Patent ID: 7261760

Claim:
Powder comprising particles of an alloy having a separated structure obtained by spray-quenching molten alloy and consisting of two regions having different compositions from each other, wherein one region is a core portion and one region is a surface portion surrounding the core portion and comprises a lead-free solder composition and the core portion has a composition excellent in electrical conductivity and heat conductivity wherein the alloy is a Cu—Bi—X alloy comprising 5 to 70% by mass of Bi and X being one or more elements selected from a group consisting of 0.1 to 30% of Sn, 0.1 to 30% of In, 0.1 to 30% of Ag, 0.1 to 30% of Sb, 0.1 to 30% of Zn and 0.1 to 30% of Al each being represented by % by mass.