Anisotropic conductive film (ACF) flip-chip interconnect in over GHz RF clock distribution system

Conductive polymer adhesives have been proposed as lead-free materials for flip-chip interconnection. The Semiconductor Industry Association (SIA) roadmap forecasts off-chip clock frequencies over 1 GHz by 2005. In GHz clock distribution issues such as clock skew, power, and timing jitter are becoming more crucial and strongly impact the operating speed of the digital processors. Interconnection technology, particularly at board-level and package-level, is lagging the VLSI technology. To achieve high performance in digital and microwave devices, an accurate microwave frequency interconnection model is required. This paper describes a model extraction methodology based on S-parameter measurement, microwave network analysis, and parameter optimization using genetic algorithm. Using the microwave frequency interconnection model, an RF clock distribution system for low power multiprocessor digital system was also simulated using HP Advanced Design System (ADS).