LEAD-FREE SOLDER FLUX AND LEAD-FREE SOLDER PASTE

摘要

The main purpose of the present invention is to provide a flux which can produce a lead-free solder paste having excellent viscosity stability and displaying good wettability even after atmospheric soldering. A lead-free solder flux has a bromine atom concentration of 400 to 20,000 ppm per 0.1 g, and 0.01 to 0.7 wt% of an amine-based compound (a) represented by general formula (1) H2N-(CH2)n-X-(CH2)n-NH2 (wherein, n is an integer between 1 and 6, and X is -NH-CH2CH2-NH- or piperazine residue).