Rosin Based Solder Paste

• Rosin based (R) solder paste is comprised of rosin (an emulsifying agent obtained from pines and other plants) and solvent. This type of solder paste has low activity and is suitable for cleaning and easily soldered surfaces like copper, silver and gold. The residue left after soldering is non-conductive and can stay on many kinds of materials without damaging them or can be easy to clean from bonded surfaces using a suitable solvent.
  
  

Rosin Mildly Activated Solder Paste

• Rosin mildly activated (RMA) solder paste contains rosin, solvent and an activator. It is best suited for easily-soldered surfaces. Most types of RMA pastes are non-corrosive and non-conductive, allowing them to be left on many kinds of materials without damaging them; however, the cleaning requirements may vary according to flux activity and type of materials used in the soldering process. RMA solder is easy to clean from bonded surfaces using an appropriate solvent.
  
  

No-Clean Solder Paste

• No-Clean (NC) solder paste is comprised of rosin, solvent and an activator. It is has a low-to-moderate activity level, making it well-suited for easily-soldered surfaces like copper, silver and gold. Designed to leave a clear, hard, non-corrosive and non-conductive residue, NC solder paste can stay on most surfaces without damaging them. Surface residue is removable using an appropriate solvent, although it is sometimes more difficult to remove than a RMA soldering paste.
  
  

Water-Soluble Solder Paste

• Water-soluble (WS) solder paste contains organic acids, thixotrope (a thick gel that becomes liquid when heated) and solvent. There are several types of WS solder paste, providing a wide range of activity levels for diverse soldering surfaces and materials. This makes it a dependable all-purpose option that is easy to clean from bonded surfaces using water.
  
  

Rosin Activated Solder Paste

• Rosin activated (RA) solder paste contains rosin, solvent, and aggressive activators, giving it a higher activity rate designed for more difficult to solder surfaces like iron, nickel, titanium and steel. The residue left on bonded surfaces is highly corrosive and conductive, and should be cleaned from sensitive materials with an appropriate solvent soon after assembly.