Characterize the Microstructure and Reliability of Ultra Fine Pitch BGA Joints
The solder ball pitch of BGA packages in mass production now is normally above 0.5mm. To fulfill the future demand of package miniaturization, the 0.4mm ultra fine pitch BGA solder joint was researched in this paper. The solder volume shrinkage along with the ball pitch decrease was found to affect the joint microstructure, which could be characterized in two aspects: the Sn dendrites in bulk solder became finer, and the so called “cross-interaction in interfacial layer occurred. The joint reliability variation due to volume shrinkage was paid much attention to. Four different alloy content solder balls were evaluated through thermal cycling and drop reliability test, to find out the most proper soldering materials on both NiAu and OSP pad finishes. Our research result indicated that reliable ultra fine pitch joint could be gotten if proper materials and processes adopted. Sn1.0Ag0.5Cu0.02Ni was recommended as the solder alloy composition for the ultra fine pitch BGA usage.
Lei Wang Zhenqing Zhao Qian Wang Jaisung Lee
Samsung Semiconductor China R&D Co., Ltd.No. 15, Jin Ji Hu Road, Suzhou Industrial Park, Suzhou, Chi Samsung Semiconductor China R&D Co., Ltd. No. 15, Jin Ji Hu Road, Suzhou Industrial Park, Suzhou, Ch
国际会议
北京
英文
674-678
2009-08-10（万方平台首次上网日期，不代表论文的发表时间）