INTRODUCTION OF NEW COMPOSITE SOLDERS
SMU’s Research Center for Advanced Manufacturing (RCAM) has developed improved composite lead-free solders derived from Sn-Ag and Sn-Ag-Cu systems and enhanced/ reinforced with nanoparticles of various materials as well as a technique to mitigate the tin whiskers growth. Investigation has shown that copper nanoparticles will reinforce the solder itself, but they fail to strengthen the interface between the solder and substrate. Nickel nanoparticles in solders will significantly improve the solder structure and strengthen both the solder and the solder/substrate interface. It is known that the multiple layering of Ni and Sn could prolong the appearance of tin whiskers.
• High strength and longer fatigue life
• Improved thermal reliability
• Mitigate the growth of tin whiskers
• Development of lead-free solders
• Modeling and testing solder systems
•Controlling the growth of tin whiskers
• Electronics packaging
• Surface mount technology
• Any critical electronic assembly
•D.C. Lin, R. Kovacevic, et. al. (2007), An Investigation of the Influence of Nanoparticle Reinforcements on Microstructural Development in Lead Free Tin-Silver Solder. International Journal of Nanomanufacturing, Vol. 1, No. 3, 357-369.
•D.C. Lin, R. Kovacevic, et. al. (2006), Microstructural Development of a Rapidly Cooled Eutectic Sn-3.5% Ag Solder Reinforced with Copper Powder, Powder Technology. Vol.166, pp38-46.
•Dimitrovska, A. and Kovacevic, R., ”Mitigation of Tin Whiskers Growth by Applying Multiple Ni/Sn Plating Prior to the Final Sn Finish”, the Journal of Electronic Materials, Vol.38, No. 12, 2009, pp. 2516 – 2524.
•Dimitrovska, A. and Kovacevic, R., ”The Effect of Micro-alloying of Tin Plating on Mitigation of Tin
Whiskers Growth”, IEEE, the Journal of Electronic Materials, Vol. 38, No. 12, 2008, pp. 2726-2734.