Printed Circuit Board Research Articles

Design and Development of Sensing Unit for Wire Rope Tester

In this work, a sensing unit on a Printed Circuit Board (PCB) has been designed to house hall sensors. Hall sensors are used to capture leakage flux signals from magnetized wire ropes for Non-Destructive Testing (NDT) of wire ropes. Various parameters are optimized before designing PCB, such as: Lift-off, orientation of sensor, number of hall sensors. Hall sensor signals are captured using DAQ card of NI® and program is written in LABVIEW® software. System is designed for: reducing noise in acquired signal (using RC filter), decreasing the number of channels for data acquisition system, reducing system cost and maintain signal fidelity.

A rigidly foldable and reconfigurable thick origami antenna.

A rigidly foldable and reconfigurable origami antenna is developed here. This antenna uses thick folding panels thereby providing robust operation and folding/unfolding actuation, which are very important for many applications in extreme environments, such as space. Also, this antenna can be constructed using standard printed circuit boards, which simplifies its manufacturing. For the reconfigurable antenna developed here, the origami flasher pattern is chosen to achieve a spatial transformation of a dipole operating at 0.48 GHz to a conical spiral antenna (CSA) operating from 2.1 to 3.7 GHz. The design equations for the origami CSA are derived. A prototype is built using a 0.81-mm-thick FR4 substrate to validate the proposed methodology. The antenna parameters are investigated in a wide frequency range. Our simulated results agree very well with the measurements. The rigid structure of the proposed design and its reconfigurable nature make it a good candidate for satellite communications.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Intrinsic Metal Component-Assisted Microwave Pyrolysis and Kinetic Study of Waste Printed Circuit Boards

Waste printed circuit boards (WPCBs) hold great recycling value, but improper recycling can lead to environmental issues. This study combines pyrolysis and microwave technologies, leveraging the unique phenomenon where metal materials tend to “spark” in a microwave field, to develop a microwave pyrolysis process for WPCBs that incorporates metal fillers. The research analyzes the effects of microwave power, metal filler addition, and pyrolysis time on the efficiency of microwave pyrolysis. It explores the mechanisms of microwave pyrolysis and the pathways of pyrolysis product formation, and the kinetics of the pyrolysis reaction of WPCBs. The results indicate that microwave-assisted pyrolysis greatly improves efficiency. Within the experimental range, the optimal conditions are found to be a microwave power of 1600–1800 W, a metal filler addition of 10%, and a pyrolysis time of 10 min. Under these conditions, the yield of pyrolysis liquid was 12.8%, with approximately 5–12 different components, while the yield of pyrolysis gas was 12.7–13.4%, with about 9–11 different components. Compared to conventional pyrolysis products, the liquid products from microwave pyrolysis are simpler and more advantageous for resource utilization. Theoretical calculations show that the average activation energy for the microwave pyrolysis process is 81.05 kJ/mol, with an average reaction order of 0.93, which is greatly better than the 147.75 kJ/mol of the conventional pyrolysis process.

Design and implementation of AEM10941 based solar energy system harvester for domestic lighting as a sustainable lighting solution for rural areas

Lack of access to reliable and affordable electricity in Mbo’o community and the reliance on kerosene lamps for lighting has impacted various aspects of daily life in the area such as education, health, safety and economic productivity. Yields rural exodus and poverty. The aim of this research is to address the challenge of inadequate lighting in the Mbo’o community by developing a sustainable and affordable solution using the AEM10941 solar lamp and thus improving the quality of life for community members and reducing environmental impacts. The methodology involved utilizing the AEM10941 and connecting it with an ATMEGA328pu, switch and LED to construct the lamp. This included configuring the AEM10941, designing the printed circuit board for the lighting and control circuits, and then crafting the lamp casing. The lamp was designed to operate in two modes including indoor and outdoor/security modes. Performance evaluation tests revealed that the AEM10941 effectively charges the battery to full capacity within three hours. Additionally, in indoor mode, a single charge can sustain up to 10 h of lighting, demonstrating the lamp’s efficiency and reliability in providing prolonged illumination. At full brightness, the lamp produced an illuminance of 1436 lx. the AEM10941 based solar lamps performance characteristics including illumination intensity, runtime and charging time are in accordance with the standards values and even above. This sustainable way of lighting is the convenient solution to improve the general living standard of the Mbo’o community. The key contribution of this work is the development of a sustainable, affordable and versatile solar lamp tailored to the specific needs of the Mbo’o community. This work provides an innovative solution to address the community’s reliance on kerosene lamps, thereby potentially reducing emissions while improving safety and quality of life.

