Selection Of Substrate Material Research Articles

Designing a High Gain Rectangular Microstrip Patch Antenna Working at 3 GHz for RADAR

This study presents the design and analysis of a microstrip patch antenna optimized for radar applications operating at a frequency of 3 GHz. The antenna is designed to meet the requirements of radar systems, offering characteristics such as high gain, low profile, and broad bandwidth. The design process involves simulation using electromagnetic simulation software to achieve the desired antenna performance parameters. Various antenna parameters, including substrate material selection, patch dimensions, feeding techniques, and impedance matching networks, are carefully optimized to enhance antenna performance. The proposed antenna design is expected to exhibit excellent radiation characteristics, making it suitable for radar applications requiring reliable and efficient communication at 3 GHz frequency. This antenna designed for operating at 3 GHz, type Rogers Ultralam1217 (tm) with dielectric constant, ∈r= 2.2 tanδ (0.0009) and thickness of h = 1.6mm. The antennas are simulated using Ansys HFSS software. The performance is evaluated in terms of return loss, gain, and directivity and is deemed to be compatible with simulations.

The Effect of Isothermal Aging on the Intermetallic Growth between SN100C Lead-Free Solders and ENIG Surface Finish

The selection of substrate material depends on solder joint requirements and will influence intermetallic compound (IMC) layer formation and reliability of the solder joints. Besides, using different solder materials can also affect the microstructure of IMCs formed during soldering and isothermal ageing process. This study investigated the effect of the IMC formation and microstructure evolution during reflow soldering and isothermal ageing using SN100C lead-free solders and ENIG surface finish. The characterization of the IMC formed during both reflow soldering and isothermal ageing in terms of the type, morphology, and thickness is then analyzed by using the Optical Microscope (OM), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). The result reveals that there are two IMC formed at an interface between SN100C and ENIG which are (Cu, Ni)6Sn5 and (Ni, Cu)3Sn4 where (Ni, Cu)3Sn4 grows beneath (Cu, Ni)6Sn5. The thickness of the IMC formation in the SN100C/ENIG solder joint is also directly proportional to the ageing duration, indicating that the longer the time of the IMC exposed to high temperature affects the thickness of the IMC.

Sluggish Electron Transfer of Oxygen-Terminated Moderately Boron-Doped Diamond Electrode Induced by Large Interfacial Capacitance between a Diamond and Silicon Interface.

Boron-doped diamond (BDD) has tremendous potential for use as an electrode material with outstanding characteristics. The substrate material of BDD can affect the electrochemical properties of BDD electrodes due to the different junction structures of BDD and the substrate materials. However, the BDD/substrate interfacial properties have not been clarified. In this study, the electrochemical behavior of BDD electrodes with different boron-doping levels (0.1% and 1.0% B/C ratios) synthesized on Si, W, Nb, and Mo substrates was investigated. Potential band diagrams of the BDD/substrate interface were proposed to explain different junction structures and electrochemical behaviors. Oxygen-terminated BDD with moderate boron-doping levels exhibited sluggish electron transfer induced by the large capacitance generated at the BDD/Si interface. These findings provide a fundamental understanding of diamond electrochemistry and insight into the selection of suitable substrate materials for practical applications of BDD electrodes.

Development of Specialized Microelectrode Arrays with Local Electroporation Functionality

When a cell or tissue is exposed to a pulsed electric field (100–1000 V/cm), the cellular membrane permeabilizes for biomolecules that cannot pass an intact cellular membrane. During this electropermeabilization (EP), plasmid deoxyribonucleic acid sequences encoding therapeutic or regulatory genes can enter the cell, which is called gene electrotransfer (GET). GET using micro-/nano technology provides higher spatial resolution and operates with lower voltage amplitudes compared to conventional bulk EP. Microelectrode arrays (MEAs), which are usually used for the recording and stimulation of neuronal signals, can be utilized for GET as well. In this study, we developed a specialized MEA for local EP of adherent cells. Our manufacturing process provides a most flexible electrode and substrate material selection. We used electrochemical impedance spectroscopy to characterize the impedance of the MEAs and the impact of an adherent cellular layer. We verified the local EP functionality of the MEAs by loading a fluorophore dye into human embryonic kidney 293T cells. Finally, we demonstrated a GET with a subsequent green fluorescent protein expression by the cells. Our experiments prove that a high spatial resolution of GET can be obtained using MEAs.

