Patent ID: 7575150

Claim:
A method of soldering comprising the steps of: (A) providing a flux composition on an electrode portion of a substrate, said flux composition comprising at least one compound having at least one blocked carboxyl group selected from the group consisting of: compound (Y) obtained by reaction of a carboxylic acid anhydride compound and a hydroxy vinyl ether compound, and compound (Z) obtained by reaction of an acid anhydride and a polyhydric alcohol, followed by addition polymerization with a divinyl ether compound, wherein said flux composition is free from a compound having two or more reactive functional groups in a molecule capable of forming chemical bonds with carboxyl groups, and wherein said flux composition is non-curing; (B) providing a solder bumped electronic component; (C) placing said electronic component provided in step (B) on said substrate obtained in step (A) and (D1) subjecting the substrate with the electronic component obtained in step (C) to reflow for mounting.