TIN POWDER, PROCESS FOR PRODUCING TIN POWDER, AND TIN POWDER-CONTAINING ELECTRICALLY CONDUCTIVE PASTE

摘要

This invention provides a tin powder comprising fine tin particles which can easily form a fine pitched wiring circuit, has an excellent capability of filling via holes having a small diameter, and can exhibit low-temperature fusing. The tin powder is produced by placing copper powder in water, stirring the mixture to prepare a copper powder slurry, separately adding an acid to a mixed aqueous solution containing a divalent tin salt and thiourea to prepare a substitution precipitation tin solution, mixing the copper powder slurry and the substitution precipitation tin solution together so that the ratio of tin to copper in the copper powder slurry is a predetermined value, and stirring the mixed solution to cause substitution precipitation of tin on the surface of the copper powder particles.