Board Design Research Articles

System I/O Optimization with SoC, SiP, PCB Co-Design

Abstract The increasing complexity of system on chips (SoCs) combined with a new generation of designs that combine multiple chips in a single package is creating new challenges in the design of packages, printed circuit boards (PCBs) and integrated circuits (ICs). The process typically involves three independent design processes – chip, package and PCB – carried out with point tools whose interface requires time-consuming manual processes that are error-prone and limit the potential for reuse. This challenge is being addressed by a new integrated 3D chip/package/board co-design environment that makes it possible to holistically optimize the package, board and IC design to a greater degree than was possible in the past by considering the system-level impact of each design decision. The new co-design approach enables designers to optimize routability via pin assignment and I/O placement to achieve minimum layer counts between chip, package and board. The end result is higher performance.

The Independent Board as Shield

The fiduciary duty of loyalty bars CEOs and other executives from managing companies for personal gain. In the modern public corporation, this restriction is reinforced by a pair of institutions: the independent board of directors and the business judgment rule. In isolation, each structure arguably promotes manager fidelity to shareholder interests—but together, they enable manager prioritization. This marks a particularly striking turn for the independent board. Its origin story and raison d’etre lie in protecting shareholders from opportunism by managers, but it functions as a shield for managers instead. Numerous defects in the design and practice of the independent board inhibit its ability to curb managerial excess. Nowhere is this more evident than in the context of transactions that enrich the CEO. When executive compensation and similar matters are approved by independent directors, they take on a new quality: they become insulated by the business judgment rule. This rule is commonly justified as giving legal effect to the comparative advantage of businesspeople in their domain—in determining the price of a product, for example—and it immunizes such decisions from court challenge. But independent directors can opt to extend the rule’s protection beyond this narrow class of duty of care cases to domains that squarely implicate the duty of loyalty. The result is a shield for conflicts of interest that defeats the major objective of the independent board and important goals of corporate law more generally. This Article proposes to eliminate the independent board’s paradoxical shield quality by ending business judgment protection for claims implicating the duty of loyalty. Judges would apply the familiar entire fairness standard instead. The clearest rationale for this reform comes from the logic of the rule itself: comparative advantage. Judges, not businesspeople, are best situated to adjudicate conflicts of interest. More broadly, the Article’s analysis suggests that the pro-shareholder reputation of the independent board is overstated and may have inadvertently fostered a sense of complacency around board power.

A 320x256 RGB LED Electronic Display Controlled via WiFi from Mobile Application

We present the design of a 320x256 RGB LED electronic display board intended to be used as a platform to present information of current and future events in schools or office buildings. The proposed design can display up to eight different images, which may include text and graphics. The rendering of these images is done periodically, with the duration of the period being controlled by the user. The images can be created from slides of a power point presentation or directly from stored photos. Loading of new images to the display board is done wirelessly via WiFi from an Android App running on a portable device such as a tablet or a smartphone. We present experimental results on a completed and fully operational prototype system, which includes the RGB LED display board together with the custom-built microcontroller board as well as the Android App. While the current use-application is as an informative message board in a school set-up, the proposed system can be used in any other indoor application. For outdoor usage, the system would require an additional weather-proof enclosure and fixtures.

Foreword: Special Section on Packaging and Interconnects: Cutting-Edge Solutions in Modeling, Design, and Characterization—Part I

In a world of digitally native citizens, processors and memory are common topics of conversation, no longer restricted to the engineering community. It is only natural. After all, one does not need to be an architect to appreciate the skyline of a modern metropolis. But behind this postcard image is a complex world of substrates and interconnects and buffers and packages. Smartphones and self-driving vehicles require advanced printed circuit board (PCB) and IC design. Advanced design relies on specialized computer-aided design (CAD) tools. CAD requires modeling and an entire field of mathematical know-how. But technology exists in the physical realm. Progress is also driven by the advance of materials and manufacturing techniques. Prototyping requires accurate measurements and precise characterization. Layers upon layers of knowledge and expertise make the intricate infrastructure of modern electronics possible. We seek to give an overview of the recent innovations across these layers. This special section is built from selected work initially presented at the SPI 2018, EPEPS 2018, and EDAPS 2018, conferences that are co-sponsored by the IEEE Electronics Packaging Society (EPS).

Power GaN FET boards thermal and electromagnetic optimization by FE modeling

This work deals with optimization of boards with commercial discrete power GaN FETs in applications where natural air convection is a strict constraint. In these cases, both thermal and electromagnetic behaviours are critical reliability issues for the board design, and they are modeled by Finite Element (FE) analysis, starting from literature description of the device structure, and measurements on a simple test circuit.For improved accuracy and more realistic modeling, verification and validation simulation steps are introduced, in order to evaluate the relevant error parameters for different FEM solutions.The results obtained demonstrate a good fitting with experimental and make it possible to improve board thermal characteristic. The electromagnetic simulations allow the evaluation, and possibly the reduction, of parasitic inductances for different layouts.Then, the proposed approach enables thermal and electromagnetic optimization of the layout design by simple FEM simulations, without any preliminary prototype, with time and cost saving.

