The Kester HM531 is a halide-free, organic acid, water soluble solder paste that provides users with the highest level of consistency and performance. Batch after batch, HM531 provides hr of stable stencil life, tack time and repeatable brick definition. HM531's robust printing characteristics result in consistent solder paste volume regardless of idle time, stencil life and print speed. - The activator package in the HM531 is very aggressive and provides superior wetting to OSP-coated PCBs and PdAg components. The outstanding batch consistency, anti-slump chemistry, consistent print volumes, solderability and cleanability make the HM531 an ideal water soluble solder paste for any application.