Method for producing SnAgCu based solder powder and method for preparing paste for solder using this powder

摘要

The present invention is directed to an Sn—Ag—Cu-based solder powder which comprises solder powder having an average particle size of 5 μm or less, and a dried material of a solution of hydroxybenzoic acid or an ester thereof having a melting point of 250° C. or lower being attached onto a surface of the solder powder as an additive, wherein the additive is preferably salicylic acid, ethyl 3,4-dihydroxybenzoate or ethyl 3,5-dihydroxybenzoate, an attached amount of the additive is preferably 0.01 to 1.0 part by mass based on 100 parts by mass of the total amount of the components of tin, silver and copper contained in the solder powder, a content of the silver is 0.1 to 10% by mass when the total amount of the components of tin, silver and copper is made 100% by mass, a content of the copper is 0.1 to 2.0% by mass when the total amount of the components of tin, silver and copper is made 100% by mass, and a remainder being tin.