High frequency signal integrity in high-density assemblies

The demand for faster, portable and reliable electronic devices is increasing the pressure on the development of assembly techniques for signal integrity (SI). The advance of integrated circuits toward a large number of Input/Output (I/Os), a high number of operations and up to microwave communication frequencies, is behind the drive for the search for new packaging solutions. The materials and assembly techniques have an important impact on the propagation of high speed signals. Signal integrity issues emerge due to the electrical losses of materials, reflections from impedance discontinuities in the signal path and fast transitions of the signals. For these reasons, signal integrity in lead-free connections of WLCSP, flip chip (FC) and Integrated Module Board (IMB) assemblies were investigated up to 50 GHz. The increase of conductor loss resulting from the presence of thick oxide layers on the surface of solder bumps of hot running components was experimentally studied for the first time. Utilizing theoretical calculations, a design rule was developed to account for the 40 % increase in losses due to the presence of oxide layers at high frequencies. The research into the influence of solder microstructure on signal quality showed that it did not negatively affect the wave propagation. Experimental results proved that the presence of underfills and high density routing on printed wiring boards (PWBs) under the WLCSP components, detuned the components and the connections. The effects of three different underfills on signal propagation were studied. It was proven that the changes resulting from the rheology and parameters of curing process influence the losses and reflections of circuits. The analysis of microwave performances of flip chip (FC) and Integrated Module Board (IMB) assembly techniques demonstrated that they are well suited to Radio frequency (RF) and high speed applications. Comparison showed that IMB performed better as the wave encountered smaller discontinuities and had an optimized propagation path. Full wave simulations of IMB assemblies were performed considering finite ground coplanar waveguide (FGCPW), microstrip and stripline connections with stack-ups that included high dielectric constant materials and four connection possibilities. The research was carried out in the domains of both frequency and time to rigorously determine the sources of signal reflections. The results emphasized that in the design for match impedance and optimal current return path, discontinuities and reference planes had significant impact on signal integrity

Maximum crosstalk estimation and modeling of electromagnetic radiation from PCB/high-density connector interfaces

This dissertation explores two topics pertinent to electromagnetic compatibility research: maximum crosstalk estimation in weakly coupled transmission lines and modeling of electromagnetic radiation resulting from printed circuit board/high-density connector interfaces. Despite an ample supply of literature devoted to the study of crosstalk, little research has been performed to formulate maximum crosstalk estimates when signal lines are electrically long. Paper one illustrates a new maximum crosstalk estimate that is based on a mathematically rigorous, integral formulation, where the transmission lines can be lossy and in an inhomogeneous media. Paper two provides a thorough comparison and analysis of the newly derived maximum crosstalk estimates with an estimate derived by another author. In paper two the newly derived estimates in paper one are shown to be more robust because they can estimate the maximum crosstalk with fewer and less restrictive assumptions. One current industry challenge is the lack of robust printed circuit board connector models and methods to quantify radiation from these connectors. To address this challenge, a method is presented in paper three to quantify electromagnetic radiation using network parameters and power conservation, assuming the only losses at a printed circuit board/connector interface are due to radiation. Some of the radiating structures are identified and the radiation physics explored for the studied connector in paper three. Paper four expands upon the radiation modeling concepts in paper three by extending radiation characterization when material losses and multiple signals may be present at the printed circuit board/connector interface. The resulting radiated power characterization method enables robust deterministic and statistical analyses of the radiated power from printed circuit board connectors. Paper five shows the development of a statistical radiated power estimate based on the radiation characterization method presented in paper four. Maximum radiated power estimates are shown using the Markov and Chebyshev inequalities to predict a radiated power limit. A few maximum radiated power limits are proposed that depend on the amount of known information about the radiation characteristics of a printed circuit board connector --Abstract, page iv

Avionics system design for high energy fields: A guide for the designer and airworthiness specialist

Because of the significant differences in transient susceptibility, the use of digital electronics in flight critical systems, and the reduced shielding effects of composite materials, there is a definite need to define pracitices which will minimize electromagnetic susceptibility, to investigate the operational environment, and to develop appropriate testing methods for flight critical systems. The design practices which will lead to reduced electromagnetic susceptibility of avionics systems in high energy fields is described. The levels of emission that can be anticipated from generic digital devices. It is assumed that as data processing equipment becomes an ever larger part of the avionics package, the construction methods of the data processing industry will increasingly carry over into aircraft. In Appendix 1 tentative revisions to RTCA DO-160B, Environmental Conditions and Test Procedures for Airborne Equipment, are presented. These revisions are intended to safeguard flight critical systems from the effects of high energy electromagnetic fields. A very extensive and useful bibliography on both electromagnetic compatibility and avionics issues is included

