Patent ID: 7906425
Filing Date: 2011-03-15
Classification: H01L,Y10T

Abstract:
1. A process comprising: providing a semiconductor device including a bond pad, and an under bump metallurgy overlying the bond pad; forming a fluxless electrically conductive solder structure over the under bump metallurgy, and wherein the solder structure includes an outer layer including tin oxide; converting the tin oxide to tin oxy-halide to reduce the melting temperature of the outer layer; and heating to reflow in the absence of flux the solder structure including reflowing a bulk of said solder structure and cooling the same to provide an electrically conductive solder bump with a truncated spherical shape on the under bump metallurgy, said heating following said converting, said electrically conductive solder bump having a different bulk shape than said electrically conductive solder structure, said step of heating to reflow without joining said solder structure to another structure.