Characteristics of ceramic substrate materials for electronic packaging


Ceramic substrate is a commonly used electronic packaging substrate material. Compared with plastic packaging material and metal substrate, its advantages lie in the following aspects:

Ceramic substrate is a commonly used electronic packaging substrate material. Compared with plastic packaging material and metal substrate, its advantages lie in the following aspects:
1) Good insulation performance and high reliability. High resistivity is the basic requirement of electronic components for substrates. Generally speaking, the greater the substrate resistance, the higher the packaging reliability. Ceramic materials are generally covalent bond compounds with good insulation performance.
2) The dielectric coefficient is small and the high frequency characteristic is good. The low dielectric constant and dielectric loss of ceramic materials can reduce the signal delay time and improve the transmission speed.
3) The coefficient of thermal expansion is small, and the thermal mismatch rate is low. Covalent bond compounds generally have high melting point characteristics. The higher the melting point, the smaller the thermal expansion coefficient, so the thermal expansion coefficient of ceramic materials is generally small.
4) High thermal conductivity. According to the traditional heat transfer theory, the theoretical thermal conductivity of ceramic materials such as BeO, SiC and AlN of cubic system is no less than that of metal.
Therefore, ceramic substrate materials are widely used in the packaging of products with high reliability, high frequency, high temperature resistance and strong air tightness in aviation, aerospace and military engineering. The packaging of ceramic substrate materials is generally multilayer ceramic substrate packaging. This technology originated from the tape casting process invented by PARK in 1961, and was later widely used in hybrid integrated circuit (HIC) and multi chip module (MCM) ceramic packaging.
Since the 1960s, the United States, Japan and others have successively introduced laminated multilayer ceramic substrate packaging materials and processes. Ceramic substrates have become one of several high-tech ceramics widely used in the world. At present, the mature ceramic substrate material is Al2O3 substrate, which has good electrical and mechanical properties. In addition to Al2O3, there are also A1N, BeO, Si3N4 and SiC.