Forming a disordered atomic layer to bond TiN or AlN ceramic with Sn9Zn metal under ultrasonication

A disordered atomic layer instead of traditional intermetallic compounds is formed in the bonding interface of ceramic and metal in the metallization of ceramics under ultrasonication. A deep understanding of the bonding mechanism between poor-wetted ceramics and low-temperature metals remains limited with regard to high metallization efficiency and nanoscale bonding structure. In this work, the metallization of AlN and TiN ceramics was realized using Sn9Zn metal with the aid of ultrasonication. The microstructure, energy, and element sources of the ceramic/metal interface were analyzed. Results show that a nanoscale amorphous layer is formed between the ceramics and the metal, and this layer can bond easily with AlN or TiN and Sn9Zn because of the irregular arrangement of its atoms. Some dispersed nanocrystals are also present in the amorphous bonding layer. The thermal effect of ultrasonic cavitation produces a high temperature above 106 K, which provides the energy for the bonding of AlN or TiN with Sn9Zn. O and Zn accumulate in the Sn-9Zn/AlN bonding layer. Zn originates from Sn9Zn. O could be from the O2dissolved in the liquid solder or the O2adhering to the ceramic. A small amount of AlN decomposes because of its high ΔG of decomposition. However, TiN decomposes into Ti and N2under the extreme condition caused by ultrasonic cavitation. The accumulated Ti in the Sn-9Zn/TiN bonding layer originates from TiN. The source of the accumulated O is the same as that of Sn-9Zn/AlN bonding layer.