Surface Mount Devices Research Articles

Anomaly Detection through Grouping of SMD Machine Sounds Using Hierarchical Clustering

Surface-mounted device (SMD) assembly machines refer to production lines that assemble a variety of products that fit their purposes. As the required products become more diverse, models that oversee product anomaly detection are also becoming increasing linearly. In order to efficiently oversee products, the number of models has to be reduced and products with similar characteristics have to be grouped and overseen. In this paper, we show that it is possible to handle a large number of new products using latent vectors obtained from the autoencoder model. By hierarchically clustering latent vectors, the model finds product groups with similar characteristics and oversees them by group. Furthermore, we validate our multi-product operation strategy for anomaly detection with a newly collected SMD dataset. Experimental results show that the anomaly detection method using hierarchical clustering of latent vectors is a practical management method for SMD anomaly detection.

Near-Field Coupling Effect Analysis of SMD Inductor Using 3D-EM Model

In this paper, we propose a methodology for analyzing the near-field coupling between two surface mount device (SMD) inductors using a 3-dimensional electromagnetic (3D-EM) model. To develop the 3D-EM model, we first constitute the equivalent circuit of the SMD inductor from the measured impedance and derive the loss tangent using circuit parameters. Secondly, the loss tangent using damped harmonic oscillator model is introduced to extract the effective permeability of core magnetic material in the SMD inductor. The optimization algorithm is used to compare the two loss tangents. Then the effective permeability is used in the magnetic material for the 3D-EM modeling of the SMD inductor. The validity of the proposed 3D-EM model is confirmed by comparing the impedance and S-parameters obtained from both measured and EM-simulated values for the two near-field coupled SMD inductors. Finally, the near-field coupling effects between the two adjacent SMD inductors are visualized in terms of coupling path visualization (CPV) using the proposed 3D-EM model, which demonstrates its usefulness for near-field coupling analysis.

Chemical Characterization of an ARDUINO® Board and Its Surface Mount Devices for the Evaluation of Their Intrinsic Economic Value

The remarkable technological development observed in recent decades has led to an exponential increase in the production of electrical and electronic devices. Regardless of their field of application or the type of device, electronic boards are a common feature of all these devices. For this reason, electronic boards represent a constant in electrical and electronic equipment waste. Knowing their composition and intrinsic economic value is essential for identifying sustainable disposal and valorization processes. In the literature, several articles report typical compositions of electronic boards, but it is rare to find a component-by-component characterization. This procedure is important to determine the components that need to be removed to increase the recovery yields of materials or to identify components with high concentrations of hazardous substances. For this reason, in this scientific article, we propose to examine the chemical composition of all the components of the Arduino® electronic board using advanced chemical analysis techniques. Arduino is a popular electronic board mainly used to prototype electronic projects rapidly. The chemical composition of the Arduino board has yet to be entirely determined to date. The decision to use the Arduino board is due to the fact that this board is widespread globally and could represent a reference study.

An efficient SMD-PCBA detection based on YOLOv7 network model

Modern Printed Circuit Board Assembly (PCBA) manufacturing processes require more accurate and robust defect inspection methods. Despite the potential of deep learning algorithms in PCBA defect detection, their ability to handle environmental factors and multi-modal data is still limited. To overcome this, we propose an improved YOLOv7-based network model that enhances the detection performance of densely distributed multi-size Surface Mount Devices (SMD) in multi-modal PCBA. Specifically, the proposed model enhances feature representation by designing a detection head based on Coordinate Attention, and incorporates feedback connections in the feature fusion stage to improve feature recognition through low-level propagation. Additionally, we propose the SEIoU loss function to calculate position loss between the prediction box and the ground truth, resulting in superior regression accuracy of the anchor box and improved detection accuracy. We validate the effectiveness and improvement of our proposed method through ablation experiments and algorithm comparison. Our proposed model outperforms the baseline YOLOv7 model with a 2.1% increase in mAP@0.5 for the multi-modal PCBA dataset and a 4.5% increase in mAP@0.5:0.95 for the VOC 2012 dataset, and a 1.0% increase in mAP@0.5:0.95 for the COCO 2017 dataset. Our study’s results suggest that our proposed model is a promising alternative to existing methods for detecting PCBA defects, as it accurately detects multiple tiny components amidst complex backgrounds, effectively identifies diverse types of defects, and remains lightweight.

