Printed Circuit Board Lines Research Articles

Identifying and Modeling Resonance-Related Fluctuations on the Experimental Characteristic Impedance for PCB and On-Chip Transmission Lines

It is well known that the fluctuations in experimentally obtained characteristic impedance versus frequency curves are associated with resonances originated by standing waves bouncing back and forth between the transitions at the transmission line terminations. In fact, microwave engineers are aware of the difficulty to completely remove the parasitic effect of these transitions, which makes obtaining smooth and physically expected frequency-dependent curves for the characteristic impedance a tough task. Here, we point out for the first time that these curves exhibit additional fluctuations within the microwave range due to standing waves taking place within the transition itself. Experimental verification of this fact was carried out by extracting this fundamental parameter from measurements performed on on-chip and printed circuit board (PCB) lines using probe pad adapters and coaxial connectors. We demonstrate that the lumped circuit approach to represent the transitions lacks validity when the additional fluctuations due to the connectors become apparent, and we propose a new model including transmission line effects within the transition.

D-Band Air-Filled Substrate Integrated Waveguide (AFSIW) and Broadband Stripline to AFSIW Launcher Embedded in Multi-Layer PCBs

We report <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D$</tex-math> </inline-formula> -band air-filled substrate integrated waveguides (AFSIWs) with solid copper sidewalls fabricated inside a multi-layer printed circuit board (PCB) with broad wall width of 1.6 mm and cavity height of 300 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> m. Measurements show a loss of 0.07–0.08 dB/mm across 115–155 GHz. This result is the first demonstration of an AFSIW above 100 GHz in a low-cost mass manufacturable PCB and has the lowest loss compared to reported planar PCB lines or substrate integrated waveguides (SIWs) in PCBs and Interposers. We also introduce a broadband stripline to the AFSIW launcher using a broad wall transverse slot which offers ease of manufacturability over existing transitions having a measured insertion loss of 1.1 dB and 27% bandwidth. The combination of a low-loss AFSIW and wideband launcher allows both striplines and AFSIWs to coexist in the same multi-layer PCB.

Predicting the printed circuit board cycle time of surface-mount-technology production lines using a symbiotic organism search-based support vector regression ensemble

This paper presents a symbiotic organism search (SOS)-based support vector regression (SVR) ensemble for predicting the printed circuit board (PCB) cycle time of surface-mount-technology (SMT) production lines. Being able to predict the PCB cycle time accurately is essential for optimising the SMT production schedule. Although a machine simulator can be reliably used for single-type PCB production, it is time-consuming and often inaccurate for the simulator to be applied for highly mixed orders in multiple flexible SMT production lines. Due to the dynamic changes in both PCB orders and SMT production lines, there is a diverse set of samples, but the size of similar samples is relatively small. An SVR model is therefore used to estimate the PCB cycle time, and the SOS algorithm is employed to optimise the SVR parameters. We assume that uncertainties during the assembly process can be captured by the characteristics of PCB and SMT lines, which are utilised as features to train the SVR model. To enhance the performance of the prediction accuracy, an SOS-SVR ensemble is proposed. Experiments based on datasets collected from a leading global electronics manufacturer confirm the efficiency of the proposed approach compared to industrial solutions currently in place and other machine learning methods.

Smart Line Judgement System: A Novel Technology in Vol-leyball Arbitration

&lt;p class="BodyText1"&gt;Within previous decade, sensitivity to arbitration systems in sports such as soccer, tennis and volleyball has been sharply increased and technicians turned to new technologies to fulfill the demands for a reliable judgement. The main purpose of this study was to address a new method in judgement of presence of ball in the volleyball field in the shortest possible time by manipulation of lines surrounded the field and the ball layer’s structure. A carbon semi- conducting fabric layer designed ball was thrown to the printed circuit board (PCB), which have replaced the surrounded field lines. The ball was thrown in six different angles of 15, 30, 45, 60, 75, and 90 degrees and with 20 and 40 m.s-1 speed. As soon as the semiconducting ball hits the PCB lines, the LED, which embedded under the PCB, turns on and announce the presence of the ball in the field. In 20 m.s-1 speed, the PCB detected 97.1% of ball presence in the field per 1500 trials six angles. Almost similar, in 40 m.s-1 speed, the accuracy of PCB in hit detection was 97.6% per 1500 trails. Additionally, regardless of ball speed, the more perpendicular the ball hit the PCB line, the accurate detection was made. The smart line judgment system could be a reliable, efficient, and affordable technology that provide referees with an accurate decision and athletes with a faster game flow. &lt;/p&gt;

