Mount Devices Research Articles

Soldering surface mount components on screen-printed Ag patterns on paper and polyimide substrates for hybrid printed electronics

The development of printed electronics on flexible substrates is increasing rapidly, where the main benefits are the large area and low cost. However, the functionality and performance of printed circuits cannot compete with standard silicon based microprocessors or integrated circuits, though the functionality and performance of printed circuits are increasing. Therefore, in this work we investigate the possibilities of using Sn42/Bi57.6/Ag0.4 low-temperature solder paste together with a reflow solder oven and hot air solder iron to mount regular surface mount device (SMD) components on screen-printed silver tracks. It was found that it is possible to solder standard Si SMD packages onto screen-printed Ag ink tracks on paper substrate; however, the component bonding strength to polyimide was not satisfactory. The resistance of the solder joints was found to be no more than 240 mΩ. The bond strength was found to be higher using the manual hot air solder iron than the reflow solder oven. Bending tests show that the bonding strength is higher for the hot air soldered components. Reference samples on FR-4 based copper printed circuit board show a bond strength ∼10 times higher but we conclude that it is possible to solder regular Si SMD components onto Ag-printed conductors on paper substrate with good results. The process could be used to fabricate hybrid printed electronics in a standard solder process line.

A power device material of corundum-structured α-Ga2O3 fabricated by MIST EPITAXY® technique

Corundum-structured oxides have been attracting much attention as next-generation power device materials. A corundum-structured α-Ga2O3 successfully demonstrated power device operations of Schottky barrier diodes (SBDs) with the lowest on-resistance of 0.1 mΩ cm2. The SBDs as a mounting device of TO220 also showed low switching-loss properties with a capacitance of 130 pF. Moreover, the thermal resistance was 13.9 °C/W, which is comparable to that of the SiC TO220 device (12.5 °C/W). On the other hand, corundum-structured α-(Rh,Ga)2O3 showed p-type conductivity, which was confirmed by Hall effect measurements. The Hall coefficient, carrier density, and mobility were 8.22 cm3/C, 7.6 × 1017/cm3, and 1.0 cm2 V−1 s−1, respectively. These values were acceptable for the p-type layer of pn diodes based on α-Ga2O3.

Numerical Calculation and Analysis on the Surface Electric Field Characteristics of Hot-Line Robot

Hot-Line robot (HLR) is an automatic transmission line inspection device developed in recent years. The mounting device should be contacted with the high voltage transmission line thus to realize the voltage transfer at the first operation stage of the HLR, and the HLR device which is regarded as a floating electrode might be damaged by discharge induced by the filed distortion during the voltage transfer process. The surface electric field of HLR device is optimized to improve its operation reliability, and a static-electric field finite element model of the transmission line which includes the HLR device is developed in this paper, and the dynamic surface electric filed characteristics of HLR during elevating operation process are studied by the finite elements model. Results show that influenced by the electric field which induced by high-voltage transmission line, the induced electric field can be generated on the surface of HLR during the process of elevating operation. The induced electric field distorts on the edge chamfer of HLR device which is regarded as a floating electrode. The maximum field strength position is influenced by the arrangement of the overhead wire conductor, and the edge chamfers are the key points of the electric field optimization of the HLR. The results of this study could provide theoretical basis and technical support for the optimization of HLR insulation characteristics, which is of great value to improve its operation reliability.

Solder joint quality evaluation based on heating factor

PurposeThe purpose of this paper is to increase the reliability of manufactured electronics and to reveal reliability significant factors. The experiments were focused especially on the influence of the reflow oven parameters presented by a heating factor.Design/methodology/approachThe shear strength of the surface mount device (SMD) resistors and their joint resistance were analyzed. The resistors were assembled with two Sn/Ag/Cu-based and one Bi-based solder pastes, and the analysis was done for several values of the heating factor and before and after isothermal aging. The measurement of thickness of intermetallic compounds was conducted on the micro-sections of the solder joints.FindingsThe shear strength of solder joints based on the Sn/Ag/Cu-based solder alloy started to decline after the heating factor reached the value of 500 s · K, whereas the shear strength of the solder alloy based on the Bi alloy (in the measured range) always increased with an increase in the heating factor. Also, the Bi-based solder joints showed shear strength increase after isothermal aging in contrast to Sn/Ag/Cu-based solder joints, which showed shear strength decrease.Originality/valueThe interpretation of the results of such a comprehensive measurement leads to a better understanding of the mutual relation between reliability and other technological parameters such as solder alloy type, surface finish and parameters of the soldering process.

