Abstract: A thermally curable adhesive composition that includes a fluxing agent that also acts as an adhesive is provided. The composition includes: (a) a fluxing agent represented by the formula RCOOH, wherein R comprises a moiety having two or more carbon--carbon double bonds; (b) optionally, an effective amount of a crosslinkable diluent; (c) optionally, an effective amount of a source of free radical initiators; and (d) optionally, an effective amount of a resin to react with remnant carboxylic acid moieties. The composition can be applied directly onto the surface(s) of devices that are to be joined electrically and mechanically. These devices include, printed circuit substrates, connectors, components, cables, and other electrical devices having metallization patterns to be soldered together by means of a solder-bumped pattern on one or both surfaces. Alternatively, a solder paste, comprising solder powder mixed with the fluxing agent of the present invention can be used.