Fig. 1 shows a schematic of an EAC inside a microprocessor package. The EAC is placed inside a cut-out within the HDI substrate core and the surrounding space is filled with a plug-ging material which is cured before the substra tebuild-up(BU). Alternate EAC electrodesare connected to power and groundso that the capacitance is in parallel to the power supply. Typical EAC length and width is of the order of several mm, while the thickness is of the order of substrate core, i.e., in the range of a mm for ultrahigh performance packages.