Title :
Thermo-mechanical properties and creep deformation of lead-containing and lead-free solders
Author :
Schubert, A. ; Walter, H. ; Dudek, R. ; Michel, B. ; Lefranc, G. ; Otto, J. ; Mitic, G.
Author_Institution :
Fraunhofer-Inst. for Reliabilty & Microintegration, Berlin, Germany
Abstract :
For a long time, both high Pb-Sn and eutectic 63Sn-37Pb have been the suitable materials for the interconnection of electronic components because of their low cost and appropriate physical properties. Due to environmental awareness and health hazards caused by lead in the solders, large efforts have been made to develop a lead-free soldering technology. Among the large variety of lead-free solders, the Sn-Ag alloys are expected to be the best candidates. Furthermore, from a reliability point of view, there has been interest in the improved thermal fatigue resistance of solder interconnects. Therefore, in this study two lead-free solder alloys (Sn96.5Ag3.5, Sn95.5Ag3.8Cu0.7) and one lead-containing solder alloy (Sn59Pb40Ag1) were investigated and compared with each other in order to give an estimation of the creep resistance of the lead-free solders. These investigations were focused on mechanical and physical properties (coefficient of thermal expansion, Young´s modulus) as well as on the microstructural appearance of the solder. The mechanical and thermomechanical behavior of the solders was examined by TMA, DMA, and creep tests
Keywords :
Young´s modulus; assembling; copper alloys; creep; creep testing; environmental factors; health hazards; interconnections; lead alloys; mechanical testing; packaging; silver alloys; soldering; thermal expansion; thermal stress cracking; tin alloys; DMA; Sn-Ag alloy; Sn-Ag solder alloy; Sn-Ag-Cu solder alloy; Sn-Pb-Ag solder alloy; SnAg; SnAgCu; SnPb; SnPbAg; TMA; Young´s modulus; coefficient of thermal expansion; creep deformation; creep resistance; creep tests; electronic components; environmental awareness; eutectic Sn-Pb solder; health hazards; high Pb-Sn solder; interconnection; lead content; lead-containing solder alloy; lead-containing solders; lead-free solder alloys; lead-free soldering technology; lead-free solders; mechanical behavior; mechanical properties; microstructural appearance; physical properties; reliability; solder cost; solder interconnects; thermal fatigue resistance; thermo-mechanical properties; thermomechanical behavior; Costs; Creep; Electronic components; Environmentally friendly manufacturing techniques; Fatigue; Hazards; Lead; Soldering; Thermal resistance; Thermomechanical processes;
Conference_Titel :
Advanced Packaging Materials: Processes, Properties and Interfaces, 2001. Proceedings. International Symposium on
Conference_Location :
Braselton, GA
Print_ISBN :
0-930815-64-5
DOI :
10.1109/ISAOM.2001.916562
