Feb 07, 2012 
Nihon Superior Co. Ltd., a supplier of advanced soldering materials to the global market, announces that its Senior Technical Advisor Keith Sweatman will present the paper titled “Effect of Cooling Rate on the Intermetallic Layer in Solder Joints” at the upcoming IPC APEX Expo, scheduled to take place February 28-March 1, 2012 at the San Diego Convention Center in California. This presentation will be held during the session titled “Solder Joint Morphology” on Wednesday, February 29, 2012 from 9-10 a.m.
The intermetallic layer plays a critical role in the reliability of solder joints and Mr. Sweatman will report the results of a study on the effect of cooling rate and isothermal ageing on the transformation of the Cu6Sn5 phase from the hexagonal to monoclinic form. This study was coupled with measurements of the expansion of the hexagonal and monoclinic forms of Cu6Sn5 as a function of temperature.
The change in volume associated with the phase transformation can create stresses sufficient to initiate cracking in the intermetallic layer. A significant conclusion of these studies is that by choosing the temperature at which the transformation occurs in the metastable hexagonal Cu6Sn5 created by rapid cooling, the volume change and hence the risk of cracking can be minimized.
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.