Development of high performance flip chip ball grid array (FCBGA) packages for automotive application processors

Automobiles have witnessed rapid proliferation of infotainment, driver assistance and autonomous driving features which have led to significant increase in semiconductor content per car. However, this has also required increased integration of device functionality to meet the new automotive requirements for in-vehicle networking, autonomous driving, infotainment, and sensor integration. Advance technology/packages are needed to provide ideal solutions for automotive grade reliability, high electrical performance, and multi-function integration for automotive application processors. To address these requirements, innovative packages including Flip Chip Ball Grid Array (FCBGA) are the potential solutions. In this study FCBGA packages are developed for automotive processor application and qualified for AEC2 qualification tier. To achieve higher performance and reliability, different package substrate materials such as core dielectric and build-up dielectric were evaluated. Mechanical modelling and simulation of package reliability and influence of key material properties such as coefficient of thermal expansion (CTE), modulus of elasticity (E) and glass transition temperature (Tg) was used to provide guidance for the selection of substrate and assembly materials. Developed packages met all the product performance requirements and passed package qual conditions of high temperature storage life (150°C, 500 hours), temperature cycling (-55 °C to 125 °C, 1000 cycles), temperature humidity bias (85 °C, 85% RH, 1000 hours) and board level temperature cycling (-40 °C to 125 °C, 1000 cycles).

Phonon transport mechanism of HfO2 ultrathin film with temperature-correction full-band Monte Carlo simulation

Hafnium dioxide (HfO2) has been widely used in microelectronics nowadays and commonly withstands extremely high temperatures, so the investigation of its thermodynamic properties is particularly essential. This paper develops a temperature-correction full-band Monte Carlo (TFMC) method to investigate the HfO2 ultrathin film. The phonon dynamics parameters of HfO2 are calculated based on the first-principles method. TFMC can better describe the phonon cumulative distribution function in different temperatures by modifying the phonon relaxation time and heat capacity. The thermal conductivity of HfO2 ultrathin film is calculated based on the above method and is in good agreement with the literature. It is observed that the optical phonons in HfO2 ultrathin film are prominent in the phonon heat transport, which is quite different from the mechanism in common semiconductor materials. Combined with the full-band diffuse mismatch model, the Si-based HfO2 ultrathin film is studied. It is found that the existence of the interface with substrates improves the thermodynamic properties of the ultrathin film, which provides a reference for the selection of substrate materials.

Direct Patterning of ZnO Deposition By Atomic-Layer Additive Manufacturing Using a Safe and Economical Precursor

AS-ALD has the potential to overcome many of the challenges the semiconductor industry is facing by enabling self-aligned fabrication, instead of lithography’s cost, resit, equipment. Main challenges in AS-ALD are the need for pre-patterned substrates, defects outside of the desired growing area resulting from insufficient selectivity, and limited selection of substrate materials that allow deposition. [1, 2]To overcome these challenges, we chose for the first time the novelty of direct patterning with an AL-3D printer, also called atomic layer additive manufacturing (ALAM). 3D-printing is a flexible and efficient tool for reducing the cost and time spend for designing and manufacturing. AL-3D in principle functions similar to conventional g-ALD and the special design of nozzle led in producing direct patterning. All the commercially available precursors which have been used in g-ALD are compatible with our invented equipment and not only we can produce the same films conveniently but also this device allows us to use new precursors e.g. Zn(DMP)2 opening a new chemistry window. We have already deposited different materials TiO2, Pt, SiO2, Al2O3 successfully using TTIP, (MeCp)PtMe3, APTES, TMA as precursor. The ZnO process is very well behaved in ALD community as a diethylzinc (ZnEt2) precursor’s very high vapor pressure and its very high reactivity to water. Our attempts at reducing the amount of vapor delivered were successful in part but the results were not sufficiently reproducible, therefore we turned to the use of a new zinc precursor instead.In this work we focus on the new precursor Zn(DMP)2 instead of ZnEt2 for ZnO deposition. The Zn(DMP)2 has a very low vapor pressure, the ethyl groups are complemented by dimethylamino substituents that stabilize central zinc ion and thereby render the molecule less reactive to water. Our characterization results shows the deposited ZnO films with our new precursor has same structure and composition as with ZnEt2 with a constant growth rate of 1.0 Å per cycle. the crystals are oriented in a roughly isotropic manner.After testing Zn(DMP)2 in classical ALD we achieved to print homogeneous patterns with well-defined edges and uniform thicknesses among the whole pattern. The rough particulate deposits indicative of uncontrolled CVD-mode deposition obtained with the ZnEt2 + water reaction are completely absent of lines obtained from the Zn(DMP)2 + water reaction. Furthermore, we fabricate a metal oxide transistor MOSFET to demonstrate the practical applications of the device. Clark; K. Tapily; K.-H. Yu; T. Hakamata; S. Consiglio; D. O´Meara; C. Wajda; J. Smith; G. Leusink; Perspective: New Process Technologies Required for Future Device and Scaling. APL Mater. 2018, 6, 05203Fang; J. C. Ho, Area-Selective Atomic Layer Deposition: Conformal Coating, Subnanometer Thickness Control, and Smart Positioning. ACS Nano 2015, 9 (9), 8651-8654.

