Low inductance grid array capacitor

Abstract

An improved low inductance termination scheme is disclosed for grid array capacitors. The enhanced termination scheme provides for shorter termination length and leaves the sides of a capacitive element free from any structure. The area typically taken up by solder lands is reduced, facilitating much closer chip spacing on a circuit board. The arrangement generally includes interleaved dielectric and electrode layers in an interdigitated configuration. Vias are drilled through tabs extending from selected of the electrode layers, and then filled with suitable conductive material. Solder balls may be applied directly to this conductive material, providing a ball grid array (BGA) packaged chip ready to mount on an IC and reflow. Composition of such solder balls is easily varied to comply with specific firing conditions. Such capacitor chips are also compatible with land grid array (LGA) packaging techniques. The subject interdigitated electrode design may be utilized to form a single multilayer capacitor or multiple discrete capacitors. Such a capacitor array may be formed by retaining the external configuration and internally subdividing the electrodes. The resulting low cost, low inductance capacitor is ideal for many high frequency applications requiring decoupling capacitors.