Features: --Highly Synthetic Halogen-Free Solder Paste. --Mild pH, no corrosiveness to IC or PCB. --Transparent residue, no washing needed. --Great soldering work tool for smart phone, PCB, BGA, electronic parts repairing. --High-purity rosin is the oil from the pine tree.Melted at high temperature,solid.Mainly used for soldering solder paste.