Surface Mount Devices Research Articles

Current-Voltage Response of Cold White LED Strip to Radiotherapeutic Electron and Photon Beams: A Preliminary Study

Photonic devices such as photodiodes, phototransistors, solar cells, and charge-coupled devices (CCDs) have been associated with clinical radiation detection in recent studies. Light Emitting Diodes (LEDs) are of low-cost in comparison to photodiodes and available in various flexible designs, including surface mount devices (SMDs). LEDs are purposely designed to emit light, but they can also be implemented for detecting light in a photovoltaic mode. Despite the LED-related merits, a few studies, compared to other photonic devices, especially photodiodes, have adopted them as medical radiation detectors. This research hence exploits the LED’s dual applicability by investigating a cold/cool white LED strip current-voltage (C-V) signal response to photon and electron beams. Radiation parameters such as beam energy, angle of incidence, field size, surface source distance (SSD), and monitor units (prescribed dose) were varied. According to the obtained results, the electron beams induced a 10% higher C-V signal compared to photon beams. An angular dependence was also observed, i.e., the C-V signal fluctuated due to a variation in the irradiation angles; -45°, -25°, 0°, 25°, 45°, and radiation type – photon and electron beams. The C-V signal response to SSD alterations additionally produced bimodal signal graphs, skewed towards shorter SSDs, for all the beams used in this study. Finally, the C-V signal was generally linear to the prescribed dose for both the photon and electron beams. Overall, the response of LEDs to photon and electron beams separately exhibited a similar signal trend for the beam energy, field size, angular dependence, and SSD parameter variations. On the other hand, dose linearity produced contrasting signal trends across the photon and electron beams.

Printed Smart Devices on Cellulose-Based Materials by means of Aerosol-Jet Printing and Photonic Curing.

Printed electronics is an expanding research field that can reach the goal of reducing the environmental impact on electronics exploiting renewable and biodegradable materials, like paper. In our work, we designed and tested a new method for fabricating hybrid smart devices on cellulose substrates by aerosol jet printing (AJP) and photonic curing, also known as flash lamp annealing (FLA), capable to cure low temperature materials without any damage. Three different cellulose-based materials (chromatographic paper, photopaper, cardboard) were tested. Multilayer capability and SMDs (surface mount devices) interconnections are possible permitting high flexibility in the fabrication process. Electrical and geometrical tests were performed to analyze the behavior of printed samples. Resulted resistivities are 26.3 × 10−8 Ω⋅m on chromatographic paper, 22.3 × 10−8 Ω⋅m on photopaper and 13.1 × 10−8 Ω⋅m on cardboard. Profilometer and optical microscope evaluations were performed to state deposition quality and penetration of the ink in cellulose materials (thicknesses equal to 24.9, 28.5, and 51 μm respectively for chromatographic paper, photopaper, and cardboard). Furthermore, bending (only chromatographic paper did not reach the break-up) and damp environment tests (no significant variations in resistance) where performed. A final prototype of a complete functioning multilayer smart devices on cellulose 3D-substrate is shown, characterized by multilayers, capacitive sensors, SMDs interconnections.

Contactless pick-and-place of millimetric objects using inverted near-field acoustic levitation

We model and realize an ultrasonic contactless pick-and-place device capable of picking, self-centering, self-orienting, translating, and releasing flat millimetric objects. The device is an ultrasonic Langevin transducer operating at 21 kHz that radiates into air through a tapered tip. Objects are trapped few micrometers below the tip due to the near-field acoustic levitation phenomenon. We first investigate the conditions to achieve an attractive force on the object depending on its size and the device operating frequency. Second, we use a 3D acoustic model that describes the converging forces and torque that provide the self-centering and self-orienting capabilities. Third, a more advanced Computational Fluid Dynamics model based on the Navier–Stokes equations explains the small gap between the tip and the trapped object. The contactless manipulation capabilities of the device are demonstrated by picking, transporting, and releasing a Surface Mount Device in air. The presented manipulation concept can be an interesting alternative for manipulating delicate objects such as microelectromechanical devices, silicon dies, or micro-optical devices.