Effect of flux activator in reflow process related flux residue on the climatic reliability of surface-mount electronic devices

This paper investigated the effect of flux activator used in reflow flux formulation on the electrochemical reliability of electronic devices. The focuses were placed on the perspective of surface insulation resistance (SIR), cleanliness, and its morphology transformation and redistribution behavior of flux residue under climatic exposure. Standardized accelerated climatic test on SIR comb-structure pattern was performed to benchmark the humidity interaction of the tested flux formulations used in solder paste. The influence of stand-off height for the surface-mount component on the humidity robustness was analyzed using an in-house designed dummy test rig and electrochemical impedance spectroscopy. Scanning electron microscopy and conductivity measurement was used to understand the hydrolytic degradation of the flux residue and the release of the conductive ionic residues during climatic exposure. Results indicate the spreading area and the hydrolytic degradation behavior of the flux residue were influenced by the type of flux activators used in flux formulation. The climatic reliability was influenced by the combined effect of the aggressiveness of flux activator and the spreading of the flux residue. However, result also shows that the climatic reliability of the surface-mount device can be improved by increasing the stand-off height of the components together with selected flux formulation.

A Contribution to Printed Circuit Boards' Miniaturization by the Vertical Embedding of Passive Components

Abstract This study describes a novel and unconventional approach for embedding passive surface mounted device (SMD) components into printed circuit boards. Therefore, passive components whose package size is 0201 are embedded in two types of vias. On the final quality of an embedded passive component, the effects of various technological factors, including tin-lead and lead-free solder pastes, various types and dimensions of vias, various soldering techniques, and sample positions during the reflow process, have been investigated and described. The results show the impact of tin-lead solder paste and polymeric solder paste on the creation of electrical shorts in the embedding of passive components. The application of microvias for the embedding of passive components eliminates the fundamental issues, such as electrical shorts, component dislocation, and the low success rate for creating a reliable solder joint. The proposed method for miniaturizing printed circuit boards by embedding passive components in microvias was verified by experimental results. The reliability of the proposed methodology is further supported by electrical measurements. This study describes an approach suitable to printed circuit board (PCB) prototyping that makes a negligible contribution to hardware design and electronic technologies.

Multimaterial Printing of Liquid Crystal Elastomers with Integrated Stretchable Electronics.

Liquid crystal elastomers (LCEs) have grown in popularity in recent years as a stimuli-responsive material for soft actuators and shape reconfigurable structures. To make these material systems electrically responsive, they must be integrated with soft conductive materials that match the compliance and deformability of the LCE. This study introduces a design and manufacturing methodology for combining direct ink write (DIW) 3D printing of soft, stretchable conductive inks with DIW-based "4D printing" of LCE to create fully integrated, electrically responsive, shape programmable matter. The conductive ink is composed of a soft thermoplastic elastomer, a liquid metal alloy (eutectic gallium indium, EGaIn), and silver flakes, exhibiting both high stretchability and conductivity (order of 105 S m-1). Empirical tuning of the LCE printing parameters gives rise to a smooth surface (<10 μm) for patterning the conductive ink with controlled trace dimensions. This multimaterial printing method is used to create shape reconfigurable LCE devices with on-demand circuit patterning that could otherwise not be easily fabricated through traditional means, such as an LCE bending actuator able to blink a Morse code signal and an LCE crawler with an on/off photoresistor controller. In contrast to existing fabrication methodologies, the inclusion of the conductive ink allows for stable power delivery to surface mount devices and Joule heating traces in a highly dynamic LCE system. This digital fabrication approach can be leveraged to push LCE actuators closer to becoming functional devices, such as shape programmable antennas and actuators with integrated sensing.

