An electrical structure and method for forming. The electrical structure includes a first substrate comprising a first electrically conductive pad, a second substrate comprising a second electrically conductive pad, and an interconnect structure electrically and mechanically connecting the first electrically conductive pad to the second electrically conductive pad. The interconnect structure comprises a non-solder metallic core structure and a first solder structure. The first solder structure electrically and mechanically connects a first portion of the non-solder metallic core structure to the first electrically conductive pad. A second portion of the non-solder metallic core structure is thermo-compression bonded to the second electrically conductive pad.