Kester 952-S is a halide-free, non-rosin organic flux designed specifically for use in tabber and stringer equipment of PV module industry by soldering tabs to cell contacts. 952-S could be applied directly to interconnecting ribbon by hand soldering or auto-equipment with tabber and stringer soldering system, by dipping or spraying. The extremely low solids content (around 2%) and nature of the activator system results in practically no residue left on the cell after soldering. Cell are dry and cosmetically clean as they exit the tabber and stringer machine. 952-S has a wider operating window varying with temperature range, and can be used in SnPb, SnAgPb and lead-free alloys.