Discontinuity cancellation to boost package bandwidth up to material's limitations - 40 Gbps package design using wire-bonded PBGA

Abstract

We present a 40-Gbps packaging solution that uses low-cost wire-bonded plastic ball grid array (WB-PBGA) technology. Since such a high speed is beyond the reach of conventional package design, new design methodology is proposed. The 3-D structures of bonding wires, vias and solder balls are to be optimized for discontinuity cancellation. Two versions of four-layer WB-PBGA packages were designed, one according to the proposed methodology and the other conventionally. The remarkably enhanced performance of the proposed design is verified with full-wave simulation, passive bandwidth measurement, time domain reflectometry (TDR) and 40-Gbps eye measurement.