This paper reviews the fundamentals and latest progress of modeling, analysis, and design technologies for signal integrity and electromagnetic compatibility on PCB and package in the past decades. Most results in this field are based on the very rich and highly educational literature produced by Prof. C. Paul in his long scientific career. The inclusion of parameters variability effects is also considered, and it is demonstrated how statistical simulations can become affordable by means of recently-introduced stochastic methods. Finally, the necessity of practical training of designers is mentioned, and an experience relying on realistic PCB demonstrators is illustrated.

Overview of Signal Integrity and EMC Design Technologies on PCB: Fundamentals and Latest Progress

The ever-increasing demands of digital computing and wireless communication have been driving the semiconductor technology to change with each passing day. Modern electronic systems integrate more complex components and devices, which results in a very complex electromagnetic (EM) field environment. EM compatibility has become one of the major issues in ICs redesign, mainly due to the lack of efficient and accurate simulation tools and expertise on noise reduction and immunity improvement. This paper reviews the state of the arts of IC, electronic package, and printed circuit board simulation and modeling technologies. It summarizes the modeling technologies for both available structures [multilayered power-ground planes and macromodeling of interconnect (INC)] and novel structures (nano-INCs and 3-D ICs based on through-silicon via technology). It also illustrates the trends of simulation and modeling technologies in EM compatibility, signal integrity, and power integrity.

Progress Review of Electromagnetic Compatibility Analysis Technologies for Packages, Printed Circuit Boards, and Novel Interconnects

Analytical models for vias and traces are presented for simulation of multilayer interconnects at the package and printed circuit board levels. Vias are modeled using an analytical formulation for the parallel-plate impedance and capacitive elements, whereas the trace-via transitions are described by modal decomposition. It is shown that the models can be applied to efficiently simulate a wide range of structures. Different scenarios are analyzed including thru-hole and buried vias, power vias, and coupled traces routed into different layers. By virtue of the modal decomposition, the proposed method is general enough to handle structures with mixed reference planes. For the first time, these models have been validated against full-wave methods and measurements up to 40 GHz. An improvement on the computation speed of at least two orders of magnitude has been observed with respect to full-wave simulations.

Physics-Based Via and Trace Models for Efficient Link Simulation on Multilayer Structures Up to 40 GHz

After providing an overview of the state-of-the-art in power distribution design and modeling, this paper focuses on return path discontinuities (RPDs) for I/O signaling. After briefly describing their importance in the context of simultaneous switching noise, a specific case of RPD based on via discontinuities is discussed in detail in the context of both the frequency- and time-domain waveforms using a test vehicle. The modeling of RPD in practical packages and printed circuit boards is addressed along with substrate coupling due to nonideal reference planes. Finally, a high-impedance power distribution scheme for I/O signaling is presented that can potentially solve a number of RPD-related problems, followed by future challenges.

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Designing and Modeling for Power Integrity

In this paper, a stripline model is presented for coupled signal lines routed between a power and a ground plane based on multiconductor transmission line (MTL) theory. Through a suitable diagonalization of the MTL equations for striplines, the transverse electromagnetic (TEM) parallel-plate mode is decoupled from the stripline mode. In this way, stripline models that are obtained assuming ideal planes at ground potential can be extended to take into account the nonideal behavior of the planes. The presented model is applied to represent mode conversion due to vias, holes in the reference planes, and terminations of the stripline. Influence of inhomogeneous media is discussed

Modeling of striplines between a power and a ground plane

A multiconductor transmission line model for stripline structures is derived, which can represent the interaction between the signal lines and the power planes. The advantages of the proposed model over an existing alternative model are discussed.

Modeling of non-ideal planes in stripline structures

Parasitics associated with the current return path discontinuity (RPD) are among the major factors affecting the signal integrity (SI) and electromagnetic compatibility (EMC) behavior of digital circuits with fast switching drivers. Vias that connect signal lines referenced to different planes cause RPD, such that the signal return current has to jump between the planes to close the current loop. In addition to the plane-vias (for planes at the same voltage level) and decoupling capacitors (for planes at different voltage levels) between the planes, the inter-plane capacitance represents a possible return path, which has to be modeled as a distributed element for plane dimensions comparable to a wavelength.

A.E. Engin

Papers

Modeling of striplines between a power and a ground plane

Modeling of non-ideal planes in stripline structures

Modeling and analysis of the return path discontinuity caused by vias using the 3-conductor model