Nanoindentation of Sn3.0Ag0.5Cu/ENIG Solder Joint after High Temperature Storage

Abstract

This study used nanoindentation technique in order to examine the micromechanical properties of Sn3.0Ag0.5Cu (SAC305) on Electroless Nickel Immersion Gold (ENIG) surface finished Cu substrate subjected to high temperature storage. Lead free solder paste of SAC305 were soldered on ENIG substrate by reflow soldering at 215 °C for 8 second. The soldered samples were exposed to high temperature storage at 180 °C for 0, 200, 400, 600, 800 and 1000 hours. Micromechanical properties show that the solder hardness is decreasing with the HTS time from 239.13 MPa for 0 hour to 178.96 MPa for 1000 hours while the reduce modulus results has increased from 62. 16 x 103 MPa for 0 hour to 82.13 x 103 MPa for 1000 hours. The value of hardness and reduced modulus from nanoindentation approach indicate the occurrence of plastic and elastic deformation throughout the test.