Miniaturized Printed Inverted-F Antenna for Internet of Things: A Design on PCB with a Meandering Line and Shorting Strip

This paper focuses on a printed inverted-F antenna (PIFA) with meandering line and meandering shorting strip under 2.4 GHz industrial, scientific, and medical (ISM) band for Internet of things (IoT) applications. Bluetooth Low Energy (BLE) technology is one of potential platforms and technologies for IoT applications under ISM band. Printed circuit board (PCB) antenna commonly used in commercial and medical applications because of its small size, low profile, and low cost compared to low temperature cofired ceramic (LTCC) technology. The proposed structure of PIFA is implemented on PCB to gain all these advantages. Replacing conventional PCB line in PIFA by the meandering line and meandering shorting strip improves the efficiency of the PIFA as well as the bandwidth. As a case study, design and measurement results of the proposed PIFA are presented.

The effect of epoxy/glass interfaces on CAF failures in printed circuit boards

Reductions in printed circuit board line spacing and via diameters and the increased density of vias with higher aspect ratios (ratio between the thickness of the board and the size of the drilled hole before plating) are making electronic products increasingly more susceptible to material and manufacturing defects. One failure mechanism of particular concern is conductive anodic filament (CAF) formation, which typically occurs in two steps: degradation of the resin/glass fiber bond followed by an electrochemical reaction. Bond degradation provides a path along which electrodeposition occurs due to electrochemical reactions. The path can result from poor glass treatment, from the hydrolysis of the silane glass finish, or from mechanical stresses. Once a path is formed, an aqueous layer, which enables the electrochemical reactions to take place, can develop through the adsorption, absorption, and capillary action of moisture at the resin/fiber interface. This paper describes the concerns with CAF and the methods used for analyzing low-resistance failures. A case study is then given which highlights problems that arose on a commercial circuit board material used by a major telecommunications provider.

A System-Level Electrostatic-Discharge-Protection Modeling Methodology for Time-Domain Analysis

A system level modeling methodology is presented and validated on a simple case. It allows precise simulations of electrostatic discharge (ESD) stress propagation on a printed circuit board (PCB). The proposed model includes the integrated circuit (IC) ESD protection network, IC package, PCB lines, passives components, and externals elements. The impact of an external component on the ESD propagation paths into an IC is demonstrated. Resulting current and voltage waveforms are analyzed to highlight the interactions between all the elements of an operating PCB. A precise measurement technique was designed and used to compare with the simulation results. The model proposed in this paper is able to predict, with good accuracy, the propagation of currents and voltages into the whole system during ESD stress. It might be used to understand why failures occur and how to fix them with the most suitable solution.

차량용 무선 비디오 시스템 내 EMI 노이즈 개선 방안

본 논문은 EMI(Electro Magnetic Interference) 잡음의 주된 원인인 각 회로의 임피던스 부정합, 고속 데이터 인터페이스 그리고 PCB(Printed Circuit Board) 상에서 전원/접지 구조에 의한 불안정 잡음을 주파수 대역별로 분석하여 각 원인별 잡음 개선 방안을 제시하였다. 또한 이를 통해 무선 비디오 데이터를 전송하는데 사용되는 차량용 무선 비디오 스트림 시스템 설계방안을 제안하였다. 잡음 개선 방안으로 회로 신호의 임피던스 정합과 PCB 라인의 내층 설계, 전원/접지 구조 개선을 통해 시스템의 잡음 개선을 수행하였다. 구현된 시스템은 EMI 규제에 따라 각 대역에서 40[dBuV/m]와 47[dBuV/m]내로 잡음 개선을 하였다. In this paper, we analyzed various noise in the video stream system that have largely influence on EMI noise. We presented the remedy for these various noises and then designed the wireless video streaming system for a vehicle. To minimize EMI noise, we derived the improvement of noise characteristic from impedance matching, new design of the inner layer of the PCB line design and new design of high-speed data Interfaces. As a result, the final system showed 40[dBuV/m] and 47[dBuV/m] dB in the each regulation band.

