Abstract: 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.
Type:
Grant
Filed:
June 30, 2006
Date of Patent:
August 3, 2010
Assignee:
W.C. Heraeus Holding GmbH
Inventors:
Quan Sheng, Muriel Thomas, Jens Nachreiner