Solder paste and printed circuit board

摘要

In a solder paste formed by blending an alloy powder and a flux, the alloy powder is a powder mixture formed by mixing at least one powder of a Sn—Zn based alloy and at least one powder of a Sn—Ag based alloy. The alloys powders are blended so that the composition of the powder mixture is 5-10 mass % of Zn; 0.005-1.5 mass % of Ag; optionally at least one of 0.002-1.0 mass % of Cu, 0.005-15 mass % of Bi, 0.005-15 mass % of In, and 0.005-1.0 mass % of Sb; and a remainder of Sn.