Recent achievement in microstructure investigation of Sn0.5Cu3.4Ag lead-free alloy by adding boron

Inhomogenous microstructural coarsening sites are known to be preferred sites for initiation of creep and fatigue cracks. Thus, one of the keys to improved solder-joint reliability is the ability to control and stabilize a uniform microstructure. This study involves alloying small quantities of boron into the Sn-Cu-Ag system with the aim to improve the microstructure of these solders. Several analytical methods, such as SEM, TEM and SIMS, were employed to investigate the distribution and microstructure of alloying elements in the Sn-Cu-Ag system.