Effect of multilayer thin film on interfacial growth at the solder joint interface - An application of nanotechnology in environment friendly electronic materials

Reliability of Pb free solders in manufacturing of miniaturized electronic device has got significant attention of the researchers in recent times. In this work we report some important development on improving the reliability of lead free solder joints. Pb free solder joints have been developed with two different configurations using Sn3.5Ag0.5Cu (SAC305) and SAC305 in association with multilayered thin film of Sn. In order to address different premature failure issues in electronic devices, we have introduced transient liquid phase soldering (TLPS) technique for the processing of more reliable solder joints. Scanning electron microscopy (SEM), EDX spectroscopy has been used for microstructural characterization. Source measuring unit fitted with four probe station have been used for the electrical property determination. Multilayered thin film structure for making the joints have been found to beneficial towards controlling the interfacial intermetallic layer thickness and electrical conductivity across the joint interface.