Hierarchical environmental impact evaluation of a process in printed circuit board manufacturing

Considering the growing concerns and importance of environmental issues, manufacturing industrialists, in particular those in electronics manufacturing, are seeking methods to evaluate the environmental performance of their manufacturing processes. These environmental evaluation tools should be capable of performing detailed analysis on the environmental performance of each individual process unit, identifying the environmental improvement opportunity and providing adequate decision support to environmental engineers for process modification and operational change. This paper modifies and improves the environmental impact evaluation model already developed and provides directions for decision-making at various stages of the analysis. The decision algorithm in this revised model adopts a hierarchical environmental impact evaluation approach and uses five impact categories related to ecological health and seven categories related to human health to form the base of an evaluation hierarchy. The algorithm, with its evaluation results presented in all levels of the hierarchy, is proposed as a means of tracking, controlling and improving the environmental performance of a process. A printed circuit board case study shows the effectiveness and applicability of the algorithm. The results indicate that the electroless copper process has a higher impact on ecological health than on human health, and that the phosphoric acid in the waste components is the identified major source of the impact on ecological health.