Interposer with embedded circuitry and method for using the same to

Abstract

An interposer for assembly between an integrated circuit and a circuit panel includes an upper insulation layer and a plurality of upper contact pads arranged in a desired pattern in the upper insulation layer. A plurality of micro-devices are formed between the upper insulation layer and a bottom insulation layer having a plurality of lower contact pads arranged in a desired pattern. The upper and the lower contact pads are selectively and electrically interconnected via the micro-devices. The upper and the lower contact pads are overlaid with solder balls to provide the required electrical connection and mechanical coupling between the interposer, the integrated circuit, and the circuit panel. The interposer is made by forming an array of upper contact pads on a substrate; depositing an upper layer of encapsulant material on the substrate; planarizing the substrate and exposing the array of upper contact pads; forming a micro-device; forming an array of lower contact pads; forming a bottom insulation layer; and exposing at least some of the lower contact pads. According to another embodiment, the interposer includes a plurality of electrically conductive terminals that extend outwardly from the lower contact pads for establishing an electrical connection and a mechanical spring action between the integrated circuit and the interposer, in order to absorb excess contraction or expansion.