3D PCB architecture for next generation high speed interconnections

Abstract

Purpose

To review the challenges confronting the electronics interconnection industry as it transitions into the gigahertz frequency range and to describe novel prospective solutions designed to circumvent the problems by means of alternative interconnection architectures while remaining within the confines of the existing manufacturing infrastructure.

Design/methodology/approach

The paper has been written in a manner so as to provide first a brief review of the history of interconnections as background reference, providing access and understanding to a broader readership of the significance of the area of investigation. From there, the paper describes the problems facing electronic circuit manufactures relative to the serious matter of assuring signal integrity of high speed interconnections. It then goes on to describe a general class of prospective solutions, which can be implemented through simple architectural changes in design and manufacture. Finally, the paper describes a prototype system which was fabricated using the concepts and the first‐order findings are provided.

Findings

From operation of the prototype system, it was found that the concepts, relative to PCB architectural changes prescribed in the paper are capable of delivering performance levels beyond what is accepted when using traditional interconnection modalities. The 10 Gbps backplane prototype has proved capable of sending a 100 mV peak‐to‐peak signal a distance of 75 cm through a two wire single differential pair which pass through two industry standard connectors. The signal generated has a ∼65 percent margin indicating it could go much further and determining the limits an object of future study. The modulation is standard NRZ. With only two wires there was no cross talk in the system, however, the next stage of investigation will consist of a multi‐device assembly to see what cross talk effect there might be, if any.

Originality/value

The chief value of the paper resides in its disclosure of novel approaches to electronic interconnection involving simple changes in circuit architectural structures which extend the signal performance limits of copper interconnections, well beyond present consensus expectations of industry. Moreover, the paper provides first experimental results of the technology in actual operation as proof of concept.

Citation

Fjelstad, J., Grundy, K. and Yasumura, G. (2005), "3D PCB architecture for next generation high speed interconnections", Circuit World, Vol. 31 No. 4, pp. 25-33. https://doi.org/10.1108/03056120510603116