Applying Circular Thermoeconomics for Sustainable Metal Recovery in PCB Recycling

The momentum of the Fourth Industrial Revolution is driving increased demand for certain specific metals. These include copper, silver, gold, and platinum group metals (PGMs), which have important applications in renewable energies, green hydrogen, and electronic products. However, the continuous extraction of these metals is leading to a rapid decline in their ore grades and, consequently, increasing the environmental impact of extraction. Hence, obtaining metals from secondary sources, such as waste electrical and electronic equipment (WEEE), has become imperative for both environmental sustainability and ensuring their availability. To evaluate the sustainability of the process, this paper proposes using an exergy approach, which enables appropriate allocation among co-products, as well as the assessment of exergy losses and the use of non-renewable resources. As a case study, this paper analyzes the recycling process of waste printed circuit boards (PCBs) by disaggregating the exergy cost into renewable and non-renewable sources, employing different exergy-based cost allocation methods for the mentioned metals. It further considers the complete life cycle of metals using the Circular Thermoeconomics methodology. The results show that, when considering the entire life cycle, between 47% and 53% of the non-renewable exergy is destroyed during recycling. Therefore, delaying recycling as much as possible would be the most desirable option for minimizing the use of non-renewable resources.

Analysis and Design of High Power Density Flyback Converter

ABSTRACTThis paper presents a flyback converter with high efficiency and high power density. An optimal design method for high power density planar transformers is presented. Applying the principle of flux cancellation, a matrix transformer that originally needed an independent magnetic core was integrated into a single magnetic core to reduce the volume of the core. This method effectively reduces the printed circuit board (PCB) layer number of the planar transformer and increases the possibility of the application of the planar transformer in the flyback converter. An optimized design method of the winding structure is given according to that model to further reduce the winding loss of the transformer. Meanwhile, the proposed structure is verified by finite element analysis software. Finally, a multi‐output flyback converter with a frequency of 100 kHz is designed to verify the practical performance of the proposed transformer.

Microwave absorber surface design for 5G energy harvesting applications

This study presents a high-efficiency microwave absorber for energy harvesting in 5G frequencies. Initially, a unit cell was designed in four stages to efficiently absorb in the targeted frequency region. The results obtained for each stage of the design were analyzed, and additional investigations were conducted for substrate material and thickness based on the optimum performance of the unit cell structure. A unit cell absorber designed on an FR4 a flame-resistant fiberglass/epoxy-based composite, commonly utilized in printed circuit boards due to its favorable electrical insulation properties and low cost. With a thickness of 1.5 mm, the absorber achieved a 98.04% absorption at 3.8 GHz according to simulation results. Subsequently, this unit cell was separately designed and simulated with different periodic arrays to transform into an absorber surface. As a result, high absorption rates of 98.94% and 98.35% were achieved at 3.8 GHz and 4.2 GHz, respectively, in the 2 × 2 array. It was observed that the structure absorbs over 85% within a 1 GHz bandwidth between 3.5 GHz and 4.5 GHz. Finally, a prototype of the absorber surface was manufactured, and measurements were taken in the laboratory environment. Significant agreement was found between the data obtained from these measurements and the simulation results. The results indicate that the suggested absorber surface is well-suited for energy harvesting within the n77 (3.3 GHz to 4.2 GHz) and n78 (3.3 GHz to 3.8 GHz) bands of 5G communication.

Optimization of Coreless PCB Coils Based on a Modified Taguchi Tuning Method for WPT of Pedelec

The printed circuit board (PCB) winding coil offers advantages such as small size, high precision, high repeatability, and low cost, making it conducive to the miniaturization of electronic equipment and a popular choice in wireless power transmission systems. This paper aims to clarify the correlation between induction parameters and inductive capabilities using the orthogonal array of the modified Taguchi method for Pedelec applications. The conventional Taguchi method typically achieves only local optimization; however, this paper considers practical application conditions and combines experimental data to establish the initial values of the orthogonal array, thereby achieving global optimization. Additionally, the tuning process of the Taguchi method replaces physical experiments with simulations, enhancing optimization speed and reducing hardware implementation costs. The performance index for the proposed modified Taguchi tuning method is selected as a combination of the quality factor (Q) and coupling coefficient (k) to minimize AC resistance and improve system efficiency. To validate the proposed method, the designed coils were implemented and tested in a WPT system based on S–S compensation with a half-bridge topology. The experimental results demonstrate that the optimized PCB coil parameters derived from the proposed tuning method accurately validate the method’s effectiveness and accuracy. From the measured results with the proposed modified tuning method, the system efficiency is increased by 43.87% and the system transmitting power is increased by 28.51%.

