Chemical and Biomolecular Engineering Research and Publications
Date of this Version
11-5-1991
Abstract
An improved solder/polymer fluxless composite paste interconnection material having a low reflow temperature to form electrical contacts having good bonding strength and low contact resistance. The present pastes comprise a major proportion of a meltable metal alloy powder filler, free of noble metals and preferably free of lead, a minor proportion of a solution of a temperature-stable thermoplastic polymer having a softening temperature above the melting temperature of the metal powder filler in a volatile solvent which evaporates during reflow, and a minor proportion of a fluxing agent having a boiling point lower than the reflow temperature of the composition and higher than the melting point of the eutectic alloy powder filler. An oxide-free, partially coalesced metal alloy connection is obtained, which is polymer strengthened and reworkable at a low reflow temperature, per se, or in the presence of polymer solvent.
Comments
The inventors of this patent are:Huang; Wu-Song (Poughkeepsie, NY), Khandros; Igor Y. (Peekskill, NY), Saraf; Ravi (Croton-on-Hudson, NY), Shi; Leathen (Yorktown Heights, NY) .Any relevant information about this patent can be obtained from the corresponding website of United states patents. united states patent no 5,062,896