An efficient pre-assignment routing algorithm for flip-chip designs

The flip-chip package is introduced for modern IC designs with higher integration density and larger I/O counts. In this paper, we consider the pre-assignment flip-chip routing problem with predefined connections between driver pads and bump pads. This problem has been shown to be much more difficult than the freeassignment one, but is more popular in real-world designs because the connections between driver pads and bump pads are typically pre-determined by IC or packaging designers. Based on the concept of routing sequence exchange, we propose a very efficient global routing algorithm by computing the weighted longest common subsequence (WLCS) and the maximum planar subset of chords (MPSC) for pre-assignment flip-chips. We observe that the existing work over constrains the capacity of a routing tile, which might miss some critical solution space with a better routing solution (e.g., smaller wirelength), and provide a remedy for this insufficiency to identify a better solution in a m...

• Type: Journal
• Year: 2009
• Where: ICCAD
• Authors: Po-Wei Lee, Chung-Wei Lin, Yao-Wen Chang, Chin-Fang Shen, Wei-Chih Tseng
• Keywords: Driver Pads, Hardware, ICCAD 2009, Pre-assignment Flip-chips, Routing