NO-CLEAN LOW-RESIDUE SOLDER PASTE FOR SEMICONDUCTOR DEVICE APPLICATIONS

摘要

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. The viscosity of the solvent e.g. 2, 5-dimethyl-2, 5-hexanediol or isobornyl cyclohexanol, is more than 10.000 cps at 30°C. The paste can be used for reflow soldering.