Capacity planning with reconfigurable kits in semiconductor test manufacturing

To test an integrated circuit (IC) product, both a tester and qualified kits are simultaneously needed. One kit usually consists of six or seven components and is somewhat like a fixture. A remarkable amount of investment will be saved if one allows kit reconfigurations and purchases individual components instead of using entire kits. Unfortunately, this approach of the reconfigurable kit also increases exponentially the complexity of kit management and thus capacity planning due to intricate (product, tester, kit, component) qualification relationships. The paper describes the Automated Capacity Allocation System (ACAS) developed at Intel Shanghai for generating an optimal capacity and kit-allocation plan for a 9-week horizon. It performs optimization at the component level using Mixed-Integer Programming (MIP) technology. High Buffer Formulation and Tight Workload Formulation are introduced to determine the number of kits needed to guarantee a feasible capacity plan. Detailed analyses of parameter setting, objective prioritizing and formulation comparison were also conducted. With the implementation of the ACAS at Intel, we have already realized millions of dollars in savings from kit purchasing and about 90% man-hour savings in the capacity planning.