Reliability Assessment of Lead-contained and Lead-free BGA Solder Joints under Cyclic Bending Loads

굽힘 하중하에서 유연 및 무연 솔더 조인트의 신뢰성 평가

  • Kim Il-Ho (Department of Mechanical Engineering, KAIST) ;
  • Lee Soon-Bok (Department of Mechanical Engineering, KAIST)
  • 김일호 (한국과학기술원 기계공학과) ;
  • 이순복 (한국과학기술원 기계공학과)
  • Published : 2006.03.01


Mobile products, such as cellular phones, PDA and notebook, are subjected to many different mechanical loads, which include bending, twisting, impact shock and vibration. In this study, a cyclic bending test of the BGA package was performed to evaluate the fatigue life. Special bending tester, which was suitable for electronic package, was developed using an electromagnetic actuator. A nonlinear finite element model was used to simulate the mechanical bending deformation of solder joint in BGA packages. The fatigue life of lead-free (95.5Sn4.0Ag0.5Cu) solder joints was compared with that of lead-contained (63Sn37Pb). When the applied load to the specimen is small, the lead-free solder has longer fatigue life than lead-contained solder. The fatigue crack is initialized at the exterior solder joints and is propagated into the inner solder joints.