Intrusion Detection in IoT based Smart Networks using Fuzzy Brain Storm Optimization Technique

The Internet of Things (IoT) is characterized as an approach where objects are outfitted with sensors, processors, and actuators which include design of hardware board and development, protocols, web APIs, and software systems, which combined to make an associated architecture of embedded systems. This connected environment enables technologies to get associated with different networks, platforms, and devices, making a web of communication which is reforming the manner in which we communicate with the world digitally. These connected embedded systems are changing behaviour and interactions with our environment, networks, and homes, and also with our own bodies in terms of smart devices. Security and privacy are the most significant consideration in the field of real-world communication and mainly on IoTs. With the evolution of IoT the network layer security in the IoT has drawn greater focus. The security vulnerabilities in the IoT system could make security risks based on any application. Therefore there is an essential requirement for IDS for the IoT based systems for avoiding security attacks based on security vulnerabilities. This paper proposed a fuzzy c-means clustering with brain storm optimization algorithm (FBSO) for IDS based on IoT system. The NSL-KDD dataset is utilized to evaluate and simulate the proposed algorithm. The results demonstrate that the proposed technique efficiently recognize intrusion attacks and decrease the network difficulties.

Surface design of wood-based board to imitate wood texture using 3D printing technology

Wood texture has a beautiful appearance and tactile feeling, making it very appropriate for furniture applications. However, the fabrication of a wood texture on wood-based boards can be inefficient and less green when performed using conventional methods. In this study, a wood-like surface on a wood-based board was designed to imitate a wood texture using 3D printing technology. To obtain a high-quality wood texture template for 3D printing, the sharpness of the wood texture was evaluated by image sharpness models, and the scanned wood texture was optimized by colorimetric parameter and sharpness adjustments. The wood texture coating, which was mainly composed of acrylated oligomers, was UV-inkjet 3D printed on the medium-density fiberboard (MDF) from an obtained template. The properties of the printed wood texture coating on the MDF, including its gloss, wearability, adhesion, and hardness, were measured. The results showed that a wood texture coating with high processability can be feasibly 3D printed on MDF to obtain comparable decoration using commercial products.

Smart Agriculture Using IoT Multi-Sensors: A Novel Watering Management System

Advances in the Internet of Things (IoT) are helping to make water management smarter and optimizing consumption in the smart agriculture industry. This article proposes a new topology of sensor nodes based on the use of inexpensive and highly efficient components, such as water level, soil moisture, temperature, humidity, and rain sensors. Additionally, to guarantee good performance of the system, the used transmission module is based on LoRa LPWAN technology. The design of the main circuit board of the system is optimized by combining two layers and implementing software optimization. The overall sensor network is developed and tested in the research lab, and real farms can be controlled by users manually or automatically using the mobile application. Experimental results are produced by testing sensor and communication link effectiveness, and are subsequently validated in the field through a one-week measurement campaign.

PCB DESIGN USING LOCAL TECHNOLOGY AND AutoCAD

This paper focuses on the production of printed circuit boards for use with both domestic and industrial electronics. The use of printed circuit board (PCB) design software, methods of design transfer to copper boards, etching and post-production tasks were undertaken and are described in detail in this paper. The relevance of this paper is appreciated for its unique ideas and methods of incorporating local technology into modern PCB design with proven reliability, precision and economic advantages.

Mathematical Modeling Of The Hydrodynamic Forces On A Vertical Cambered Slotted Otter Board

As an important accessory of single trawl, otter board directly affects net horizontal expansion, further the catching and fishing efficiency[1-2]. For improving the fishing efficiency and technology level and solving the world energy crisis in some way, the hydraulic performance is chosen and the effects of different structural parameters are studied. Such as aspect ratio, curvature, bending and receding angle, deflector angle and slot width, number of slots and so on[3-10]. This paper selects a vertical cambered slotted otter board as research object, presents a principle of hydrodynamic efficient based on the experiment data, then a mathematical model of the hydrodynamic efficient is obtained. This model has been found as a function of angles of attack and deflector, and is suitable for similar otter board design and optimization.

