SOLDER POWDER AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide solder powder which greatly improves a melting property during reflow by suppressing a composition gap caused by the non-uniformity of a structure of a metal particle, and also to provide a method for producing the same.

SOLUTION: There is provided the solder powder with an average particle diameter of ≤5 μm comprised of the metal particle 30 configured of a central nucleus 31, an intermediate layer 32 covering the central nucleus 31, and an outermost layer 33 covering the intermediate layer 32. The central nucleus 21 is comprised of one metal of silver, copper, bismuth, germanium, nickel, indium, gold or cobalt, the intermediate layer 32 is comprised of one metal of silver, copper, bismuth, germanium, nickel, indium, gold or cobalt that is different from the metal of the central nucleus 31, and the outermost layer 33 is comprised of tin. When respective volume proportions of the central nucleus 31, the intermediate layer 32, and the outermost layer 33 are made to be Vc%, Vm%, and Vo%, respectively, assuming that the volume of the metal particle 30 is 100%, and a relation of VcCOPYRIGHT: (C)2012,JPO&INPIT