Multi-objective production scheduling of probe process in semiconductor manufacturing

Semiconductor products are manufactured through the process of wafer fabrication, probe or electrical die sorting, assembly and final test. In particular, in this study we deal with the wafer probe process which requires several types of equipment with different capacities. As a connecting procedure of the fabrication and the assembly, the probe process may determine the capacity of whole semiconductor manufacturing. The throughput needs to be maximized as for most manufacturing lines. Because of unexpected machine failure and planned preventive maintenance, the utilization of machines has to be kept at a certain range for stabilizing the process. Hence, the production progress for each device and the utilization of machines are objectives to be maximized simultaneously, while both tend to work in opposite directions because of changeover time loss. Heuristic algorithms are developed and computationally tested. LP-based heuristic gives satisfactory results, especially for the manufacturing line with high diversity in types of machine and device.