Comparison of lipid extraction methods for the microalgae Acutodesmus obliquus

Microalgae are widely used in the pharmaceutical and energy industries, therefore the conditions for their cultivation and extraction methods play an important role in the profiling and acquisition of lipids. The efficiency of lipid extraction from microalgae has attracted great interest from industry because of the wide variety of lipids and amounts that can be obtained. Acutodesmus obliquus (Scenedesmus obliquus UTEX 393) was used in this study. It was cultivated in Bold 3N medium modified with 75% nitrogen at 25°C, pH 6.8, 125 r/min and a photoperiod of 18/6 h and illuminated with white light provided by a Light-Emitting Diode Surface Mount Device extensions (LED SMD) with an intensity of 1200 µE/(m2•s). The cells were stained with the Red Nile (RN) technique to indicate lipid production. Four extraction methods were compared, classical, microwave (MW), Soxhlet, and ultrasound (US), using the same solvent proportions (hexane: chloroform: methanol=1:2:3). All samples were analyzed with Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography coupled to Mass Spectrometry (GC-MS). The results showed: 1) lipid production detected by RN was consistent with microalgal growth; 2) the MW technique was the best extraction method, according to the statistical analysis through Randomized Complete Block (RCB) design and performance of 4.6%; and 3) the presence of saturated and unsaturated acids was indicated by FTIR spectra. GC-MS was able to identify palmitic and linoleic acids as the likely major constituents of the sample. Keywords: Acutodesmus obliquus, lipid extraction, trans-esterification, Red Nile (RN) DOI: 10.25165/j.ijabe.20181105.3748 Citation: Hurtado D X, Garzón-Castro C L, Cortés-Romero J, Tello E. Comparison of lipid extraction methods for the microalgae Acutodesmus obliquus. Int J Agric & Biol Eng, 2018; 11(5): 211–217.

Feature Extraction and Template Matching Algorithms Classification for PCB Fiducial Verification

Automatic Optical Inspection (AOI) systems that are extensively used in the industry of Electronics Manufacturing Services (EMS), performs the inspection of Surface Mount Devices (SMD). One of the main tasks of such an AOI system is to align a given PCB to the parameters of the corresponding PCB positioning system by a process called fiducial alignment. However, no detailed analysis has been carried out so far on the methodologies that can be used to have a very precise identification of PCB fiducial points. In our research, we have implemented an AOI system for the inspection of soldering defects of Through Hole Technology (THT) solder joints, which can be integrated to a desktop soldering robotic platform. Such platforms are used in environments where no specific lighting conditions can be provided within a surrounded atmosphere. Therefore, an AOI system that is capable of performing fiducial alignment of any given PCB under varying lighting condition is highly preferred. In this paper, we have presented a detailed analysis on feature extraction and template matching algorithms that can be used to implement a very precise fiducial verification process under normal lighting condition.

Open Source Automated SMD Pick and Place Machine

Surface Mount Device (SMD) is widely used in an automated Printed Circuit Board (PCB) assembling plant. Soldering SMD is a tedious and time-consuming process when it is done using bare hands. Industries require bulk production and hence it cannot be achieved by manual labour. For this fully automated SMD Pick and Place (P&P) machines are available in the market but the cheapest one starts at INR 15 Lakh (Yamaha yv-100x—Refurbished) and they are proprietary. Start-ups especially India based, find it difficult to afford such machine. In this paper, this issue is addressed and built an automated SMD P&P machine which is open source and far cheaper than the cheapest one in the market. However, the algorithm of the developed SMD P&P Machine and the one in the market remains the same but it functions differently and the steps are as follows; (i) Component are loaded onto the feeder tray (ii) Centroid file( machine file in ASCII format which comprise reference designator, X, Y, rotation, top or bottom side of the PCB board) is fed to the machine (iii) From the feeder tray component is picked by placement head using vacuum suction (iv) If the component is available in the placement head then correcting of component’s orientation and alignment using image processing is done else placement head is made to re-pick the component from feeder tray (v) Properly aligned and oriented component is placed on the PCB by releasing the vacuum. The proposed model is open source in both hardware (Raspberry Pi & Arduino) and software which is user friendly and easy to customize as per requirements.