A Conceptual Framework of an Advanced Planning and Scheduling System for Printed Circuit Board Manufacturing Lines

Advanced planning and scheduling (APS), which is one of the most advanced technologies in manufacturing management applications, is emerged to resolve the shortcomings of enterprise resource planning (ERP) systems and manufacturing execution systems (MES) as a planning and scheduling tool. In this paper, we suggest a conceptual design of an APS system, specific for printed circuit board (PCB) manufacturing lines. In general, the PCB line can be regarded as a hybrid flow shop in which there are serial workstations, each with unrelated parallel machines, and has special characteristics such as complex and re-entrant flows, high and sequence-dependent setup times, subcontracting in the operation level, etc. Although there are a number of commercially available APS packages, they are not directly applicable to the PCB lines due to these characteristics. Therefore, we suggest a new conceptual design of APS, called PCB-APS in this paper, which consists of five modules: work module, simulation run module, dispatching rule generation module, simulation model generation module, and master data input module. The PCB-APS suggested in this paper considers the characteristics of the PCB lines in more details, and hence can improve the system performances significantly.

Optimal cyclic scheduling for printed circuit board production lines with multiple hoists and general processing sequence

We introduce a mixed-integer programming formulation for finding optimal cyclic schedules for printed circuit board lines with multiple hoists on a shared track, where the processing sequence may be different than the location sequence of the tanks. Computational results on some benchmark problems indicate that optimal cyclic schedules for problems of realistic size can be found in a reasonable time.

An intelligent decision support environment for PCB assembly

Journal of Electronics ManufacturingVol. 04, No. 02, pp. 89-99 (1994) PAPERSNo AccessAn intelligent decision support environment for PCB assemblyCHONG CHIN SOON, ROBERT DE SOUZA and ANIRUDHA SENCHONG CHIN SOONGintic Institute of Manufacturing Technology, Singapore Search for more papers by this author , ROBERT DE SOUZASchool of Mechanical and Production Engineering, Nanyang Technological University, Singapore Search for more papers by this author and ANIRUDHA SENGintic Institute of Manufacturing Technology, Singapore Search for more papers by this author https://doi.org/10.1142/S0960313194000110Cited by:1 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractAn intelligent integrated environment that provides decision support for printed circuit board (PCB) assembly is presented. This simulation-based decision support system enables manufacturing engineers, with little or no simulation experience, to exploit this technology fully for design and management of PCB assembly lines. PCB lines are selected for their simplicity in representation but stochasticity in nature of product demand and change. Within the environment is the capability to design graphically simulation models mapped to the real system, to define desired production targets, to execute a base language model and to generate results that can be intelligently analysed and presented for remedial action. A case example is also presented.Keywords:PCBassemblysimulationSIMANintelligent FiguresReferencesRelatedDetailsCited By 1INTELLIGENT SIMULATION ENVIRONMENT FOR PRINTED CIRCUIT BOARD ASSEMBLYSK AHAD ALI, ROBERT DE SOUZA and ARUN KUMAR7 April 2012 | Journal of Electronics Manufacturing, Vol. 09, No. 04 Recommended Vol. 04, No. 02 Metrics History Received 1 March 1994 Accepted 1 April 1994 KeywordsPCBassemblysimulationSIMANintelligentPDF download

The “Orchard” scheduler for manufacturing systems

This paper describes Orchard, which is a heuristic algorithm for scheduling the loading of jobs into a manufacturing system. While Orchard was specifically designed for use at a particular printed circuit board line, it is sufficiently generic to be used at other manufacturing systems as well. In general, such a manufacturing system performs several operations on each job with multiple machines performing each operation. The routing of each job may involve stochastic branching including rework loops, and there may be a need to assign human operators to operations. The Orchard heuristic can be adapted to two different objective functions: weighted mean flow time, and an objective specially formulated for the circuit board line. The present paper describes all aspects of Orchard except its operator assignment module (which is described in another paper) and concludes with results of tests of the algorithm as applied to the circuit board line.

New Chemistries for Advanced Printed Circuit Board Fabrication

The relentless demand for enhanced electronics processing capabilities is causing major changes in all sectors of the electronics industry, particularly in interconnection and packaging. Printed circuit board line widths and hole diameters are decreasing and new substrate materials are finding increasing use. In addition, newer high density interconnection and packaging techniques such as multi‐chip modules, chip on board and TAB are beginning to move into production. These developments are placing new demands upon PCB manufacturers, who are in turn driving their process suppliers to provide the enabling chemistries. These demands have, for example, encouraged the development of high resolution electrophoretically deposited photoresists, photoimageable solder masks and the chemical deposition of solder from solution. However, against this requirement for improved and new processing chemistries there are growing environmental pressures which have necessitated changes in both materials and processing methods, a typical example being the growing interest in direct plating of via holes. This paper reviews the challenges and opportunities in advanced PCB fabrication from a processing chemical supply perspective and discusses the new processes and chemistries that will enable the PCB industry to produce state‐of‐the‐art boards in an environmentally acceptable manner.