METHOD OF SOLDERING AN ELECTRONIC COMPONENT TO A SUBSTRATE WITH THE USE OF A SOLDER PASTE COMPRISING A LEAD-FREE SOLDER ALLOY CONSISTING OF SN, BI AND AT LEAST ONE OF SB AND MN

摘要

An electronic component package provided with an exposed die pad and a plurality of contact pads at least partially present on a bottom side thereof (for example, a quad-flat no lead (QFN) type package) is soldered to a substrate so that the contact pads and the die pad are soldered to associated contacts on the substrate by reflowing a solder paste composition comprising a lead-free solder alloy and a halide-free flux, the lead-free solder alloy having an alloy composition consisting of 58.0-62.0 wt% of tin (Sn), 38.0-41.0 wt% of bismuth (Bi) and either 0.01-1 wt% of manganese (Mn) or 0.01-2 wt.% of antimony (Sb) and 0-1.0 wt% of manganese (Mn), the lead-free solder alloy being free of nickel (Ni) and free of silver (Ag) and the solder alloy having a particle size in the range of 10-40 µm as defined by sieve analysis.