Copper-containing tin powder, mixed powder containing the copper-containing tin powder, method for producing the copper-containing tin powder, and conductive paste using the copper-containing tin powder or the mixed powder

摘要

It is an object to provide a copper-containing tin powder having excellent capabilities in forming fine wiring circuits and filling via holes with ability in bond by melting at a lowtemperature. In order to achieve the object, itisproduced from a copper powder as a starting material by a wet substitution process and it contains remainder of copper un-substituted at 30% by weight or less. The change rate of properties of the copper-containing tin powder, e.g. an average primary particle size or the like is in the range from -20 to +5% with respect to the starting copper powders. The copper-containing tin powder is produced by a wet substitution process in which a copper powder is brought into contact with a plating solution for tin substitution to make copper component constituting the copper powder dissolve with simultaneous substituted deposition of tin.