Influence of temperature on the soldering process of CLCC-3 package components using AuSn20 solder

Abstract

In this study, a CLCC-3 shell and a cover were connected via soldering with AuSn20 as the solder. An Au-Sn eutectic reaction occurred during the sealing process. At high soldering temperatures, only the eutectic ζ′-Au5Sn and δ-AuSn phases remained. At the interface between the solder and the Au/Ni coating, Ni entered Au5Sn and AuSn to form (Au,Ni)5Sn and (Au,Ni)Sn and Au entered the lattice of the Ni3Sn2 phase to form the ternary compound (Ni,Au)3Sn2. The experimental results demonstrated that at a soldering heating plate temperature of 320 °C, the structure of the soldering area was compact and there were no holes in the soldering area. Under these conditions, the macroscopic appearance of the product improved, the solder was sufficiently melted, and the cover plate was well infiltrated, which resulted in the formation of a good, dense connection with the base plate.