An empirical study on the robust design of a semiconductor-bumping process

Based on empirical data collection, computer simulation, statistical methods, and optimization techniques, this paper presents a study on optimizing the parameters of the solder bumping process in semiconductor fabrication (FAB). The research first collects a set of experimental data from the production site at the FAB. In this research, the experimental data of interest include bump height (BH) and bump shear (BS). Then, the researchers use the regression method for the experimental data on controllable factors to build an empirical model for problem analysis. The resulting empirical model is used to generate a set of experimental data to determine the critical controllable factors by design of experiments (DOE). Based on these empirical models, the optimum parameter values of controllable factors are found by optimization techniques such as mathematical programming. Because there are two quality characteristics, of interest in this research, a sensitivity analysis is performed during the problem analysis. As a result, a robust parameter design for quality improvement can be achieved for process design and planning.