Patent ID: 6615484
Filing Date: 2003-09-09
Classification: B23K,H01L,Y10T

Abstract:
A method of electrically connecting an electrical component having a plurality of spaced apart electrical component electrical terminations to a substrate having a plurality of spaced apart substrate electrical terminations corresponding to the terminations of said electrical component to form a plurality of spaced apart electrical connections and then interfilling said electrical and substrate components with an encapsulant composition sandwiched therebetween to encase said spaced apart electrical connections comprising:a) forming spaced apart electrical connections of said spaced apart component electrical terminations to said corresponding spaced apart substrate electrical terminations with solder at reflow soldering temperature utilizing a cycloaliphatic epoxy-based fluxing agent that leaves a cycloaliphatic epoxy-based fluxing agent residue that is partially cured on said spaced apart electrical connections and leaves open space between the spaced apart electrical connections with cycloaliphatic epoxy-based fluxing agent residue thereon; b) filling said open space between said spaced apart electrical connections with partially cured cycloalinhatic epoxy-based fluxing agent residue thereon with an epoxy underfill encapsulant that co-cures with the cycloaliphatic epoxy-based fluxing agent residue; and then c) co-curing said epoxy underfill encapsulant and cycloaliphatic epoxy-based fluxing agent residue to form a bond at the interface of said epoxy based underfill encapsulant and cycloaliphatic epoxy-based fluxing agent residue.