Vibration Induced Fatigue Life Estimation of Corner Leads of Peripheral Leaded Components

Abstract

The rapid advancement of integrated circuits and associated electronic technologies have placed increasing demands on electronic packaging and its material structures in terms of the reliability requirements. In addition to the thermally induced stresses, electronic packages often experience dynamic external loads during shipping, handling, and/or operation. This is especially important for automotive, military, and commercial avionics operating environments. These dynamic loads give rise to large dynamic stresses in the leads causing fatigue failures. For peripheral leaded packages the corner leads are the most highly stressed leads. This paper addresses the determination of the out-of-plane displacement of the corner leads of peripheral leaded components when the local peripheral leaded component/board assembly is subjected to bending moments in two directions. The solution is achieved by using a combination of Finite Element Analysis (FEA), Design of Experiments (DOE), and analytical techniques. The out-of-plane displacement can then be applied as a boundary condition on a local lead model to determine the stresses which in turn can be used to estimate the fatigue life.