Study on Tungsten Metallization and Interfacial Bonding of Silicon Nitride High-Temperature Co-Fired Ceramic Substrates

For the first time, Si₃N₄ HTCC has been prepared using W as the metal phase by high-temperature co-firing (1830 °C/600 KPa/2 h) as a potential substrate candidate in electronic applications. It was discovered that the addition of Si₃N₄ to the W paste has a significant impact on thermal expansion coefficient matching and dissolution wetting. As the Si₃N₄ content increased from 0 to 27.23 vol%, the adhesion strength of W increased continuously from 2.83 kgf/mm² to 7.04 kgf/mm². The interfacial bonding of the Si₃N₄ ceramic and the conduction layer was discussed. SEM analysis confirmed that the interface between Si₃N₄ and W exhibited an interlocking structure. TEM, HRTEM and XRD indicated the formation of W₂C and W₅Si₃ due to the interface reactions of W with residual carbon and Si₃N₄, respectively, which contributed to the reactive wetting and good adhesion strength between the interface. Suitable amounts of Si₃N₄ powder and great interfacial bonding were the main reasons for the tough interfacial matching between the Si₃N₄ ceramic and the conduction layer.