Irrigation Scheduling Using Soil Moisture Sensors

Irrigation is required to ensure crop production. Practical methods of use sensors to determine soil water status are needed in irrigation scheduling. Soil moisture sensors were evaluated and used for irrigation scheduling in humid region of the Mid-South US. Soil moisture sensors were installed in soil at depths of 15 cm, 30 cm, and 61 cm belowground. Soil volumetric water content was automatically measured by the sensors in a time interval of an hour during the crop growing season. Soil moisture data were wirelessly transferred onto internet through a wireless sensor network (WSN) so that the data could be remotely accessed online. Soil water content measured at the three depths were interpreted using a weighted average method to reflect the status of soil water in plant root zone. A threshold to trigger an irrigation event was determined with sensor-measured soil water content. An antenna mounting device was developed for operation of the WSN. Using the antenna mounting device, the soil moisture measurement was not be interrupted by crop field management practices.

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur.

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The amount of the different tissues in the callus provides important information on the fracture healing progress. Available in vivo techniques to longitudinally monitor the callus tissue development in preclinical fracture-healing studies using small animals include digital radiography and µCT imaging. However, both techniques are only able to distinguish between mineralized and non-mineralized tissue. Consequently, it is impossible to discriminate cartilage from fibrous tissue. In contrast, magnetic resonance imaging (MRI) visualizes anatomical structures based on their water content and might therefore be able to noninvasively identify soft tissue and cartilage in the fracture callus. Here, we report the use of an MRI-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice. The experiments demonstrated that the fixator and a custom-made mounting device allow repetitive MRI scans, thus enabling longitudinal analysis of fracture-callus tissue development.

Mounting of Biomaterials for Use in Ophthalmic Cell Therapies

When used as scaffolds for cell therapies, biomaterials often present basic handling and logistical problems for scientists and surgeons alike. The quest for an appropriate mounting device for biomaterials is therefore a significant and common problem. In this review, we provide a detailed overview of the factors to consider when choosing an appropriate mounting device including those experienced during cell culture, quality assurance, and surgery. By way of example, we draw upon our combined experience in developing epithelial cell therapies for the treatment of eye diseases. We discuss commercially available options for achieving required goals and provide a detailed analysis of 4 experimental designs developed within our respective laboratories in Australia, the United Kingdom, and Belgium.

A Compact Analog Complex Cross-Correlator for Passive Millimeter-Wave Imager

The design, analysis, implementation, and measurement of a compact analog complex cross-correlator for passive millimeter-wave imaging applications are presented in this paper. The correlator uses the “add and square” and “subtract and square” detection scheme by adopting the Schottky diodes and RF distribution network. Meanwhile, in order to realize the correlator with a compact size and low cost, commercially available surface mounting devices and multilayer PCB technique are employed. The relationship between the phase error of the correlator and the phase unbalance of the RF distribution network is also analyzed. Single-frequency test is applied to the correlator, and the results of the measurement reveal that the correlator operates well within the frequency range of 1.5–2.5 GHz. Moreover, a measurement system based on an actual imaging scenario is also developed to characterize the performance of the correlator when injected with correlated broadband noise signals, and the measurement results show that the correlator is well suited for imaging applications. The bandwidth of the current version correlator is around 1 GHz, but it could easily be changed by replacing distributed components.

Practical Application and Analysis of Lead-Free Solder on Chip-On-Flip-Chip SiP for Hearing Aids

Abstract Due to rapid growth of the microelectronics industry, packaged devices with small form factors, low costs, high power performance, and increased efficiency have become of high demand in the market. To realize the current market development trend, flip chip interconnection and System-in-Package (SiP) are some of the promising packaging solutions developed. However, a surprising amount of surface mount technology (SMT) defects are associated with the use of lead-free solder paste and methods by which the paste is applied. Two such defects are solder extrusion and tombstoning. Considerable amount of defects associated with solder overflow are found on chip-on-flip-chip (COFC) SiP in hearing aids. Through the use of design of experiments (DOE), lead-free solder defect causes on hearing aids application can be better understood and subsequently reduced or eliminated. This paper will examine the failure modes of solder extrusion and tombstoning that occurred when two different types of lead-free solders, Sn-Ag-Cu (SAC) and BiAgX were used within a SiP for attachment of surface mount devices (SMD) chip components for hearing aid applications. The practical application and analysis of lead-free solder for hearing aids will include the comprehensive failure analysis of the SMD components and compare the modeling and analysis of the two different solder types through the DOE process.

Effect of a New Bleaching Gel on Tooth Whitening.

