A study of nanoparticles in Sn-Ag based lead free solders

Co, Ni, Pt, Al, P, Cu, Zn, Ge, Ag, In, Sb or Au inclusions in Sn-Ag based lead free solders were evaluated to study if these nanoparticles can reduce the growth of intermetallic compounds after four time reflow processes and thermal aging. Also, these nanoparticles were studied if they can reduce the frequency of occurrence of intermetallic compound fractures in high impact pull tests. In addition to intermetallic compound analyses, these nanoparticle effects on solder ball hardness were studied if nanoparticles affects solder hardness and displacement in drop tests. Finally, these nanoparticle effects on drop test performance were studied. This study found that Co, Ni and Pt were very effective for the growth of intermetallic compounds and drop test performance compared to Cu, Ag, Au, Zn, Al, In, P, Ge and Sb. (c) 2007 Elsevier Ltd. All rights reserved.