Method for forming elongated solder connections between a semiconductor device and a supporting substrate

A process for forming elongated solder terminals having hour-glass-like shapers to electrically connect a plurality of I/O solder wettable pads on a semiconductor device to a corresponding plurality of solder wettable pads on a supporting substrate comprising,

• forming a means to maintain a constant predetermined vertical spacing between said semiconductor device and said supporting substrate, said means being non-deformable at or below the temperature necessary to reflow the solder of the solder terminals,
• forming and affixing an extender formed of a low melting metal selected from the group consisting of Pb, Sn, and Pb-Sn alloy to each of said solder wettable pads on said substrate,
• positioning said semiconductor device having reflow solder mounds on said solder wettable pads over said supporting substrate with said solder mounds in registry and in contact with said solder extenders affixed to said pads on said substrate, said means to maintain vertical spacing located between and in abutting relation to said device and said support substrate,
• heating the resultant assembly to reflow said solder mounds and said solder extenders while maintaining a constant predetermined spacing thus forming a plurality of hour-glass shaped elongated connections.