The purpose of this study was to compare the whitening efficacy of a novel bleaching agent containing a unique tribarrel hydremide-peroxide gel (KöR) with a traditional bleaching system of hydrogen peroxide or carbamide peroxide (Opalescence). Bovine incisors were mounted into a custom resin, arch-shaped mounting device. Four groups of 10 teeth were created using mounting devices containing five teeth each. The in-office and home bleaching gels of KöR and Opalescence were applied to the teeth alone and in trays to simulate a combination of in-office and home bleaching or home bleaching only. Spectrophotometer readings of L* a* b* were performed at baseline, the end of active bleaching (immediate), and three and six months postbleaching. Immediately postbleaching, the use of Opalescence gel resulted in greater change in ΔE* and Δb* (less yellow) for combined and home bleaching techniques compared with KöR. After six months, Opalescence had significantly greater ΔE* and Δb* compared with KöR for home bleaching only. There was no significant difference in ΔL* between Opalescence and KöR at any time period with either technique.

Package-Level Reconfiguration of RF Matching Networks Using SMD Components

Digital power amplifiers provide an unprecedented level of flexibility in their ability to operate on different signals using simple reprogramming of the digital signal processing, but their output matching networks must be redesigned for different frequency bands. This involves a redesign of part of the back-end-of-line mask set at a great cost. We present a package-level reconfiguration technique that allows a single transmitter to be reconfigured for multiple frequency bands, or different output power levels by soldering different surface mount device (SMD) components directly to the surface of the die, saving design and fabrication cost while delivering similar performance. We demonstrate the technique on a multiphase transmitter IC, showing optimized operation at three different frequencies using soldered SMD components to reconfigure the matching network of the IC at the package level. The transmitter’s linearity and performance are validated using a 5-MHz, 64-QAM LTE signal.

Localization of component lead inside a THT solder joint for solder defects classification

Purpose: Automatic Optical Inspection (AOI) systems, used in electronics industry have been primarily developed to inspect soldering defects of Surface Mount Devices (SMD) on a Printed Circuit Board (PCB). However, no commercially available AOI system exists that can be integrated to a desktop soldering robotic system, which is capable of identifying soldering defects of Through Hole Technology (THT) solder joints along with the soldering process. In our research, we have implemented an AOI platform that is capable of performing automatic quality assurance of THT solder joints in a much efficient way. In this paper, we have presented a novel approach to identify soldering defects of THT solder joints, based on the location of THT component lead top. This paper presents the methodologies that can be used to precisely identify and localize THT component lead inside a solder joint. Design/methodology/approach: We have discussed the importance of lead top localization and presented a detailed description on the methodologies that can be used to precisely segment and localize THT lead top inside the solder joint. Findings: It could be observed that the precise localization of THT lead top makes the soldering quality assurance process more accurate. A combination of template matching algorithms and colour model transformation provide the most accurate outcome in localizing the component lead top inside solder joint, according to the analysis carried out in this paper. Research limitations/implications: When the component lead top is fully covered by the soldering, the implemented methodologies will not be able to identify the actual location of it. In such a case, if the segmented and detected lead top locations are different, a decision is made based on the direction in which the solder iron tip touches the solder pad. Practical implications: The methodologies presented in this paper can be effectively used to have a precise localization of component lead top inside the solder joint. The precise identification of component lead top leads to have a very precise quality assurance capability to the implemented AOI system. Originality/value: This research proposes a novel approach to identify soldering defects of THT solder joints in a much efficient way based on the component lead top. The value of this paper is quite high, since we have taken all the possibilities that may appear on a solder joint in a practical environment.

3D Metamorphic Stretchable Microphone Arrays

AbstractThis article describes the realization of a metamorphic microphone array. The array morphs from a concave to a planar and then to a convex shape. The morphing array enables a better (12×) sound source localization when compared to existing static and planar arrangements. To enable the realization, a novel stretchable (elongated up to 320% of the original length) printed circuit board fabrication process is reported. The fabrication process enables high‐temperature processing, alignment, and registration. Moreover, conventional and otherwise rigid surface mount devices (SMDs) can be used. The process allows the researcher to increase the number of devices (30 SMDs) and interconnects (60 in total) to the required level. As electrical connections, a polyimide‐cladded metal track design is reported; the design sustained 11 050 stretch and release cycles. Moreover, 3D reinforcement frames are reported as an effective measure to shield the SMD components from high levels of stress. The resulting products are millimeter‐thin stretchable rubber‐embedded and electrically interconnected electronic structures with mechanical rubber‐membrane‐like properties. Morphology changes involve deflation and inflation of the membrane to bulge inward or outward. Finally, the use of 3D‐shaped chaperon is discussed to provide additional shape control.

