Microstructure, electric flame-off (EFO) characteristics and tensile properties of silver-lanthanum alloy wire

Silver has potential for application in the electronic packaging industry because of its great electrical and thermal properties and lower price compared to that of gold. Silver oxidizes easily, so doping lanthanum to form Ag-La alloy improves its anti-oxidation capacity. In this study, the microstructure, tensile properties, electronic flame-off (EFO) characteristics, and fusing current of Ag-La alloy wire (phi = 20 mu m) are studied. Samples annealed at three temperatures (325 degrees C, 375 degrees C, and 425 degrees C) are analyzed. According to the experimental results, after annealing at 425 degrees C, Ag-La alloy wire recrystallized, giving it a tensile strength similar to that of pure silver wire and a uniform structure. Doping lanthanum reduced the diameter of free air balls (FABs) in the EFO process. The fusing current of Ag-La wire was about 0.45 A, and the grains of Ag-La wire grew to the size of the wire diameter when a 0.4A current (90% fusing current) was applied for a long time. Ag-La alloy wire can be used in the electronic packaging industry. (C) 2014 Elsevier Ltd. All rights reserved.