MCM-D for high speed digital applications-electrical modelling and performance evaluation

When a new interconnection technology is developed, it is of interest to accurately characterise its electrical features and evaluate its possible application areas and boundary limits. Accurate design models can then be extracted and used for a correct design and implementation of electronic systems. This paper describes a case study used to characterise a 5-layer thin-film Multi-Chip Module (MCM-D) technology developed for high speed digital applications. The high frequency characterisation of the substrate has been combined with the SPICE models of the I/O buffers of a CMOS technology to accurately analyse the signal propagation with a network simulation tool. A test chip and MCM module have been developed to evaluate how the maximum system frequency is influenced by different quantities such as line length, type of driver, or noise using a new validation methodology. Experimental results, showing a good match with simulations, demonstrate the effectiveness of this approach. It is also shown how it is possible to take advantage of some apparently limiting features of thin-film MCMs to actually improve the system performance.