Design of magnetic board (F99) according to the methods of gradation to acquire and develop the intelligence of the blind ages (6-8) years

Design of magnetic board (F99) according to the methods of gradation to acquire and develop the intelligence of the blind ages (6-8) years

Using a High-Speed Mini-PC to Control an Autonomous Underwater Vehicle

In this paper, the authors present the design of a mini-PC board to fast processing of an AUV (Autonomous Underwater Vehicle) with two 360° rotational thrusters. This rotation capability in the thrusters, along with an embedded mass shifter, allows for long-time immersive motor maneuvers for this AUV. Also, the conditions for moving the device at the water surface and depth are provided by changing the angle of the thrusters and moving the mass shifter along with the motor speed change. All the commands related to the motor angles, proper position of the thrusters, mass shifter, and speed, are sent to an Engine board via a high-speed Mini PC. The high-speed Mini PC sends decisions to the Engine board after receiving and processing all sensors data as well as data from embedded cameras. This integrated system provides the ability to move safely based on accurate analysis of the environment by sensors and images received by cameras from the surroundings, with minimal energy consumption for the underwater AUV. The results of various tests demonstrated the high performance of this AUV.

Analysis and Design of High-Efficiency Parallel-Circuit Class-E/F Power Amplifier

In this paper, a single-ended parallel-circuit (PC) class-E/F power amplifier (PA) is proposed. For a particular case of the PC class-E/F3 mode with 50% duty cycle, its analytical derivation of the idealized waveforms, optimum values of the load network components, and significant figure-of-merit of PA is elaborated and verified. The ideal optimum voltage and current waveforms do not overlap simultaneously, which presents a theoretical drain efficiency of 100%. In addition, compared with other switch-mode PAs, the proposed structure successfully improves the performance in the peak drain voltage ( $V_{\mathrm {max}}$ ), maximum operating frequency ( $f_{\mathrm {max}}$ ), and power output capability ( $c_{p}$ ). Hence, it provides a good choice for high-efficiency mobile/wireless communication systems in the future. The analysis is validated by simulation and design of a test board. The measurement result shows the output power of 40.4 dBm, drain efficiency of 83.9%, power-added efficiency of 77.2%, and power gain of 10.4 dB at an operating frequency of 2.6 GHz.

High frequency realization of non-autonomous nonlinear transistor circuit

In this paper, an electronic implementation of a non-autonomous nonlinear transistor circuit is presented. This nonlinear circuit topology requires a minimal number of components, which consists of two resistors, two capacitors, and a single NPN bipolar junction transistor (BJT). This topology is of interest because it is relatively simple to construct and could be used for potential applications such as random number generators (RNGs) or noise signal generators (NSGs). The transistor portion of the circuit was analyzed using the Ebers-Moll model for a BJT. Using this model, time domain and phase space plots that qualitatively match the original systems dynamics were created. This model was also used to create bifurcation diagrams of the base voltage versus both frequency and amplitude, where periodic and chaotic solutions exist. The hardware realization was built using commercial-off-the-shelf (COTS) components with two different printed circuit board (PCB) designs. This PCB included the forcing function on the board with the transistor circuit. This circuit topology functioned over a wide range of frequencies, with an upper limit of approximately 5.1 MHz. Many potential applications could benefit from this high operation frequency.

Investigation of the Root Causes of Electromagnetic Noise of an Interleaved DC–DC Converter With GaN or Si Transistors and Corresponding Optimization Strategies

The proposed paper unveils various sources of conducted and radiated electromagnetic interferences (EMIs) of an interleaved dc-dc converter with gallium nitride (GaN) transistors and describes different optimization strategies. Instead of striving to achieve conformity to electromagnetic compatibility (EMC) standards, it rather focuses on deriving a deeper understanding of the source of EMI phenomena related to fast switching power converters generalizing critical aspects that need to be kept in mind during the design stage. The fast switching transients of GaN transistors are the main reason for increased EMI, which is why the characteristics of the applied transistors are investigated closely, paying special attention to the parasitic switching oscillations. Various observed interference effects are presented and corresponding conclusions are drawn. The effects are divided into intra-EMI issues of capacitive and inductive near-field coupling related to signal instability and inter-EMI issues of conducted and radiated noise. Based on these findings, different optimization strategies are presented addressing signal filtering, an optimized printed circuit board design, as well as proper high-frequency designs of passive components such as capacitors for the dc link and the power choke. All findings are put into context with the EMI characteristics of an equivalent dc-dc converter utilizing Si-insulated gate bipolar transistors (IGBTs).

