Millimeter-Wave Propagation within a Computer Chip Package

TL;DR

This paper models wave propagation in a realistic chip package to understand mmWave wireless channels for chip-scale communication, revealing potential for low-attenuation wireless links within chips.

Contribution

It provides a detailed modeling approach for chip packages and identifies optimal configurations for 60 GHz wireless communication inside chips.

Findings

Achieved chip-wide attenuation below 32.6 dB at 60 GHz

Identified optimal parameters for wave propagation in chip packages

Discussed applicability to higher frequency bands and other environments

Abstract

Wireless Network-on-Chip (WNoC) appears as a promising alternative to conventional interconnect fabrics for chip-scale communications. The WNoC paradigm has been extensively analyzed from the physical, network and architecture perspectives assuming mmWave band operation. However, there has not been a comprehensive study at this band for realistic chip packages and, thus, the characteristics of such wireless channel remain not fully understood. This work addresses this issue by accurately modeling a flip-chip package and investigating the wave propagation inside it. Through parametric studies, a locally optimal configuration for 60 GHz WNoC is obtained, showing that chip-wide attenuation below 32.6 dB could be achieved with standard processes. Finally, the applicability of the methodology is discussed for higher bands and other integrated environments such as a Software-Defined Metamaterial (SDM).