Connecting surface-mounted electronic elements with amber strand metal-clad conductive fibers by reflow soldering

Electronic yarns contain electronic components which are fully embedded into the conductive yarn’s structure before manufacturing smart textile garments or fabrics. To accept comprehensively the electronic textiles, it is essential to integrate the electronic components into/onto the conductive textile yarn without compromising the quality of the textile substrate. Therefore, one of the solutions is to create flexible and stretchable conductive yarn that contains a small surface-mounted electronic component embedded in the fibers of the conductive yarn. The purpose of this research work is to manufacture and subsequently evaluate the physical and electromechanical properties of amber strand (Toyobo’s p-phenylene benzobisoxazole fiber zylon) yarns with embedded surface-mounted device components. Using a benchtop reflow-soldering machine, the surface-mounted device component was successfully inserted into the amber strand conductive yarn. Then the developed electronic yarn was coated using thermoplastic polyurethane for encapsulation purposes. Furthermore, reliability tests of the electrical and mechanical properties of the electronic yarn (tensile strain and washing) were carried out. From the results it can be seen that the developed thermoplastic polyurethane encapsulated electronic yarn had a tensile strength of 37.38 N with a 4.1 mm extension. Furthermore, the relationship between the strain and washing action on the electrical resistance of the developed electronic yarn was experimentally investigated. The analytical finding shows that mechanical stress and laundry washing had a significant influence on the electrical resistance of the electronic yarn.

Three-Mode Variable-Frequency ZVS Modulation for Four-Switch Buck+Boost Converters With Ultra-High Efficiency

This article introduces a three-mode variable-frequency zero-voltage switching (ZVS) modulation method for the four-switch buck+boost converter. This method makes this circuit concept well suited for applications, such as wireless power charging of electric vehicles, where this circuit operates as a power buffer between the resonant converter and the battery with the function to implement the required charging profile. Herein, the buck+boost converter operation is subdivided into three operating regions according to the converter static voltage gain, i.e., buck-, buck-boost- and boost-type modes. A ZVS turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> triangular current mode (TCM) control is adopted for buck-type and boost-type modes. In the buck-boost-type mode when the input-to-output voltage gain is close to unit, all the possible modulation cases are studied thoroughly based on the phase shift of the two half bridges in a full switching period. The selection of the most suitable modulation scheme is performed to minimize the rms value of the inductor current while taking into account the simplification of the practical implementation. Closed-form equations are derived, which makes it easy to implement in practice. The proposed strategy is described, analyzed, and finally verified through a 3 kW surface mounted device (SMD) silicon carbide (SiC) <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> -based laboratory prototype with designed input voltage of 300–600 V and the typical output voltage of 400 V class battery. The efficiency from the measured results is remarkably high, i.e., between 99.2% and 99.6% in a power range from 1 to 3 kW. Finally, tests for the operating mode transitions demonstrated the feasibility of the proposed modulation method. The power density of this converter is 4.86 kW/L.

High-pass negative group delay analysis of single capacitor three-port circuit

PurposeThis paper aims to develop high-pass (HP) negative group delay (NGD) investigation based on three-port lumped circuit. The main particularity of the proposed three-port passive topology is the consideration of only a single circuit element represented by a capacitor.Design/methodology/approachThe methodology of the paper is to consider the S-matrix equivalent model derived from admittance matrix approach. So, an S-matrix equivalent model of a three-port circuit topology is established from admittance matrix approach. The frequency-dependent basic expressions are explored to perform the HP-NGD analysis. Then, the existence condition of HP-NGD function type is analytically demonstrated. The specific characteristics and synthesis equations of HP-NGD circuit with respect to the desired optimal NGD value are established.FindingsAfter computing the frequency expressions to perform the HP-NGD analysis, this study demonstrated the existence condition of HP-NGD function type analytically. The validity of the HP-NGD theory is verified by a prototype of three-port circuit. The proof-of-concept (POC) single capacitor three-port circuit presents an NGD response and characteristics from analytical calculation and simulation is in very good correlation.Originality/valueAn innovative theory of HP-NGD three-port circuit is studied. The proposed HP-NGD topology is constituted by only a single capacitor. After the topological description, the S-matrix model is established from the Y-matrix by means of Kirchhoff voltage law and Kirchhoff current law equations. A POC of single capacitor three-port circuit was designed and simulated with a commercial tool. Then, a prototype with a surface-mounted device component was fabricated and tested. As expected, simulation and measurement results in very good agreement with the calculated model show the feasibility of the HP-NGD behavior. This work is compared to other NGD-type function with diverse number of ports and components.

