LTronics NC-447 is a no clean soldering flux paste designed for lead-free and leaded alloys. This tacky no clean flux paste uses a mix of rosin, and high grade synthetically refined resin. The flux provides fast and widespread wetting during soldering and leaves non-conductive and non-tacky residues. LT-NC-447 solder flux paste is ideal for solder touch-ups, repairs, or reworks of surface mount assemblies.