Modeling of performance-related design trade-offs in multi-chip assemblies

The authors discuss the need for development of global performance measures for multi-chip microelectronic assemblies and systems. In particular, electrical performance measures of memory assemblies and their dependence on design parameters were studied. Models of pertinent components of electronic systems, such as off-chip drivers and receivers, and chip-to-chip signal transmission lines were used to evaluate essential properties of memory modules. The read access time was selected as a measure of performance of those modules. Using simple modeling this measure is related to basic parameters such as conductor geometry, substrate material thickness and permittivity, I/O pitch in chip carriers and chip access time. The specific memory module considered shows strong dependence of performance measure on materials used in its construction. The relationships between systems performance, materials properties, and geometry are described by analytic approximations; however, more accurate modeling will use look-up tables and specialized computer programs. Development of suitable computer support for system design based on developed models of performance is discussed