Encapsulant with fluxing properties and method of use in flip-chip surface mount reflow soldering

摘要

Encapsulated electrical component assemblies and methods of electrically connecting an electrical component having a plurality of component electrical terminations to a component carrying substrate having a plurality of substrate electrical terminations at surface mount reflow soldering conditions is described. The electrical and substrate components have an encapsulant-forming composition sandwiched therebetween and encasing said pluralities of component and substrate electrical connections. The described invention relates to using an encapsulant-forming composition comprising a thermosetting resin (preferably an epoxy resin) and a cross-linking agent (preferably an anhdride) for said resin that cross-links said resin and that also acts as a fluxing agent and optionally includes a catalyst for initiating cross-linking at required conditions. The gel point of the encapsulant-forming composition is reached after solder melt.