From impact to solidification in drop-on-demand metal additive manufacturing using MetalJet

Drop-on-demand metal jetting is a promising additive manufacturing (AM) technology that is gaining interest due to its capability to directly print complex single and multi-material components at high resolutions. It also has key advantages over other metal AM techniques, such as avoiding powder handling and extensive post-processing. In this method, parts are built via spatially controlled deposition of individual molten droplets onto a substrate. Therefore, the success of the process entirely depends on the behaviour of these single droplets from deposition to solidification including their interactions with the substrate, which is scarcely investigated to date. To fill this research gap, the in-house MetalJet platform was used to investigate the spreading and solidification of metallic micro-droplets at low Weber numbers. This was undertaken onto various substrates using a range of jetting and substrate temperatures through an integrated experimental, analytical, and computational approach. This study reports that increasing the substrate temperature enhanced the diffusion between the droplet and substrate, hence improving the bonding. Moreover, ripples forming on a droplet’s periphery during solidification disappeared at elevated substrate temperatures, resulting in improved inter-droplet bonding. Furthermore, the significant role of the substrate wettability and thermal properties, which control the droplet’s dynamics and solidification behaviour, respectively, is elucidated. This highlights the importance of substrate material selection using this technology. The results presented in this article underpin the optimal process conditions under which the 3D structures produced with this technology can exhibit reliable integrity and consistency. This represents a step forward in the direct metal printing of high resolution functional multi-material components.

Optimization of ultra-wide band antenna by selection of substrate material using artificial neural network

Optimization of ultra-wide band antenna by selection of substrate material using artificial neural network

Substrate material selection model for dual-band multilayer diffractive optical elements with wide angle of incidence

Large angle of incidence and multi-band are the goals pursued by modern multilayer diffractive optical element (MLDOE). The polychromatic integral diffraction efficiency (PIDE) is sensitive to the incident angle and refractive index of the substrate material. Therefore, we propose a new solution for selecting a set of optimal substrate materials of MLDOE to obtain the maximum PIDE in a large angle incidence. A mathematical model is established and the substrate material selection method based on comprehensive PIDE difference comparison (SMS-CPDC) for dual-band MLDOE is proposed. The three-layer DOEs in visible-NIR dual-band and the double-layer DOEs in MWIR-LWIR dual-band are designed and discussed as the examples. In visible-NIR dual-band and MWIR-LWIR dual-band, the optimal substrate material combinations are N-PK52A-PC-P-SF69 and ZNSE-ZNS, respectively. When the comprehensive PIDE decreases to 90%, the available incident angle range is ± 51.6° for N-PK52A-PC-P-SF69 MLDOE and that is ± 10.9° for ZNSE-ZNS MLDOE; When the comprehensive PIDE decreases to 85%, the available incident angle range is ± 54.2° for N-PK52A-PC-P-SF69 MLDOE and that is ± 12.1° for ZNSE-ZNS MLDOE. The results are of great significance for the application of MLDOEs in hybrid system with a large range of incident angle and multi operating band.

