Gold-Contaminated Solder-Joint Characterization for Quantifying Risk Associated with Gold Embrittlement

Circuit card assembly (CCA) reliability is dependent on solder joints, which join components to printed circuit boards (PCBs). Board users strive to mitigate risks associated with gold-embrittled solder joints. Enig Associates, Inc. (ENIG), in collaboration with Sandia National Laboratories, proposes to develop a risk-forecasting tool for quantifying the risks associated with gold-embrittled solder joints in electronic assemblies. The team will utilize existing Finite Element (FE) and kinetic Monte Carlo (KMC) tools and modeling approaches to predict the evolution of gold-embrittlement on PCB-level, surface mounted devices. FE models, developed in Comsol Multiphysics and/or ANSYS, will assess stress concentrations in the solder joint adhesion layer, as a function of time and as a result of fabrication and environmental stresses. KMC models will examine the dynamics of intermetallic diffusion in the solid and adhesion layer. Results will be used to estimate bonding area strength in the FE model and to evaluate solder joint performance under transient loads. Approved for Public Release 16-MDA-8620 (1 April 16)