Improvement of Field Effect Capacity Type Gas Sensor Thermo Inertial Parameters by Using Laser Micromilling Technique

This paper presents a verification of technology aspects for improvement of field effect capacity type gas sensor parameters by using laser micromilling technique for fabrication ceramic surface mounting device (SMD) package and microheater for sustentation working temperature of metal-insulator-semiconductor structure (MIS structure). Innovative claims include: demonstration of flexible opportunities for new digital fabrication process flows based on laser micromilling tech: fast design of SMD sensor 3-D model, flexible changing topology of microheater, thick and thin film technology combination for reducing of power consumption. The results show possibility to fast fabrication functional sensor in customer ceramic SMD package with base 9x9 mm with twice reduced power consumption and improving mechanical properties compare with classical metal-glass microelectronic packages using before for such type sensors.

Parameter Studies of Ceramic MEMS Microhotplates Fabricated by Laser Micromilling Technology

This paper presents a modeling of technology aspects for fabrication ceramic microelectromechanical systems (MEMS) microhotplate and surface mounting device (SMD) packaging for (MOX) gas sensors applications. Innovative claims include: demonstration of flexible opportunities for new fabrication process flows based on laser micromilling tech; modeling of power consumption MEMS microhotplate depending on the thickness and topology; demonstration of necessity changing thick film technology of metallization to vacuum sputtering by reducing of power consumption. The results show possibility to fast fabrication of different topologies for ceramic MEMS microhotplate in form-factor of SOT-23 type SMD package.

Improvements in the electromechanical properties of stretchable interconnects by locally tuning the stiffness

Recent advances in materials science and structural design have changed electronic applications from being bulky and rigid objects to small and soft products that have emerged for a wide range of applications, especially human-related products for which mechanical adoption is the key requirement. A typical stretchable application consists of small-sized, rigid IC-chips and passive components interconnected by conductive tracks on soft substrates. The early failure of such devices initiates from the rigid-soft interface due to the accumulation of stress. Therefore, special attention is needed to reduce the strain concentration at the interface. In this paper, stretchable interconnects were fabricated using a screen-printing method and surface mounted devices (SMDs) were bonded using an isotropic conductive adhesive. By partially removing material from the substrate in areas a little way from the rigid components, the stiffness is locally reduced, and this leads to an increase in the local stiffness around the SMDs and hence shields the soft-rigid interface against the stress. Materials can be removed by two different patterns. A finite element analysis and experimental data show 11%–19% improvements in single pull-up tests for the modified samples. This approach makes the electromechanical behaviour independent of encapsulation properties.

Exploration of alternative routes for recycling critical metals from waste PCB and tantalum capacitors

Abstract Printed Circuit Boards (PCB), secondary source of critical metals, are usually recycled to recover precious metals. Alternative routes, aiming to pre-concentrate critical metals, were tested at lab scale. An up-scaling process is proposed involving a thermomechanical separation of PCB and surface mounted devices (SMD). PCB without SMD are treated by solvolysis for desilication and debromination. Further calcination provides a presumably leachable metallic mix. Tantalum capacitors, a specific type of SMD, are treated by pyrolysis, to isolate metallic cores, which are further leached to obtain 92% pure tantalum oxide. LCA data show that tantalum recycling process is profitable for the environment.

Using Field-Effect Gas Sensors for Monitoring H2 in Transformer Oil

Hydrogen can be released during the thermal decomposition of organic materials, therefore, monitoring its level in the working industrial high-voltage transformer oil allows you to identify the development of degenerative processes in advance, because these processes can lead to an accident in the future. In experiments has shown that highly sensitive and small-sized field effect gas sensor based on the metal-insulator-semiconductor structure can be used for measuring of Hydrogen in oil with direct contact of its structure with transformer oil. Given the harsh environmental conditions of hydrogen measurement the field effect capacity type gas sensor were fabricated by using laser micromilling technique for fabrication compact ceramic surface mounting device package and microheater for sustentation working temperature of metal-insulator-semiconductor structure.

