Interfacial morphology evolution of a novel room-temperature ultrasonic bonding method based on nanocone arrays

摘要: Abstract The evolution of interfacial morphology is investigated in joints bonded by a newly developed ambient-temperature ultrasonic bonding process based on Ni nano-cone arrays. This confirmed two types void at the interface: Type I concave area among cone-like nanocrystals, and II top nanocrystals. By increasing pressure or time, voids can be eliminated; however, threshold exists for voids, below which time accelerates formation voids. At pressures above this threshold, other hand, results shrinkage Varying was also found to induce change from ladder-like finally planar structure. In way, critical obtaining solid joint 7 MPa.