Investigation of dynamic characteristics and fatigue life prediction of Pb free solder material under random vibration

Abstract

Electronic packages are employed in diverse industries, including automotive, aerospace, and defense. However, their susceptibility to failure arises from exposure to uncontrolled operating conditions, particularly vibrations.Therefore, an investigation has been conducted to explore the effect of vibration in fatigue life of SAC305 lead free solder material employed in Printed Circuit Board (PCB) assembly with ball grid array (BGA) 144 electronic package. Finite Element Analysis (FEA) of a printed circuit board with BGA 144 electronic package was conducted to find their dynamic characterisics like natural frequencies and their mode shapes. Experiments were conducted to validate the numerically developed model, where first, second and third modes shapes from FEA and experimental results were compared. In addition, random vibration analysis was performed using numerical simulation where individual solder balls were analysed for stress distribution and experiments were conducted on specially fabricated PCBs using electro dynamic shaker for validation. Analysis shows that the failure was prominent at the solder balls located at the corner of the package. Further, Minor's rule was used to estimate the fatigue life of the Pb free solder material in BGA 144 package.