Design of a Low Cost X-Band LNA with Sub-1-dB NF for SATCOM Applications

In this article, we demonstrate a low-cost 7.25-7.75 GHz two-stage low noise amplifier with sub-1-dB noise figure for satellite communication applications. The microstrip technology on Rogers RT5880 substrate with the dielectric constant of 2.2 and thickness of 0.508 mm were utilized to develop a low noise amplifier. The printed-circuit-board technology offers a variety of profits such as being low-cost, lighter-weight and re-configurability after the manufacturing process make this technology charming for satellite communication systems for both commercial and military applications. Since the monolithic microwave integrate circuit technology provide much smaller sized circuits and high electrical performance especially at the millimeter-wave frequencies, the printed microstrip technology can be a significant rival to integrated-circuit technology with its proven reliability, easier, cheaper and faster manufacturing process, compactible electrical performance in X-band applications. Moreover, the proposed amplifier was developed with utilizing California Eastern Laboratories’ CE3512K2 transistor on Rogers-RT5880 and surface mount devices were utilized in the matching networks to reduce the size. In addition, the source-generation and interstage matching topologies were implemented to simplify the matching complexity to enhance the noise and gain. The prototype was manufactured with utilizing LPKF prototyping machine. The developed LNA exhibits a measured gain of 23.5±0.5 dB with the noise figure of less than 0.9 dB and input/output return loss better than 11.5 dB in the operating frequency bandwidth. Furthermore, the developed amplifier has a measured carrier to interference of -59 dBc and P1dB of 13 dBm at the center frequency while consuming a total DC power of 50 mW.

Flexible Hybrid Electronics via Near‐Infrared Radiation‐Assisted Soldering of Surface Mount Devices on Screen Printed Circuits

AbstractThe development of flexible hybrid electronics (FHEs) with high‐throughput integration of electrical components onto digitally printed circuits has a wide range of applications, such as asset tracking, wearable electronics, and structural health monitoring. However, one of the major challenges with FHEs is the process of soldering the electrical components onto a printed circuit while having minimal thermal damage to the printed traces and their temperature‐sensitive polymeric substrates. Here, the possibility of utilizing near‐infrared (NIR) technology as a nondestructive photonic approach for rapid soldering and mounting electrical components onto printed circuits while keeping the polymer substrate at a relatively low temperature during the soldering process is investigated. Results of this systematic study show that FHEs prepared with the optimized NIR processing conditions produce the desired reflow of solder with effective electrical connection and metallic bonding of electrical components onto the conductive traces with excellent mechanical stability (no failure even after 1000 cycles of bending). Furthermore, using this technique and as a proof of concept, the fabrication of a wearable FHE device that provides a remote assessment of the wound exudate absorption in dressings and notifies caregivers of the appropriate time to change the dressing is demonstrated.

우수-기수 모드 해석을 통한 표면 실장 소자의 기생 성분 계산 방법

This paper presents a method for calculating the parasitic component of surface-mounted devices (SMD) on a printed circuit board (PCB) using even-odd mode analysis. The paper addresses the discrepancy between simulation results and measurements when designing high-frequency circuits using PCB and SMD. The cause of this difference is attributed to the significant impact of parasitic components between the PCB and SMD at high frequencies. Traditional simulation tuning is often time-consuming to identify these parasitic components, but this paper shows a simple even-odd mode analysis can effectively calculate them at the 3.7 GHz band.