Compact Substrate Integrated Waveguide Cubical Dielectric Resonator Antenna for fifth-generation applications

A comprehensive analysis of a wideband Cubical Dielectric Resonator Antenna is presented, specifically designed for 5G-NR wireless communication applications, focusing on the N257, and N258 frequency bands. This antenna exhibits symmetrical radiation patterns, a wider bandwidth, improved efficiency, and substantial gain characteristics. The design employs a low-loss substrate-integrated waveguide structure to enhance gain while reducing cross-polarization effects. This is accomplished through an innovative approach of establishing boundary conditions using copper wire stitching for vias, superseding the conventional soldering iron method, which guarantees minimal radiation leakage, compact dimensions, and reduced losses. The perforated dielectric resonator antenna possesses higher mode excitations, and implementing metallic strips on two resonator surfaces facilitates the simultaneous excitation of fundamental and higher-order modes, thereby yielding a broadband response. The overall dimensions of the antenna are 15.29 × 8.42 × 3.8 mm3(1.3×0.7×0.3)λ03, which facilitates a measured impedance bandwidth of 8.2 GHz, spanning from 24.4 to 32.6 GHz (28.7%), accompanied by a high gain of 8.1 dBi and efficiency levels reaching up to 94%. The prototype is constructed utilizing the standard printed circuit board technique, and simulation outcomes are derived using the High-Frequency Structure Simulator (HFSS).

Conductive paths generation using topology optimization for worst-case thermal design in space systems

Designing thermal systems for space platforms is a challenging task due to the wide variability in thermal conditions during the orbit and the strict constraints imposed by other subsystems. Several strategies have been developed to address these challenges while minimizing the thermal control subsystem’s signature, encompassing different algorithms optimize components positions in the platform. When relocation is not possible, thermal couplings between components can be modified to enhance heat transfer and achieve more uniform temperature distribution. To design optimal thermal paths in 2D space structures, in this paper a topology optimization framework based on the Heaviside Projection Method is introduced, using the Lumped Parameter Method (LPM) and taking the radiation heat transfer into account. The algorithm’s performance is tested on a Printed Circuit Board (PCB) by designing an optimal copper layer to meet specific thermal requirements under both extreme hot and cold conditions. Results show a significant improvement in thermal compliance for all components with the addition of this high-conductivity layer. Additionally, a reduction method is introduced to transfer the material distribution from the optimization to a coarser mesh of any size, which is useful to facilitate its implementation in existing software, where a large number of degrees of freedom can be a limitation.

Gold removal from e-waste using high-intensity focused ultrasound

The demand for rare and precious metals (RPMs), e.g. gold, is increasing, as these are used in the ever-increasing amount of electronics needed for technological development and digitalization. Due to their rarity, virgin mining of RPMs is becoming more difficult and expensive. At the same time, over 62Mt of e-waste is created globally each year. The high concentration of gold and other RPMs in e-waste makes it an excellent source for recycling. Unfortunately, current recycling methods need to separate the different metals and the current pyrometallurgical and hydrometallurgical processes also create toxic pollutants, large amounts of wastewater and require highly corrosive substances. Here we present a new method for gold removal for the purpose of recycling, using only water and high-intensity focused ultrasound to induce material erosion through cavitation. An 11.8 MHz ultrasonic transducer is used to first image the sample to locate gold-coated pads on discarded printed circuit boards (PCBs) and subsequently to remove only the gold layer. We demonstrate that the gold removal can be controlled by the number of transmitted ultrasonic bursts and that the energy efficiency is optimal when only minute amounts of the nickel layer beneath are also removed. Removing solely the gold layer also decreases the need for further processing steps. This greener gold removal method for e-waste is therefore well aligned with, and contributing to, the United Nations Sustainable Development Goal 12: Ensure sustainable consumption and production patterns.

YOLO-HLT: improved lightweight printed circuit board surface defect detection algorithm based on YOLOv5

YOLO-HLT: improved lightweight printed circuit board surface defect detection algorithm based on YOLOv5

GaN-HEMT Power Module of Aluminum-Clad Printed Circuit Boards for Small Power Loop Inductance and High Cooling Performance

GaN-HEMT Power Module of Aluminum-Clad Printed Circuit Boards for Small Power Loop Inductance and High Cooling Performance

Analytical Electro-Thermal Model and 3-D Thermal Resistance Network for SMD-Based Printed Circuit Board Power Converters

Analytical Electro-Thermal Model and 3-D Thermal Resistance Network for SMD-Based Printed Circuit Board Power Converters

A wearable sign language translation device utilizing silicone-hydrogel hybrid triboelectric sensor arrays and machine learning

Sign language is a crucial communication tool for the hearing impaired to interact with the outside world. However, the low prevalence of sign language leads to significant communication barriers between the hearing impaired and others. These barriers can be alleviated by using electronic sign language translation devices, but such devices typically face challenges related to their bulkiness, rigidity, and high cost. Herein, we present a cost-effective, flexible, and wearable device designed for the interpretation of sign language, leveraging machine learning algorithms to transform sign language movements into spoken language accurately. Our device is equipped with flexible and stretchable triboelectric sensor (FS-TS) arrays and a printed circuit board for efficient signal processing and wireless transmission. These FS-TSs are constructed from cost-effective materials including silicone, hydrogel, and fluorinated ethylene propylene (FEP) powders, which, while affordable, ensure rapid response and heightened sensitivity. By analyzing 1,000 sets of sign language gestures with machine learning, our system has achieved an impressive recognition accuracy of 98.5%. This achievement underscores the potential of our system as an economically viable and scalable solution for enhancing sign language recognition within the wearable electronics domain.

