Effects of graphene oxide on the electromigration lifetime of lead-free solder joints

摘要

Electromigration (EM) is the mass transport of atoms due to electron flow, which induces a disconnect in electronic packaging. Recently, EM has received growing attention because it occurs easily when the size of joints in electronic packaging is reduced for better integration. Many researchers tried to improve the EM properties of solder joints by adding minor elements or using composites. Some studies reported that adding graphene, which is widely researched in recent years, to electronic packaging could improve the EM property. However, there is a lack of research on the EM lifetime characteristics with other materials added to the solder, such as minor elements, composites, and graphene. In this study, the effect of graphene oxide (GO) powder in Sn-3.0Ag-0.5Cu Pb-free solder paste on the EM lifetime of the solder joint was investigated. Using the fabricated solder paste and a reflow process, the printed circuit board finished with organic solderability preservative on Cu pad and Ni/Au-finished ball grid array packages with solder balls were joined. Afterwards, EM tests were performed at an elevated temperature of 130 degrees C and a current density of 1.0x10(3) A/cm(2). The EM lifetime increased as the amount of added GO powders increased. Notably, the addition of 0.2wt% GO nearly doubled the EM lifetime in the solder joint compared to that without GO.