Array capacitor for decoupling multiple voltage rails

An array capacitor is provided. The array capacitor includes a plurality of ground planes inside a dielectric substrate, and a plurality of ground vias. The ground vias electrically connect the ground planes together. Further, the ground vias are connected to ground terminals of the array capacitor to enable electrical coupling between the ground planes and the ground terminals. The array capacitor further includes a plurality of power planes inside the dielectric substrate. The power planes and the ground planes are arranged alternatively inside the dielectric substrate. Each power plane comprises a plurality of power-plane-sections which are mutually electrically isolated. The array capacitor also includes a plurality of power vias which electrically connect the power planes together. Further, the power vias are connected to power terminals of the array capacitor to enable electrical coupling between the power planes and power terminals.