A complete design path for the layout of flexible macros

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Design for Electromagnetic Compatibility--In a Nutshell

This open access book provides practicing electrical engineers and students a practical – and mathematically sound – introduction to the topic of electromagnetic compatibility (EMC). The author enables readers to understand better how to overcome commonly failed EMC tests for radiated emission, radiated immunity, and electrostatic discharge (ESD), while providing concrete EMC design guidelines. The book also presents an overview of EMC standards and regulations and how to test for a global market access

Design for Electromagnetic Compatibility--In a Nutshell

This open access book provides practicing electrical engineers and students a practical – and mathematically sound – introduction to the topic of electromagnetic compatibility (EMC). The author enables readers to understand better how to overcome commonly failed EMC tests for radiated emission, radiated immunity, and electrostatic discharge (ESD), while providing concrete EMC design guidelines. The book also presents an overview of EMC standards and regulations and how to test for a global market access

Modeling and estimation of crosstalk across a channel with multiple, non-parallel coupling and crossings of multiple aggressors in practical PCBS

In Section 1, the focus is on alleviating the modeling challenges by breaking the overall geometry into small, unique sections and using either a Full-Wave or fast equivalent per-unit-length (Eq. PUL) resistance, inductance, conductance, capacitance (RLGC) method or a partial element equivalent circuit (PEEC) for the broadside coupled traces that cross at an angle. The simulation challenge is resolved by seamlessly integrating the models into a statistical simulation tool that is able to quantify the eye opening at BERs that would help electrical designers in locating crosstalk sensitive regions in the high speed backplane channel designs. Section 2 investigates the FEXT crosstalk impact on eye opening at a specified bit error rate (BER) at different signal speeds for broadside and edge side differential coupled traces in inhomogeneous media and compared the results against homogeneous media models. A set of design guidelines regarding the material, coupled length and stackup parameter selection is formulated for designers based on the signaling speeds. The major objective of the study in Section 3 is to determine quantitatively the effect of crosstalk due to periodic broadside coupled routing. Another objective is to help designers figure out the “dos” and “don’ts” of broadside coupled routing for higher signaling rates. A new methodology is proposed in Section 4 to generate BER contours that capture the Tx driver jitter and ISI through the channel accurately using unique waveforms created from truth table bit combinations. It utilizes 2N short N bit patterns as waveforms and jitter correlation from current bit pattern into adjacent bit patterns to get equivalent transient simulation of a very large bit pattern. --Abstract, page iii

VLSI Design

This book provides some recent advances in design nanometer VLSI chips. The selected topics try to present some open problems and challenges with important topics ranging from design tools, new post-silicon devices, GPU-based parallel computing, emerging 3D integration, and antenna design. The book consists of two parts, with chapters such as: VLSI design for multi-sensor smart systems on a chip, Three-dimensional integrated circuits design for thousand-core processors, Parallel symbolic analysis of large analog circuits on GPU platforms, Algorithms for CAD tools VLSI design, A multilevel memetic algorithm for large SAT-encoded problems, etc

Design and Development of a Multi-Purpose Input Output Controller Board for the SPES Control System

