A novel 96.5Sn3Cu0.5Mn nanosolder with enhanced wettability applied to nanosoldering of WO3 nanomaterial

Nano-soldering relying on a sacrificial nanosolder, is a flexible interconnection technique, having promising applications in joining nanosized functional materials; that is an essential step in the assembly of nano-devices. In a soldering, the wettability is important in the bonding of two nanomaterial, which determines the quality of the junction. Tungsten trioxide nanomaterial has unique characteristics such as electro-, opto-, gaso-chromic. To assemble this nanomaterial into functional nano-devices, a superior nanosolder is necessary. The conventional SnCu nanosolder has been chosen, but its wetting on WO3 is unsatisfactory. Here, our study indicates that the SnCu wettability on WO3 material has been improved greatly by adding minor manganese, in which the contact angle has a significant change from 73.2° to 41.7°. Then the wetting mechanism is investigated by observing the soldering interface. Lastly, a more robust and higher-reliable junction has been obtained by thermal soldering two individual WO3 nano-objects into a cross-shaped pattern.