ALTERNATE SOLDER BALLS FOR IMPROVING DROP/SHOCK RELIABILITY
Authors: Ahmer Syed, TaeSeong Kim, and Se Woong Cha Company: Amkor Technology, Inc. Date Published: 7/30/2008
Abstract: With the advent of large scale implementation of handheld electronic products, interconnect reliability for drop/shock loading has become a major reliability concern. The problem has exacerbated with the migration to Pb free solder alloys and selection of proper interconnect material has been a major research focus. This paper presents data on the reliability of alternate solder ball alloys as well as Polymer Core solder balls for drop/shock loading. Board level reliability tests were conducted on 0.5 and 0.4mm pitch packages with NiAu and CuOSP pad finish using polymer core solder (PCS) balls along with solder balls of different alloys. The data shows that polymer core solder balls can improve the interconnect reliability, depending on the package surface finish. Low Ag solder alloys have also shown improved drop performance over SAC305/ SAC405 solder alloys.