The Kester NF372-TB is a zero halogen, no-clean, low solids liquid flux designed to withstand long dwell times and high preheat temperatures needed in thick board assemblies. NF372-TB is classified as ROL0 flux under IPC J-STD-004B. - Sustained activity within the flux allows for good barrel fill in challenging applications, such as reflowed copper OSP boards or with difficult to solder components. NF372-TB residues are minimal, clear and non-tacky for improved cosmetics.