Abstract
Pb-free soldering and the use of electrically conducive adhesives in the electronics industry are a segment of the global trend towards a lead-free environment. In comparison to lead-free solders, current commercial isotropic conductive adhesives are characterized by lower conductivity and need much more time for curing. Usually, a few minutes at are enough only for precuring. In this paper we describe the developed family of formulations with a curing time of several seconds at . There are single-component formulations, solvent-free type, prepared in a special way on the base of the common, accessible resins. They have very convenient handling properties; e.g., no drying on open screen during printing process. Viscosity depends on the resin and may be intentionally changed. Shelf life for all these formulations is about at room temperature in closed containers. Refrigeration is not necessary. Unfortunately, the material needs the highest quality and purity of electronic grade silver fillers. The total permitted level of impurities is estimated as less than . However, this is, rather, an advantage of the silver-filled adhesives.
