Integrated Capacity Planning System for IC Backend Factory
Integrated Circuit (IC) manufacturing consists of four major phases - wafer fabrication, wafer probe, IC packaging, and final test. Wafer fabrication and wafer probe belong to front-end process, while IC packaging and final test belong to backend process. In this research, integrated capacity planning system (ICPS) is proposed for IC backend manufacturing by taking into account the capacity and capability of resources. This study develops integrated infinite capacity planning integrating the capacity planning of both IC packaging and final test processes to minimize the standard deviations of machine utilization and kit utilization as well as the total extra capacity requirement (as a percentage) exceeding the capacity limit of machine and kit. ICPS applies the concept of workload leveling and infinite capacity planning on dual resources. ICPS consists of five modules: Work-In-Process (WIP) Pulling Module, Lot Release Module, Resource Selection Module, Workload Accumulation Module, and Workload Balance Module. WIP-Pulling Module pulls WIP from the end of the process route to meet the master production schedule (MPS). If WIP cannot meet the MPS requirement, Lot Release Module is executed. ICPS will use Resource Selection Module to accumulate the required resource capacity along its routine at different time buckets. Workload Accumulation Module simultaneously accumulates the workload of the major resources. Workload Balance Module levels the loading of resources by adjusting the lot’s start time using these resources. ICPS is developed in Microsoft Visual Basic and industrial data are used to test its performance. The results show that ICPS is effective and efficient to balance the workload of resources for IC backend factories including packaging and final test.
Daizhong Su, Qingbin Zhang and Shifan Zhu
J. C. Chen et al., "Integrated Capacity Planning System for IC Backend Factory", Key Engineering Materials, Vol. 450, pp. 369-372, 2011