Joint structure, joining method, wiring board and method for producing the same

摘要

A joint structure of the present invention includes a conductive member containing copper as a major component thereof, an electrode member containing copper as a major component thereof, and a joint portion formed by fusion welding the conductive member and the electrode member with a brazing material containing tin as a major component thereof and containing substantially no copper, wherein the amount of copper atoms contained in the alloy in the central part of the joint portion is higher than that in the outer circumference part.