a no - clean low residue solder paste is described for die - attach dispensing or fine pitch printing of semiconductor devices . the solder paste has a homogeneous consistency with no tendency to paste separation . the ultimately remaining residue is clear and crystal like and is compatible with further processing steps without prior cleaning with a solvent to remove flux residue . the solder paste comprises a relatively low amount of rosin in combination with a viscous solvent system , thixotropic agents , activators , additives and optionally plasticizers .