Abstract: The high degree integration of electronic power technology has put forward higher requirements for heat dissipation and strength of brittle ceramic substrates carrying electronic components. Due to its excellent intrinsic thermal conductivity and mechanical properties, silicon nitride ceramics have broad development prospects in the field of high-power semiconductor device packaging. However, the thermal conductivity of Si₃N₄ that can be achieved in commercial and experimental studies is much lower than its intrinsic thermal conductivity, and how to improve the thermal conductivity of Si₃N₄ on the basis of ensuring its excellent mechanical properties is still a difficult problem. In this paper, the recent development of high thermal conductivity silicon nitride is summarized, and the influencing factors and improvement methods of the actual thermal conductivity of Si₃N₄ are emphatically discussed. At the same time, the advantages and disadvantages of several Si₃N₄ sintering processes are compared, and make a brief introduction of the current mainstream commercial Si₃N₄ ceramic substrate molding process. The development direction of Si₃N₄ ceramic substrate is prospected finally.

Key words: Si₃N₄, high thermal conductivity, ceramic substrate, lattice oxygen, density, grain growth driver, grain growth morphology, sintering process