This PhD work has been carried out at the Legnaro National Laboratories (LNL), one of the four national labs of the National Institute for Nuclear Physics (INFN). The mission of LNL is to perform research in the field of nuclear physics and nuclear astrophysics together with emerging technologies. Technological research and innovation are the key to promote excellence in science, to excite competitive industries and to establish a better society. The research activities concerning electronics and computer science are an essential base to develop the control system of the Selective Production of Exotic Species (SPES) project. Nowadays, SPES is the most important project commissioned at LNL and represents the future of the Lab. It is a second generation Isotope Separation On-Line (ISOL) radioactive ion beam facility intended for fundamental nuclear physics research as well as experimental applications in different fields of science, such as nuclear medicine; radio-pharmaceutical production for therapy and diagnostic. The design of the SPES control system demands innovative technologies to embed the control of several appliances with different requirements and performing different tasks spanning from data sharing and visualization, data acquisition and storage, networking, security and surveillance operations, beam transport and diagnostic. The real time applications and fast peripherals control commonly found in the distributed control network of particle accelerators are accompanied by the challenge of developing custom embedded systems. In this context, the proposed PhD work describes the design and development of a multi-purpose Input Output Controller (IOC) board capable of embedding the control of typical accelerator instrumentation involved in the automatic beam transport system foreseen for the SPES project. The idea behind this work is to extend the control reach to the single device level without losing in modularity and standardization. The outcome of the research work is a general purpose embedded computer that will be the base for standardizing the hardware layer of the frontend computers in the SPES distributed control system. The IOC board is a Computer-on-Module (COM) carrier board designed to host any COM Express type 6 module and is equipped with a Field Programmable Gate Array (FPGA) and user application specific I/O connection solutions not found in a desktop pc. All the generic pc functionalities are readily available in off-the-shelf modules and the result is a custom motherboard that bridges the gap between custom developments and commercial personal computers. The end user can deal with a general-purpose pc with a high level of hardware abstraction besides being able to exploit the on-board FPGA potentialities in terms of fast peripherals control and real time digital data processing. This document opens with an introductory chapter about the SPES project and its control system architecture and technology before to describe the IOC board design, prototyping, and characterization. The thesis ends describing the installation in the field of the IOC board which is the core of the new diagnostics data readout and signal processing system. The results of the tests performed under real beam conditions prove that the new hardware extends the current sensitivity to the pA range, addressing the SPES requirements, and prove that the IOC board is a reliable solution to standardize the control of several appliances in the SPES accelerators complex where it will be embedded into physical equipment, or in their proximity, and will control and monitor their operation replacing the legacy VME technology. The installation in the field of the IOC board represents a great personal reward and crowns these years of busy time during which I turned what was just an idea in 2014, into a working embedded computer today

Design of high frequency operating mechatronic systems : tools and methods of characterization of electromagnetic couplings between electromechanic converters and power electronics converters

From the more electrically operated aircraft, to the hybridization of motor vehicles, all the way to electromechanic cardiac implants, compactness has become the holy grail of modern embedded electrical engineering. Indeed, the power-to-weight ratio demands for electromechanical systems has greatly increased. To meet these high integration needs, power electronic converters find a vector of development by increasing their temperature and operating frequencies but also by reducing the switching time of power switches, thus enabling them to reduce their power losses and thereby reducing their cooling requirements. Electric motors and generators operate with various innovative topologies that meet integration, robustness and reliability needs. Motor windings, particularly, are the first motor components on the battle front. It is at the heart of the winding that occur the exchanges between motor and converter. In terms of electromagnetic compatibility (EMC) for embedded systems, the increased frequency and transient stresses in the form of current and voltage edges from the power electronic assemblies are considered steep challenges. The work presented herein is the result of a close cooperation between the company Novatem and the laboratory Génie de Production of ENIT de Tarbes, through CIFRE funding, in combination with the Labceem platform of IUT of Tarbes. Its aim is to develop predictive models that will serve to determine the consequences of such integration constraints in power mechatronic systems that are in the early stages of design. Conducted disturbances whose HF source is located at the inverter power switches are shaped by the impedances characterizing the coupling path of which the electrical machine is an integral part. This work proposes to develop methods and tools to support the predictive study of electromagnetic compatibility (EMC) of mechatronic assemblies, by attempting to cover a modeling frequency range that goes from 0 to 300 MHz’s. In the first chapter of this work, a literature review is detailed for the definition of the context and boundaries of the study. A second chapter focuses on the analytical modeling of concentrated windings in electric motors. The analytical models that are established allow determination of circuit networks settings to perform time- and frequency- domain simulations. Unlike the widespread behavioral models of electrical machine in the literature, the models that are synthesized here take into account the physical parameters of the coils. The user of such models is offered the opportunity to account for the different winding architectures, by changing core parameters such as geometry, insulation materials or permeability. A third chapter describes the establishment of a rational method for extraction of functional and parasitic parameters in multilayer Power PCBs. This method being of a generic and predictive logic aims to account for physical parameters. Finally, in the last chapter, the previously established tools and methods are applied to the study of a real electric vehicle drive system developed by the company Novatem. The physical and predictive value of these tools allows for execution of virtual experimentations on the motorconverter assembly without the need for prototypes. This chapter illustrates the value of a physical approach to modeling the electromagnetic compatibility of mechatronic systems