Fabrication and Electrical Characterization of Printed Microresistors of Silver Nanoparticles Using Microcantilever-Based Printing Technology

In this article, we report the fabrication of printed microresistors (PMRs) of silver nanoparticles (AgNPs) based on microcantilever-based printing technology (MCPT). The PMRs have been fabricated using three different printing techniques based on MCPT, namely spot overwrite printing (SOP), dip-ink printing with SOP (DIPSOP), and surface-patterning tool drag printing (SDP). The fabrication process has been carried out over substrates such as glass, silicon, and polyethylene terephthalate (PET). A postprinting analysis has been carried out based on the electrical characterization of the PMRs, which shows SOP as the most preferred, DIPSOP as the most reliable, and SDP as the fastest printing technique having the highest uniformity of thickness. The electrical characterization of the PMRs shows that their average resistance varies from few ohms to kiloohms based on the print thickness. The printed resistors are single-material electronic devices (SMEDs) as we have used only AgNP ink for the complete fabrication of the device to avoid any interfacial mismatch and irregularities at the nanoscale. Moreover, the fabricated PMRs are smaller in size, have lower fabrication cost, and consume less power as compared to the standard surface-mount device (SMD) chip resistors and hence offer an effective alternative to be used as microchip resistors on printed circuit boards (PCBs).

Laser Micromilling Technology as a Key for Rapid Ceramic MEMS Devices

The flexible laser micromilling technology for ceramic MEMS production of microhotplates in the surface mount device (SMD) package is described. Current results demonstrate that using described technology makes it possible to manufacture all parts of MEMS sensor in the SMD with form factor of SOT-23 package type.

Enabling paper-based flexible circuits with aluminium and copper conductors

Implementing electronics systems on paper is an important area of flexible circuit technologies. One of the approaches is to print conductive inks onto paper substrates, on which silicon-based surface mount device components are mounted. However, one of the problems is that the printed conductors have unneglectable resistivity. In this paper, we present paper-based flexible circuits, using copper and aluminium conductors that are laminated onto paper substrates using a high-speed roll-to-roll method. Edge roughness inspections and repeated two-point bending tests are carried out to evaluate the manufactured flexible circuits. Three surface mount techniques are used to assemble standard surface mount device components onto the flexible circuits, including an isotropic conductive adhesive, an anisotropic conductive adhesive, and a low-temperature solder paste. Several characterizations are performed to the surface mount techniques, including contact resistance measurements, component bonding strength tests, assembled circuit bending tests, and scanning electron microscopy. The results of the characterizations suggest that flexible circuits made from Cu with paper substrate achieve satisfactory results for mechanical reliability, all surface mount techniques, and have the potential to be used on automatic component assembly lines. In order to test whether such flexible circuits and surface mount techniques can be used in implementing electronics systems, passive NFC tags with relative humidity sensing functionality are made, which are interrogated by an NFC equipped mobile phone.

DBC-Packaged Inverter Power Module for Integrated Motor-Inverter Design Used in 48 V Mild Hybrid Starter-Generator (MHSG) System

This paper presents an improved package design of an inverter power module specialized for the 48 V starter- generator used in 48 V mild hybrid vehicles. The inverter module, called the mild hybrid starter and generator (MHSG), is integrated with its motor for size/volume reduction. However, the integrated motor-inverter presents supplementary challenges, such as limited cooling capabilities, in addition to the challenges resulting from the elevated voltage of 48 V of the mild hybrid systems. The proposed MHSG power module addresses these challenges. Parallel-connected metal-oxide-semiconductor field-effect transistor (MOSFET) dies were solder-bonded onto a direct bonded copper (DBC) substrate, and three DBC substrates (providing six legs) were assembled in a custom housing mounted on a forced air cooler. Shunt resistors and surface-mount device components were also soldered onto the DBC substrates. For improved stability and balance, ribbon bonding was used instead of wire bonding, the module components were repositioned, and DBC patterns were adjusted. The aforementioned approaches minimized the parasitic inductance, unbalanced/concentrated current density, and maximum temperature of the 48 V MHSG inverter module. The proposed module was validated through multiphysics finite-element method (FEM) simulations, manufactured prototypes, and experiments, all of which confirmed that the proposed module exhibits the electrical/thermal characteristics required for 48 V integrated MHSG systems.

