METHOD FOR PRODUCING SNZNNICU BASED SOLDER POWDER AND SNZNNICU BASED SOLDER POWDER

摘要

A method of manufacturing an Sn-Zn-Ni-Cu based solder alloy containing Cu and Ni is provided to obtain a SnZnNiCu-based solder alloy which can achieve high joint reliability due to low degradation of joint strength by using a liquid quenching atomization method under predetermined conditions. As a method of manufacturing an Sn-Zn-Ni-Cu based solder alloy by a liquid quenching atomization method, the method is characterized in that an atomizing temperature is 500 deg.C or more. The atomizing temperature is 900 deg.C or more. The composition of raw material metals used as solder powder raw materials comprises 3 to 12 wt.% of Zn, 1.0 to 15 wt.% of the sum of Cu and Ni, and the balance of Sn and inevitable impurities to the total raw material amount. The raw material metals further contain 0.0081 to 0.2 wt.% of Al to the total raw material amount. The method comprises melting the raw material metals and rapidly quenching the molten raw material metals while injecting molten raw material metals from a nozzle by atomization gas. The atomization gas has a pressure of 1 to 15 MPa. The solder powder to be obtained has an average particle diameter of 5 to 100 mum.