Effect of ESD Layout on the Assembly Yield and Reliability

The paper investigated the thin film stress effect on the wire-bond assembly yield and reliability. ESD layouts that utilize the bond pad area increase the thermomechanical stress of the thin-films in the pad area and affect the assembly. Experimental data on products with different metal layout designs are compared to characterize the assembly yield and reliability performance. A computer finite element mechanical stress analysis is also conducted to quantify the interaction of pad design with the assembly. Experimental data and simulation showed a good correlation between the metal layout and the assembly yield and reliability. A degradation model is proposed with the support of detail failure analysis. A robust design solution is suggested to reduce the mechanical stress and improve the assembly yield and reliability