Paper Title
Nanoindentation Approach On Investigating The Micromechanical Properties Of Solder Joint Sn3.0ag0.5cu On Different Surface Finishes

Abstract
The present study explores the micromechanical properties of solder joint 3.0Ag0.5Cu (SAC 305) on different surface finishes, Electroless Nickel Immersion Gold (ENIG) and Immersion Tin (ImSn)through nanoindentation approach. Soldered samples of SAC305/ENIG and SAC305/ImSn were subjected to high temperature storage (HTS) at 150 °Cfor 1250 hours. The micromechanical properties changes of SAC305/ENIG and SAC305/ImSn were explored. The indentation was made on cross section of solder SAC305/ENIG and SAC305/ImSn using Berkovich diamond tip.It is observed that a clear trend of maximum depth, plastic depth, plastic work and elastic work were increased as the samples subjected to HTS for 1250 hours. The findings showed that the hardness of SAC305/ENIG and SAC305/ImSn were decreased from 0.25 GPa to 0.23 GPa and 0.18 GPa to 0.14 GPa with the HTS time, respectively. The reduced modulus for SAC305/ENIG were decreased from 91.34 GPa to 77.07 GPa while for SAC/ImSn were increased from 72.95 GPa to 84.70 GPa after 1250 hours HTS. The findings showed that there are variation of micromechanical properties of SAC305 on ENIG and ImSn. Keywords- ENIG; high temperature storage; ImSn; micromechanical properties; nanoindentation;SAC305