Evaluation of sweep resistance of Q Auto-Loop and Square-Loop bonds for semiconductor packaging technology

Wire sweep is a main concern in the semiconductor packaging industry. The wire bonding technology, providing versatile and reliable chip-connection method, is usually adopted for MCM and 3-D package. However, there is no (standard) approach found to determine the ability of sweep resistance for a certain bond profile in the literature. In a parallel study, the concept of sweep stiffness is defined from the slope of the load–transverse displacement curves to express sweep resistance of wire bond. In this paper, two frequently used bond profiles, the Q Auto-Loop and Square-Loop bonds, were investigated experimentally to assess the effect of bond span and height on sweep resistance. Results show that the Q Auto-Loop bond has a higher sweep resistance than the Square-Loop bond, for all wire diameters. Moreover, numerical results and proposed model predictions were performed to compare with sweep stiffness experiments. Underestimated predictions indicate the importance of bond profile characteristics to sweep stiffness values, which must be included in numerical analysis.