Oct 16, 2011 
Nihon Superior Co. Ltd., a supplier of advanced soldering materials to the global market, announces that Keith Sweatman will present a paper titled “The Effect of Microalloy Additions on the Morphology and Growth of Interfacial Intermetallic in Low-Ag and No-Ag Pb-Free Solders” at the upcoming SMTA International 2011, scheduled to take place October 18-19, 2011 at the Fort Worth Convention Center in Texas. The presentation will be held during session MFX3, titled “Lower Cost Alternative Lead-Free Alloys for Electronic Assembly,” which is scheduled to take place Wednesday, October 19, 2011 from 8-9:30 a.m.
In recent times, the rising price of silver has prompted an increasing interest in the electronics industry in low- or no-Ag lead-free solders. One of the factors that is considered to have an effect on the reliability of solder joints - particularly at high strain rates such that occur in drop impact - is the intermetallic that forms between the solder and the substrate. The morphology and stability of this interfacial layer of intermetallic is, in turn, affected by the composition of the solder used to make the joint.
In this presentation, Mr. Sweatman will report on a study of the thickness morphology and growth of intermetallics formed on a copper substrate by eight alloys that are representative of the range of low- and no-Ag formulations currently used or proposed as Pb-free solders for electronic assembly. In addition to the basic constituents of Sn, Cu and Ag, these alloys included additions of Ni, Bi, Ce, Ge and P. Cross-sections were examined by SEM, and the thickness and growth at 130°, 140° and 150°C of both the Cu6Sn5 and Cu3Sn phases was monitored. While Ni was found to have a strong effect on all aspects of the interfacial intermetallics, any effects of Bi were more subtle.
Nihon Superior was founded in 1966 when it began marketing unique flux products imported from the US. The company made its mark on society by gathering the most advanced soldering and brazing technologies and products from around the world, and supplying them to companies in the metal-joining industry. A turning point for the company came when it started developing its own soldering materials and with the success of its unique SN100C lead-free solder alloy Nihon Superior has become a major player in the global market. To support the growing demand for its products, Nihon Superior has established manufacturing and sales centers in Japan, China and other Asian countries, and the United States, and formed business partnerships with companies in other markets.
