stable and the thermal conductivity is high. 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, it is higher. The production cost and the shortcomings of the highly toxic have limited its application promotion. Therefore, considering the factors of performance, cost and environmental protection, 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 technology and optoelectronic technology, so the research on various new electronic thin film materials has become a hot spot of many researchers. AlN was discovered in the 1860s as an electronic film material and has a wide range of applications. In recent years, wide-bandgap semiconductor materials and electronic devices represented by Group III nitrides have developed rapidly, and are called the third generation after the first generation semiconductor represented by Si and the second generation semiconductor represented by GaAs. semiconductor. As a typical IIIA nitride, A1N has received more and more attention from researchers at home and abroad. At present, countries are competing to invest a lot of manpower and material resources in the research of AlN film. Because of its excellent performance, A1N has wide bandgap, strong polarization, and a forbidden band width of 6.2eV, making it suitable for mechanical, microelectronic, optical, and electronic components, surface acoustic wave device (SAW) manufacturing, high-frequency broadband communication. And power semiconductor devices and other fields have broad application prospects. AlN's excellent performance determines its various applications. As a piezoelectric film, it has been widely used. As a package, dielectric isolation and insulating material for electronic devices and integrated circuits, it has important application prospects; as a blue light and ultraviolet light-emitting material. It is also a current research hotspot.

At present, in order to improve the vulnerability of ceramic materials, many researches have been carried out. The method of forming the multiphase ceramic by adding the second phase and the third phase particles also becomes a means for improving the toughness of the ceramic material. Compared with the method of adding whiskers and fibers, the method has the characteristics of low cost and easy preparation. Silicon carbide materials have been widely used in mechanical, chemical, energy and military applications due to their high hardness, high temperature strength, wear resistance, corrosion resistance and low density. However, due to its low room temperature strength and insufficient toughness, its application is limited. In order to improve the strength and toughness of SiC ceramic materials, some achievements have been made by using the method of adding metal phase dispersion strengthening using the second phase particles. For example, SiC/TiC, Sic/Al203, and SiC/TiB2.

Aluminum nitride (AlN) has high thermal conductivity (theoretical thermal conductivity is 320W/(m•K), and the actual value is up to 260W/(m•K), which is 10 to 15 times that of alumina ceramics). Low relative dielectric constant (approx. 8.8), reliable electrical insulation (resistivity > 1016Q•m-1), high temperature resistance, corrosion resistance, non-toxicity, good mechanical properties and thermal expansion coefficient matched with silicon ( A series of excellent properties such as 20 ° C ~ 500 ° C, 4.6 × 10-6K -1), more and more widely used in many high-tech fields, many of which require AlN as shaped and micro-pieces, but traditional molding And the isostatic pressing process can not produce ceramic parts with complex shapes, and the inherent toughness of AlN ceramic materials is low, brittle and difficult to process, making it difficult to prepare complex-shaped AlN ceramics by conventional machining methods. Parts. 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 important part.