abstract |
The invention relates to a lead-free solder paste comprising a solder paste flux and solder alloy particles that are substantially lead-free wherein the solder paste flux comprises resin dissolved in a solvent and also includes undissolved resin particles less than 25 μm in size homogenously dispersed therein to provide improved solder alloy powder coalescence and substrate surface wetting while maintaining appropriate solder paste rheology for use in printed circuit board assembly processes. |