Shuttle mask floorplanning with modified alpha-restricted grid

ABSTRACT

Multi Project Wafer (MPW) is an efficient method to share the mask cost among projects of different enterprisers for prototyping and low-volume manufacturing of IC designs. Designs from multiple customers can be put on one single mask substrate to produce MPW. Unlike traditional floorplanning, we need to consider the side-to-side wafer dicing constraint of the diamond sawing technology and different technology processes used in different projects for this problem. In our work, we use a branch and bound algorithm to solve this problem with a grid packing approach. We defined a special type of grid, called the modified α-restricted grid, to reduce the size of the searching solution space. Unlike many previous works, we consider non-zero margin width (but copies of the same design will have the same margin width), different technology processes of the projects, multiple copies of the same design on a mask, etc. In each searching step, our algorithm generates a grid and try to pack the dies into the grid by a Two Phase Packing(TPP) heuristic. We consider circular wafers and the objective is to minimize the total production cost. The experimental results are very promising and our approach can out-perform the most up-to-date works on this problem.

REFERENCES

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INDEX TERMS

Primary Classification:
  B. Hardware
  B.7 INTEGRATED CIRCUITS
      B.7.2 Design Aids
          Subjects: Placement and routing

Additional Classification:
  J. Computer Applications
  J.6 COMPUTER-AIDED ENGINEERING
      Subjects: Computer-aided design (CAD)

General Terms:
Algorithms, Design

Keywords:
multi-project wafers, reticle design