Reaction between Sn-In Solder and Under Bump Metallurgy
Reactions between 48Sn-52In solder and under bump metallurgies(UBM) such as 100nmTi/8µm Cu and 300nm Al/400nm Ni(V)/400nm Cu have been investigated, and the shear strength of 48Sn-52In solder bumps on each UBM has been evaluated. While intermetallic compounds with two different morphologies were continuously thickened on Ti/Cu with repeating the reflow process, the intermetallics on Al/Ni(V)/Cu spalled into the solder with increasing the number of reflow times. The solder bumps on Ti/Cu exhibited higher shear strength than those on Al/Ni(V)/Cu.
S.-G. Kang and T. Kobayashi
J.H. Choi et al., "Reaction between Sn-In Solder and Under Bump Metallurgy", Materials Science Forum, Vols. 449-452, pp. 401-404, 2004