Experimental study on thermal management of surface mount device–LED chips towards applicability in a headlamp of modern cars

This paper describes an experimental study of the thermal performance of SMD-LED chips (surface mount device – light-emitting diodes) in modern car headlamps. For this purpose, a new test model is proposed for the first time. The effect of key parameters, such as LED powers, ambient temperatures outside the headlamp, chamber configurations with and without inner lens, and heat sink (HS) sizes, is examined. As a result, a correlation between the mean air temperature (MAT) and the key parameters is essentially revealed. Variation of MAT with the LED power supply obeys the power law regardless of the presence of the inner lens. Moreover, it is also extremely complicated and depends on many effects. The thermal resistance decreases with increasing the HS size or decreasing the volume ratio of the housing chamber to HS (Vr). A significant reduction in thermal resistance and MAT per unit of HS area is up to 67.7 % and 74 % when Vr is reduced from 64.5 to 15.8, respectively. Based on these results, a new approach to thermal management of an enclosed chamber can be developed prospectively by defining the ambient temperature as MAT.

Process Development for Printed Copper With Surface Mount Devices on Inkjet Metallization

Abstract Printed electronics is a fastest growing and emerging technology that have shown much potential in several industries including automotive, wearables, healthcare, and aerospace. Its applications can be found not only in flexible but also in large area electronics. The technology provides an effective and convenient method to additively deposit conductive and insulating materials on any type of substrate. Despite its status, it is not without its challenges. Inkjet technology has gained much attention due to its low cost, low-material consumption, and capability for mass manufacturing. The preferred conductive metal of choice has been mostly silver due to its excellent electrical properties and ease in sintering. However, silver comes to be expensive than its counterpart copper. Since copper is prone to oxidation, much focus has been given toward photonic sintering that involves sudden burst of pulsed light at certain energy to sinter the copper nanoparticles. With this technique, only the printed material gets sintered in a matter of seconds without having a great impact on its substrate. With all the knowledge, there is still a large gap in the process side with copper where it is important to look how the print process affects the electrical and mechanical properties of copper. With the process developed, the resistivity of printed copper was found to be five times the bulk copper. In regards to adhesion to the polyimide film, mechanical shear load to failure was found to be within 15–20 gF. To demonstrate the complete process, commercial-off-the-shelf components are also mounted on the additively printed pads. Statistically, control charting technique is implemented to understand any process variation over long duration of prints.

The Fe79Si8B13 and Fe75Si8B13Nb3Cu1 powder prepared by gas-water two-phase coupled rapid-setting sedimentation atomization (WGC)

To satisfy the reliability and magnetic property requirements of surface mounted devices (SMD), the high-performance Fe79Si8B13 and Fe75S8iB13Nb3Cu1 powders were prepared by gas-water two-phase coupled rapid-setting sedimentation atomisation technology (WGC). They were compared with the Fe79Si8B13 and Fe75S8iB13Nb3Cu1 powders prepared by the traditional water-gas combined atomisation technology (W-G). The result shows that the morphology of the Fe79Si8B13 and Fe75S8iB13Nb3Cu1 powders prepared by the WGC device is better. The defects, such as burrs and protrusions on the surface of powder particles, were removed, and the formed powders were almost entirely spherical. Through x-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and vibrating sample magnetometer (VSM) analyses, we concluded that the Fe79Si8B13 and Fe75S8iB13Nb3Cu1 raw powder developed by the WGC device exhibited higher amorphousness and magnetic properties. Therefore, the novel WGC device exhibits a higher cooling capacity while preparing amorphous and nanocrystalline powders. It is also more suitable for the commercial production of amorphous and nanocrystalline powders. The magnetic properties of the powder were further evaluated by preparing them into a powder core. The powder developed by the WGC device with higher permeability can achieve similar direct current (DC) bias characteristics under higher permeability and lower core losses. These advantages of magnetic properties were pursued via SMD.

