Vector-based Peak Current Analysis during Wafer Test of Flip-chip Designs

Power consumption has not only become a critical concern in VLSI design phase, but also in test phase. This work focuses on power during test, covering two major research topics: test power analysis and test power reduction. For the analysis part, we firstly demonstrate our basic switching and weighted switching activity analysis in various test phases, pattern set, benchmarks. Then, we propose a layout-aware power analysis flow, with the capability of performing IR-drop analysis, peak current analysis. This flow is integrated in test pattern simulation and is able to monitor power and current behavior across the entire test session, without introducing much CPU run time overhead. It is an universal power analysis methodology that can be applied to various digital designs, technologies, as well as handling low power design features. For the test power reduction part, we proposes a power sensitive scan identification flow to help identify and gate scan cells so as to reduce shift power without introducing much power overhead in capture mode