Measurement of thermal conductivity of paper and corrugated fibreboard with prediction of thermal performance for design applications

Understanding heat transfer in corrugated fibreboard is important to the design of more effective packaging for industries which involve the freezing and chilling of food. In this work the thermal conductivity of papers which compose corrugated fibreboard were measured and used to validate finite element models of heat transfer in fibreboard. The results showed paper to be highly anisotropic, with thermal conductivity in the machine and cross machine directions being almost an order of magnitude larger than in the thickness direction. The finite element models showed good agreement with experimental results and demonstrated that the majority of heat transfer in corrugated fibreboard is though the fluted medium. Based on the finite element models, simple models for the prediction of the thermal performance of corrugated board were evaluated and shown to be very effective in reproducing the results of the more complex finite element methods. These simple methods can be used to perform corrugated fibreboard design calculations, and the models with and without radiation can be used to provide estimates of the lower and upper bounds of the thermal resistance for a given board design.

Initial public offering valuation and prior shared experience in the boardroom of threshold ventures: A study of industry effects

AbstractResearch question/issueWe explore the following question: How do initial public offering (IPO) investors value the existence of prior shared experience (PSE) between the CEO and the board of threshold ventures?Research findings/insightsBuilding on the resource provision role of the board, signaling, and the dynamics of decision making within teams literatures, our results show that extensive PSE between the CEO and the board is detrimental to IPO valuation because it augments the perceived risk of overconfidence and myopic decisions sending negative signals to investors. Yet, the industry diversity of that PSE and the level of industry ambiguity mitigate such negative signaling effects.Theoretical/academic implicationsWe make three main contributions to the literature. First, we make a specific contribution by advancing that extensive PSE between the CEO and the board is detrimental for IPO value, unless it is mitigated by the diversity of such PSEs across different industries. Our results therefore highlight boundaries within which previously accepted findings about the positive relationship between PSE and new venture performance do not hold. Second, we enrich our understanding of the relationship between board design and industry conditions by showing that investors perceive differently the extensiveness of PSE between the CEO and the board depending on the degree of industry ambiguity. Overall, we move beyond prior research on signaling, which has tended to focus on primary intended and costly signals, exploring signals with potential negative effects at IPO.Practitioner/Policy ImplicationsOur research has practical implications for ambitious entrepreneurial ventures trying to achieve high growth by going public in their early stages of development. Board compositions may commonly be transformed ahead of IPOs to send a signal to the potential investors about their effectiveness in meeting the strategic challenges of being in the public arena. Our findings suggest that entrepreneurs, pre‐IPO investors, and their advisors may need to adopt a fine‐grained approach to constructing effective boards at an early stage.

Modelling and optimisation algorithm for length‐matching escape routing of differential pairs

To improve the performance and signal integrity for printed circuit board designs, considering differential pairs in the escape routing is an important issue. Previous works use two-stage approaches, meeting points determining followed by differential pairs connecting, to generate a routing solution. However, existing approaches may produce either non-length-matching solutions or longer length-matching solutions. In this Letter, the authors propose an escape routing model with one-stage optimisation to simultaneously determine median points and route length-matching paths for all differential pairs. Experimental results show that their approach can significantly reduce maximum and average differential-pair skews with 100% length-matching results.

Phase Locked Loop System with SIW-based Bandpass Filter for D-band Microwave Interferometer

This paper presents the development and implementation of a low phase-noise stable signal generator for a D-band microwave interferometer application used in the fusion plasma diagnostics. A phase locked loop (PLL) circuit is designed to generate the stable frequencies of 2.3 and 2.333 GHz which is then up-converted to 6.9 GHz and 7 GHz as required by the interferometer system. Programmable synthesizer with temperature compensated crystal oscillator (TCXO) is used to develop the PLL. In order to remove the higher order harmonics generated from the system, a substrate integrated waveguide (SIW) based bandpass filter is proposed which offers a low insertion loss with compact size. The proposed bandpass filter is designed and simulated in high-frequency structure simulator (HFSS) software. The bandpass filter provides pass band for frequencies ranging from 6.8 GHz to 7.2 GHz with an insertion loss of 0.5 dB and a return loss more than 25 dB. ADsim PLL software is used to derive PLL parameters and Altium software is used for the printed circuit board (PCB) design. Measured results are in consensus with the requirement of the interferometer system.

Securing Printed Board Performance and Assembly Reliability in Automotive Applications through IPC Standards

<div class="section abstract"><div class="htmlview paragraph">Industry consensus developed IPC standards for the automotive electronics manufacturer have been available since 2016. We will look at the current IPC standards available in development and in revision, the standards development process, and the automotive application addendums for printed board fabrication and assembly soldering that provide unique criteria for the reliability of electronic interconnects that must survive the harsh environments within the automotive industry. Attention will be given to a new effort in development to provide links between existing automotive-centric IPC standards and other industry standards applicable to automotive applications for printed board material selection, design, and solder joint reliability testing. We will also discuss challenges facing the industry, including process changes and cleanliness requirements, e.g. ionic contaminants, that affect every manufacturer and customer.</div></div>