Towards virtually optimized curing cycles for polymeric encapsulations in microelectronics

Surface Mounted Devices (SMDs) are widely used throughout microelectronics and power electronics. They mostly employ epoxy molding compound (EMC) based encapsulations. Thus, enhanced lifetime assessment methods are necessary. To understand the stress situation in SMDs at the end of the production cycle, an improved model approach for the curing of EMC is implemented within Finite Element Analysis (FEA) simulations. During production, e.g., in a Resin Transfer Molding (RTM) process, material properties are spatially varying due to different curing degrees. Hence, a mismatch of mechanical properties is present, which in return leads to internal stresses. The introduced model approach is an extension of the work of Gschwandl et al. (2017) and includes a stress-free deformation before vitrification, changing material properties during curing, as well as plastic deformations and visco-elastic effects. The implementation in numerical FEA simulations allows for a better understanding of arising residual stresses and helps optimize the production cycle of SMDs.

3D printed optical sensor for highly sensitive detection of picric acid using perovskite nanocrystals and mechanism of photo-electron transfer

Hand-held, compact and portable sensors for on-site detection of environmental contaminants are in high demand for industry 4.0. Here, we have developed a sensor based on luminescent organic–inorganic metal halide hybrid perovskites nanocrystals (CH3NH3PbBr3) with p-xylylenediamine as an additional capping agent for highly sensitive and selective detection of picric acid (PA), with a good linear range of 1.8 μM–14.3 μM achieving detection of limit (LOD) of 0.3 μM. The electrostatic interaction between PA and the capping ligand of perovskite nanocrystals resulted in significant fluorescence quenching, as revealed by the steady-state and time-resolved spectroscopy. The applicability of the developed sensor for PA detection was validated with a 3D printed device integrating surface mounting device (SMD) and paper microfluidics. This prototype device was successfully applied as a fluorescence turn-off sensor to detect PA, showing great potential for on-site detection. This 3D-printed paper-based microfluidic optical sensor proved very efficient for naked-eye detection of PA with an inbuilt excitation source, avoiding the requirement of expensive and complex instrumentation.

VitRad: A low-cost continuous wave Doppler radar system with 3D-printed horn antennas for human vital sign detection

In this study, a low-cost continuous wave (CW) radar system with 3D-printed high-gain horn antennas called VitRad is proposed for human vital sign detection. The CW radar consists of 3D-printed high-gain horn antennas, commercially available low-cost surface-mounting devices, and monolithic ICs. The CW radar system operates at a frequency band of 5.8 GHz, and the backscattered I/Q data are collected using a digital storage oscilloscope (DSO). The data is processed on MATLAB to determine vital sign information such as respiratory and heartbeat rates. It is demonstrated that the proposed CW radar system for vital-sign monitoring can effectively measure respiratory and heartbeat rates.

Cost-Effective Surface-Mount Magnetoelectric Dipole Antenna Based on Ball Grid Array Packaging Technology for 5G Millimeter-Wave New Radio Band Applications

This article presents a cost-effective miniature surface-mount magnetoelectric (ME) dipole antenna. The antenna is realized by a single-layer FR4 substrate and combined with ball grid array (BGA) packaging technology to achieve miniaturization in size. Due to BGA packaging technology, the surface-mount capability allows interconnection between the proposed antenna and other surface-mount devices using a flip-chip interconnect technology, replacing bulky connectors. The proposed antenna element is very compact. Specifically, the electric dipole of the proposed antenna consists of four patches, whereas the magnetic dipole consists of two rows of plated through-holes and a metal ground between them. In addition, the electric and magnetic dipoles are simultaneously excited by an L-shaped metal probe. The prototype has been manufactured and carefully verified. Experimental results show that the proposed antenna element has a −10-dB bandwidth of 23% in the range of 25–31.5 GHz and achieves a peak realized gain of 6.98 dBi at 26 GHz. The dimensions of the proposed antenna element are only 5 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 5 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times1.8$ </tex-math></inline-formula> mm. The proposed antenna elements can be widely used in the 5G millimeter-wave N257 (26.5–29.5 GHz) and N261 (27.5–28.35 GHz) bands.