Inventors:
Peter Jeffrey Brofman - Hopewell Junction NY
Shaji Farooq - Hopewell Junction NY
John U. Knickerbocker - Hopewell Junction NY
Scott Ira Langenthal - Hyde Park NY
Sudipta Kumar Ray - Wappingers Falls NY
Kathleen Ann Stalter - Hopewell Junction NY
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H01L 2302
US Classification:
257678, 257734, 257773, 257779, 257723, 257724, 257772, 438106, 438108, 438128, 438121, 438618, 438666, 438612
Abstract:
A method of forming non-spherically shaped solder interconnects, preferably conical, for attachment of electronic components in an electronic module. Preferably, the solder interconnects of the present invention are cone shaped and comprise of depositing a first solder followed by a second solder having a lower reflow temperature than the first solder. Warm placement of the electronic component at a somewhat elevated temperature than room temperature but less than the solder reflow temperature reduces the force required during placement of a semiconductor chip to a substrate. After warm placement, reflow of the module occurs at the lower reflow temperature of the second solder. The conical shape of the solder interconnects are formed by a heated coining die which may also coin a portion of the interconnects with flat surfaces for stand-offs. The ability of the cone shaped solder interconnects to meet the opposing surface of a chip or substrate at different heights accommodates the camber typically associated with chip and substrate surfaces.