The Added Value of Copper and Silver Metal from Printed Circuit Boards Waste Using Davis Tube with Variations of Size and Magnetic Intensity

The widespread use of electronic devices has led to a significant increase in electronic waste, including PCB (printed circuit board) waste. PCBs contain valuable metals like copper and silver, which can be reclaimed and reused. Recently, there has been a growing demand for urban mining processes to extract electronic waste PCB Flame Retardant-2 (FR-2) from laptops and computers. During the urban mining process, PCB FR-2 waste undergoes various physical treatments such as dismantling, crushing, and concentration processes. One of the concentration processes involves magnetic separation using a Davis tube. This study aims to investigate the effects of size and magnetic intensity variations on the recovery of copper and silver levels in FR-2 PCB waste. The magnetic concentration process was carried out using different size ranges (-63+100#, -100+150#, -150#) and magnetic intensities (1000 G, 2000 G, 3000 G). The results indicated that the most effective size for separating copper and silver is -63+100# and the optimal magnetic intensity is 1000 G. This resulted in copper and silver content of 45.66% and 0.162%, with recoveries of 80.135% and 62.505% respectively.

Hybrid inspection of printed board defects

Objectives. A hybrid approach to the problem of searching and classifying defects in printed circuit boards (PCB) is proposed. Key factors and trends in the design and production of PCBs are considered. The relevance of the study is determined by the use of new materials and production technologies.Methods. A hybrid approach based on the algorithm of comparison with reference and the use of the YOLO family of neural network models for detecting objects is used to solve the problem.Results. Models were trained on public sets of PCB images with six classes of defects, and their accuracy was assessed using generally accepted metrics.Conclusion. Experiments have shown that the YOLOv8 neural network architecture has high accuracy of defect detection, low sensitivity to image quality, presence of text and graphic objects on the PCB, but the low quality of training datasets imposes restrictions on the use of only neural networks for defect detection. It is proposed to use a hybrid approach to improve the quality of defect inspection by applying different methods depending on the quality assessment of the analyzed images.

Exploring Sustainable Construction: Utilizing Printed Circuit Board Waste as a Partial Sand Replacement in Concrete Production

The escalating demand for concrete in construction, coupled with the environmental degradation caused by sand extraction, necessitates the exploration of alternative materials for sustainable construction practices. This study investigates the potential of utilizing Printed Circuit Board (PCB) waste as a partial replacement for sand in concrete production. This investigation is presented through experimental work to replace the sand by 10%, 20%, and 30% by volume. The applicability of the proposed mixes is demonstrated through a comparative analysis of the concrete fresh and hardened properties. This research contributes to the field of sustainable construction by offering a novel use for electronic waste, thereby mitigating the environmental impact of both the electronics and construction industries.

Use of electrodialysis to produce and recycle on-site raw materials for waste printed circuit board recycling process. I. HBr and KOH electrosynthesys

Use of electrodialysis to produce and recycle on-site raw materials for waste printed circuit board recycling process. I. HBr and KOH electrosynthesys

Digital Active EMI Filter for Smart Electronic Power Converters

Electronic power converters are widespread and crucial components in modern energy scenarios. Beyond mere electrical energy conversion, their electronic structure allows several functionalities to be naturally embedded in them, including energy management, diagnosis, communication, etc. The operation of the converter itself, or the system interfaced by the same, commonly produces undesired electromagnetic interferences (EMIs) that should comply with prescribed limits. This paper presents a digital active EMI filter designed to mitigate such disturbances. The proposed hardware implementation can acquire and analyze the common-mode (CM) noise affecting the circuit and inject a compensation signal to attenuate the measured interference. A novel adaptive algorithm is introduced to compute the necessary signals for effective noise cancellation. The implementation is integrated within a single printed circuit board interfaced with a field-programmable gate array (FPGA) running the control algorithm. The digital filter’s efficacy in EMI reduction is demonstrated using a synchronous buck converter with gallium nitride (GaN) power devices, achieving significant noise reduction. Additionally, potential functionalities are envisioned to fully exploit the capabilities of the proposal beyond EMI filtering, like fault detection, predictive maintenance, smart converter optimization, and communication.