Design of experiments to investigate reliability for solder joints PBGA package under high cycle fatigue

This paper emphasizes a rapid assessment methodology using by the design of experiments (DOE) to determine fatigue life of ball grid array (BGA) components in the random vibration environment. The most critical dynamic loading occurs when the dominant frequency approaches the natural frequency of the printed wiring board (PWB) assembly. This research has chosen to work within the PWB clamped on two opposite edges. One only needs to think of commercial personal portable electronic products such as cell phones, personal data assistants, and entertainment devices (as exemplified by the I-pod) to realize that electronic products are no longer exclusively used in a relatively benign office environment. The approach in this paper will involve global (entire PWB) and local (particular component of interest) modeling approach. In the global model approach, the vibration response of the PWB will be determined. This global model will give us the response of the PWB at specific component locations of interest. This response is then fed into a local stress analysis for accurate assessment of the critical stresses in the solder joints of interest. The stresses are then fed into a fatigue damage model to predict the life. The solution is achieved by using a combination of finite element analysis (FEA) and physics of failure to BGA damage analysis.