Impact of drop-in lead free solders on microelectronics packaging

Lead-free solders and soldering technology will be a revisited concern in microelectronics packaging challenges to meet the demands of wafers-level packaging and 3D packaging operations where greater demands will be made on soldering smaller pads sizes and the high expectations of solder joint strength and long-term reliability. This paper reports on the drop-in lead-free solder approach and will provide characterization research results on Sn-Ag-Cu-In drop-in solder material composition, wetting and assembly characteristics and mechanics properties for stress-strain and creep performance compared to Sn3.8Ag0.7Cu solder.