A New Recognition and Pose Estimation of Tiny Electronic Parts Using Principal Component Analysis and Harris Corner Features

The center coordinates and rotated angle of the electronic part must be precisely estimated in case of palletizing the parts by picking and placing the parts to output tray by a robot, especially, the tiny parts like surface mounting device (SMD). A machine vision algorithm must be used in recognizing the type as well as estimating the pose of the parts. In this paper, we propose not only a recognition algorithm of electronic part using Principal Component Analysis [PCA] combined with Harris corner feature (HCF) and least mean square error (LMSE) for the matching of the part with data base, but also a precise pose estimation of the recognized part by using the extracted four corners from HCF combined with lines from Hough transformation (LHT). Applying the proposed algorithm to the test setup of five kinds of SMDs, we verified the usefulness of the proposed algorithm in accurate pose estimation as well as in recognition of type of the parts even in environment with illumination changes.

An Overview of the Development of Antenna-in-Package Technology for Highly Integrated Wireless Devices

Antenna-in-package (AiP) technology, in which there is an antenna (or antennas) with a transceiver die (or dies) in a standard surface-mounted device, represents an important antenna and packaging technology achievement in recent years. AiP technology has been widely adopted by chipmakers for 60-GHz radios and gesture radars. It has also found applications in 77-GHz automotive radars, 94-GHz phased arrays, 122-GHz imaging sensors, and 300-GHz wireless links. It is believed that AiP technology will also provide elegant antenna and packaging solutions to the fifth generation and beyond operating in the lower millimeter-wave (mmWave) bands. Thus, one can conclude that AiP technology has emerged as the mainstream antenna and packaging technology for various mmWave applications. This article will provide an overview of the development of AiP technology. It will consider antennas, packages, and interconnects for AiP technology. It will show that the antenna choice is usually based on those popular antennas that can be easily designed for the application, that the package choice is governed for automatic assembly, and that the materials and processes choices involve tradeoffs among constraints, such as electrical performance, thermal–mechanical reliability, compactness, manufacturability, and cost. This article also shows a probe-based setup to measure mmWave AiP impedance and radiation characteristics. It goes on to give AiP examples implemented, respectively, in a low-temperature co-fired ceramic, an embedded wafer level ball grid array process, and a high-density interconnect processes. Finally, this article will summarize and present some recommendations on research topics to further the state of the art of AiP technology.

두 개의 컨볼루션 신경망을 이용한 PCB 상의 SMD 분류 시스템

It is important to classify SMD(Surface Mount Device) type for programing of AOI. A new SMD classification system is proposed using series of two CNNs to improve accuracy. A series of device region detection CNN and classification CNN are proposed where the first network is device region detect network and second network is device classification network. The device region detect network is designed lighter than the previously used region detect network. Experimental results showed that better accuracy is obtained when classification is performed after region detection.

Integrated multilayer stretchable printed circuit boards paving the way for deformable active matrix

Conventional rigid electronic systems use a number of metallization layers to route all necessary connections to and from isolated surface mount devices using well-established printed circuit board technology. In contrast, present solutions to prepare stretchable electronic systems are typically confined to a single stretchable metallization layer. Crossovers and vertical interconnect accesses remain challenging; consequently, no reliable stretchable printed circuit board (SPCB) method has established. This article reports an industry compatible SPCB manufacturing method that enables multilayer crossovers and vertical interconnect accesses to interconnect isolated devices within an elastomeric matrix. As a demonstration, a stretchable (260%) active matrix with integrated electronic and optoelectronic surface mount devices is shown that can deform reversibly into various 3D shapes including hemispherical, conical or pyramid.

