High Thermal Conductivity of Silicon Nitride Ceramics: A Review

Abstract

Silicon-nitride ceramic substrates exhibit high thermal conductivity, high electrical insulation, high mechanical strength, low expansion. The Cu-clad ceramic substrate is the key material for the encapsulation of insulated gate bipolar transistor modules. In this review, we divide the research of high thermal conductivity silicon nitride ceramics into four stages: 1) exploration of thermal conductivity with different sintering additives; 2) using the anisotropy of silicon nitride grains to improve the thermal conductivity, through the addition of silicon nitride grain seeds combined with tape casting technology, sintered to obtain a thermal conductivity of 155W/(m·K) silicon nitride, and with the development of the strong magnetic field alignment technology in the later stage, the thermal conductivity can be increased to 176W/(m·K); 3) using sintered of reaction-bonded silicon nitride technology to improve thermal conductivity, thermal conductivity can be increased to about 180W/(m·K); 4) the application of high thermal conductivity silicon nitride ceramic substrate. Finally, future preparation methods and applications of high thermal conductivity silicon nitride ceramics are envisioned.