AC–DC Disk Resistors Made of Surface Mount Components

Disk resistors are widely used in micropotentiometers up to frequencies in the radio frequency range. They offer very small AC–DC differences but the permissible power dissipation is quite small. Also, the resistance value is poorly defined due to the lack of four-terminal connections. This can be overcome by newly designed disk resistors made of surface mount device components [1]. They are also well suited as AC–DC current shunts for currents up to several amperes.

Ballistic wearable electronic vest design

In present study, electronic vests were designed by using conductive textile material and electronic circuits. The objective was to sense armed assaults and transmit the coordinates and position of gun fire instantly to the headquarters. Another objective is to provide instant emergency respond for injuries at vital sections of the body and to capture perpetrators quickly. To reach the desired targets, silver-coated conductive yarn, polyamide plain weave and various circuit components were used. Silver-coated conductive yarn was used to form sensor unit of the electronic vest and stitched over polyamide fabric in 3 mm intervals. Main vest section was prepared in medium size and conductive-yarn sensor unit was installed to the vest with a velcro system. Classical and Surface Mount Device (SMD) circuit technologies were used in circuit units to sense bullet intrusion and transmit the case to operational center. Two different circuit designs were tested at a shooting range and the outcomes were assessed and ...

Gulliver Prototype Development and Deployment

The current objective of our project is to develop a technology, coined Gulliver, aimed at enhancing the study of microorganisms. This device will expand upon established in situ technology to cultivate and isolate microorganisms in one step. Our long term goal is for this device is to not only isolate and culture in one step, but also to eventually equip our device with nanosensors to allow in situ monitoring of bacterial growth and activity, and transmit this data directly to the researcher, allowing an unprecedented view into the microbial world. The Gulliver design consists of a flat mounting device with a 4 mm hole in the center to act as the growth chamber. On one side of the device, a polycarbonate membrane with 0.03μm pores is attached, allowing for diffusion of nutrients and growth signals from the environment. On the reverse side, the same membrane is affixed, however it contains an approximately 1 μm entry aperture, to allow entry of a single microbial cell into the growth chamber. Once the microorganism enters the pore, the entrance is blocked. As the organism continues to grow and divide, it is provided with nutrients from the environment through the diffusion pores, and a pure colony will develop inside the device. After a period of in situ incubation, the device is removed from the environment, the growing biomass retrieved from the growth chamber, “domesticated” and grown on a petri dish for further study. Currently, testing is underway using fluorescently labeled bacterial species to prove the concept of autonomous cultivation and isolation in on step. Devices will be incubated in mixed cultures of fluorescently labeled bacteria, and growth will be collected from each chamber. Fluorescence will be used to ensure a pure culture is obtained. Thus far, we have demonstrated an ability to reliably produce 1 μm pores in polycarbonate membrane. Furthermore, we have designed a prototype of the device consisting of the polycarbonate membrane adhered to a silicone or PTFE base. The prototype is capable of withstanding incubation in an aqueous environment, without material degradation, for up to 3 months, providing an extended period of time for environmental study of microorganisms. The overall goal of this project is to gain a fuller picture of the microbial world, allowing researchers to access novel microorganisms, study the important environmental processes they perform, and utilize the valuable bioactive compounds they produce.Support or Funding InformationThis particular segment of the project is supported by the NSF, the Alpha Fund Grant, and an Northeastern Undergraduate Research and Creative Endeavors Award.

APLIKASI PERHITUNGAN KAPASITOR SURFACE MOUNT DEVICE

Calculate the capacitor by utilizing the technology will become more enjoyable and easier than counting capacitor using analog avometer. Calculating the capacitor will be easy fun and more interesting if we calculate it using the applications in the gadget that is growing rapidly at this time, especially android. Applications capacitor calculation Surface Mount Device android-based using java language and compiler software as the eclipse. There are three types of calculators capacitors, including two standard calculator ventax place code, calculator samsung alternate two code numbers and calculator samsung standard single place code. Design system used there are four, namely: Activity Diagram, Usecase Diagram, Sequence Diagram, and Deployment diagrams. The fourth component is part of the UML (Unified Modeling Language).