High-speed characteristics of multilayer ceramic packages and test fixtures

The high-speed electrical characteristics of a typical multilayer ceramic (MLC) package are described and a model presented. The tests were conducted in a realistic environment which closely models the surface mount environment for which the packages are intended. These MLC packages incorporate many of the same refinements used at the circuit-board level to improve high-speed performance, namely use of controlled impedance, 50 Omega , signal lines, multiple ground connections, and on-package power and ground planes. Using pulse reflection and transmission measurements as a diagnostic tool, it is shown how to develop a full SPICE model for a high-speed MLC package in a systems environment. A dominant electrical feature of the configuration is the ground plane discontinuity at the package-to-circuit board interface. This feature is prominent in the observed high-speed pulse response of the system.<>