One-Step Underfill 688 is a non-odorous, low surface tension, reworkable one component epoxy resin designed as a one-step underfill for flip chip, CSP, BGA and µBGA assemblies. Acts as a flux and an underfill. May be applied directly after the SMT printing process and cured during the standard Pb-free reflow process. Can be used in mixed alloy solutions, such as Pb-free BGA on a tin lead board. Is said to offer reliability through high Tg, low CTE, and good fill with no voiding. Is compatible with no-clean flux residues. May be reworked at 120°C. Viscosity reportedly remains stable throughout shelf life. Wets to OSP, ENIG, immersion silver and immersion tin board surfaces.
 
AIM, www.aimsolder.com