Design of Energy Monitoring System for Small Scale Wind Turbine Applications

In this paper, an energy monitoring system for small scale wind turbine is proposed. The monitoring system process includes measuring wind turbine power output (voltage and current) and storing systems. The measurement results will be stored in a micro SD at the real time. All processes for measuring and storing data in a data logger were carried out by a microcontroller through several sensors and storage media. The data logger were designed and implemented as small as possible to save material and enhance the performance of serial communication between components inside. Hence, most of components are installed by Surface Mounting Device (SMD) packaging resulted a compact data logger size as 7cm x 8cm. Furthermore, by using FAT32 system files, the data logger is able to operate a micro SD with a size of up to 32GB. Finally, this data logger shows a good capability for measuring voltage, current and storing the results into the SD card including the measurement period.

Determining Phosphor Temperature in Light-Emitting Diode Based on Divisional Normalized Emission Power

We propose a non-contact method for determining phosphor/silicone temperature (phosphor temperature) in phosphor-coated light-emitting diode (pc-LED). The pc-LED with a surface mounted device (SMD) structure is primarily consisted of InGaN/GaN blue LED chip, (Sr,Ca)AlSiN3:Eu2+ red rare-earth phosphor, and transparent dimethyl silicone. This proposed method is basically based on a linear temperature dependence of divisional normalized emission power for phosphor/silicone mixture. Four types of pc-LED corresponding to four different phosphor concentrations are examined by proposed method. A comparison of measured results between micro-thermocouple device and proposed method has also been carried out, showing a fairly good agreement between them, except for pc-LED with 4.8 wt% phosphor concentration. We suggest that this proposed method can provide a useful tool for further study of optical and thermal characteristics in pc-LED.

Ferrites in Transfer Molded Power SiPs – Challenges in Packaging

Abstract Transfer-Molding-Process is enjoying growing interest when aiming for novel high-power density System-in-Packages (Power SiPs), where not only transistors and diodes, but also drivers, passives, coils and transformers are supposed to be integrated in one package. Encapsulating modules in a Transfer-Molding-Process induces higher mechanical load onto module components compared to conventional silicone potting. Previous investigations have shown, that integration of delicate components as ferrite cores into molded packages is not as trivial as integration of conventional Surface Mount Devices (SMDs) or power semiconductors; the brittle ferrites tend to fracture during the encapsulation process, resulting in higher ferrite core loss. The present study aims to identify main root causes for ferrite core cracking during manufacturing of molded Power SiPs. The test vehicle is a symmetrical Printed Circuit Board (PCB) based package with three pairs of E-shaped ferrite cores. The Epoxy Molding Compound (EMC) deployed here is characterized to enable filling simulations. Since technical datasheets of ferrites typically lack specifications of mechanical properties, ferrite materials are analyzed in more detail. Filling simulations and thermo-mechanical simulations are performed in order to gain insight into process-induced stress, which may induce cracks in the ferrites. In addition, different ferrite designs are evaluated regarding core losses and mechanical stability, and thus their tendency to fracture.

Multi-Objective Optimization of Decoupling Capacitors for Placement and Component Value

A multiobjective evolutionary method is proposed for the optimization of surface mount device (SMD) multilayer ceramic chip (MLCC) capacitors used for decoupling on printed circuit boards (PCBs) with resonant power–ground plane pairs. The proposed approach provides options for designers to meet power integrity specifications by employing uniform-valued capacitors that help to reduce the bill-of-material (BOM) cost and mitigate the part procurement risk. It is also shown that uniform MLCC capacitors with variable distance from power pins can have a similar decoupling effect to an assortment of capacitors. By simultaneously optimizing the pin-capacitor distance and value, the proposed method is shown to allow for the allocation of fewer decoupling capacitors under the ball-grid-array (BGA) pin field of an integrated circuit (IC) device.