Abstract: A silver-coated copper powder includes copper core particles and a silver coat layer located on the surface of the core particles. When S1 is a BET specific surface area (m2/g) of the silver-coated copper powder; S2 is a specific surface area (m2/g) calculated from a particle diameter D50 obtained by the analysis of a microscopic image of the silver-coated copper powder; and t is a thickness of the silver coat layer, the silver-coated copper powder satisfies Expression: (S1/S2)?0.005×t+1.45. The silver-coated copper powder has a volume cumulative particle diameter D50L at a cumulative volume of 50 vol % as measured by laser diffraction-scattering method of 0.01 to 100 ?m.

Abstract: The disclosed composite copper particle includes a core particle including copper, and a coating layer including a copper-tin alloy and formed on the surface of the core particle, the composite copper particle having a particle diameter at 50% cumulative volume in the particle size distribution of 0.1 to 10.0 ?m. The alloy is preferably CuSn. The ratio of tin to the the composite copper particle is preferably 3.0 to 12.0 mass %. The composite copper particle is suitably obtained by a method including a step of mixing a reducing agent for tin and an aqueous slurry containing a tin source compound and core particles which include copper, to form a coating layer including a copper-tin alloy on a surface of the core particles.