This document describes Indium WS-3543, a low-viscosity semiconductor-grade flux for wafers up to 300mm, suitable for SnPb and lead-free processes.
Indium WS-3543 is a low-viscosity semiconductor-grade flux optimized to generate uniform, non-oxidized solder joints on wafers with a diameter not exceeding 300mm (12 inches). The formulation is designed to prevent tin starvation during the soldering process and allows for easy removal without residue after multiple application/reflow/cleaning cycles.
The flux is water-soluble and halogen-free, compatible with both SnPb and lead-free soldering processes. It can be applied using standard spray or spin-coating techniques. For spin coating, initial rotation speed is used to ensure uniform distribution, followed by speeds between 15rpm and 800rpm depending on the application. Spray application requires a supply sufficient for 8 hours, with the spray gun needing frequent cleaning to maintain purity. This manual is written in Chinese.
The flux is optimized for wafers with a diameter of up to 300mm (12 inches).
The recommended spin speed range is from 15rpm to 800rpm.
Ideal spray cleaning requires a pressure of over 60psi.