SOLDER ALLOY, SOLDER PASTE AND ELECTRONIC CIRCUIT BOARD

摘要

A solder alloy which is substantially composed of tin, silver, copper, bismuth, antimony, indium and nickel. With respect to this solder alloy, the content ratio of silver is set to 0.05% by mass or more but less than 0.2% by mass; the content ratio of copper is set to from 0.1% by mass to 1% by mass (inclusive); the content ratio of bismuth is set to more than 4.0% by mass but 10% by mass or less; the content ratio of antimony is set to from 0.005% by mass to 8% by mass (inclusive); the content ratio of indium is set to from 0.005% by mass to 2% by mass (inclusive); the content ratio of nickel is set to from 0.003% by mass to 0.4% by mass (inclusive); the content ratio of tin is set to the remaining ratio; and the mass ratio of the bismuth content relative to the nickel content, namely (Bi/Ni) is set to from 35 to 1,500 (inclusive).