Effect of substrate roughness and material selection on the microstructure of sputtering deposited boron carbide thin films

Amorphous boron carbide (B4C) thin films are by far the most popular form for the neutron converting layers in the 10B-based neutron detectors, which are a rising trend in detector technologies in response to the increasing scarcity and price of 3He, the standard material for neutron detection. The microstructure of the B4C films is closely related to the important properties, e.g. density and adhesion, for the converting layers, which eventually affect the detection efficiency and the long-term stability of the detectors. To study the influence from substrates of different roughness and materials, the B4C films were deposited on polished Si substrates with Al, Ti, and Cu buffer layers and unpolished Si, Al, Ti, and Cu substrates by direct current magnetron sputtering at a substrate temperature of 623 K. The tapered columnar grains and nodular defects, generally observed in SEM images, indicated a strong shadowing effect where voids were introduced around the grains. The change in the grain size did not show a direct dependence to the substrate roughness, acquired from the surface profile, nor to the mass density of the films, obtained from reflectivity patterns. However, films with non-uniform size of columnar grains were deposited on substrates with high skewness, leading to a drop of mass density from ~95% down to ~70% of tabulated bulk density. On the other hand, similar microstructures and mass density were obtained from the films deposited on Al, Ti, and Cu of different roughness and good adhesion were observed from cross-cut adhesion tests, showing the reliability of sputtering deposited B4C films on common structural materials in neutron detectors.

A compact high gain wideband millimeter wave 1 × 2 array antenna for 26/28 GHz 5G applications

PurposeThis paper aims to present the design, fabrication and analysis of a wideband, enhanced gain 1 × 2 patch antenna array with a simple profile structure to meet the desired antenna traits, such as wide bandwidth, high gain and directional patterns expected for the upcoming fifth-generation (5G) wireless applications in the millimeter wave band. To enhance these parameters (bandwidth and gain), a new antenna geometry by using a T-junction power divider is presented.Design/methodology/approachThe theory behind this paper is connected with advancements in the 5G communications related to antennas. The methodology used in this work is to design a high gain array antenna and to identify the best possible power divider to deliver the power in an optimized way. The design methodology adopts several steps like the selection of proper substrate material as per the design specification, size of the antenna as per the frequency of operation and application-specific environment condition. The simulation has been performed on the designed antenna in the electromagnetic simulation tool (high-frequency structure simulator [HFSS]), and optimization has been done with parametric analysis, and then the final array antenna model is proposed. The proposed array contains 2-patch elements excited by one port adapted to 50 Ω through a T-junction power divider. The 1 × 2 array configuration with the suggested geometry helps to improve the overall gain of the antenna, and the implementation of the T-junction power divider provides enhanced bandwidth. The proposed array designed using a 1.6 mm thick flame retardant substrate occupies a compact area of 14 × 12.14 mm2.FindingsThe prototype of the array antenna is fabricated and measured to validate the design concept. A good agreement has been reached between the measured and simulated antenna parameters. The measured results confirm its wideband and high gain characteristics, covering 24.77–28.80 GHz for S11= –10 dB with a peak gain of about 15.16 dB at 27.65 GHz.Originality/valueThe proposed antenna covers the bandwidth requirements of the 26 GHz n258 band (24.25–27.50 GHz) to be deployed in the UK and Europe. The suggested antenna structure also covers the federal communications commission (FCC)-regulated 28 GHz n261 band (27.5–28.35 GHz) to be deployed in America and Canada. The low profile, compact size, simple structure, wide bandwidth, high gain and desired directional radiation patterns confirm the applicability of the suggested array antenna for the upcoming 5 G wireless systems.

Surface Topography of PVD Hard Coatings

The primary objective of this study was to investigate and compare the surface topography of hard coatings deposited by three different physical vapor deposition methods (PVD): low-voltage electron beam evaporation, unbalanced magnetron sputtering and cathodic arc evaporation. In these deposition systems, various ion etching techniques were applied for substrate cleaning. The paper summarizes our experience and the expertise gained during many years of development of PVD hard coatings for the protection of tools and machine components. Surface topography was investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), scanning transmission electron microscopy (STEM) and 3D stylus profilometry. Observed similarities and differences among samples deposited by various deposition methods are discussed and correlated with substrate material selection, substrate pretreatment and deposition conditions. Large variations in the surface topography were observed between selected deposition techniques, both after ion etching and deposition processes. The main features and implications of surface cleaning by ion etching are discussed and the physical phenomena involved in this process are reviewed. During a given deposition run as well as from one run to another, a large spatial variation of etching rates was observed due to the difference in substrate geometry and batching configurations. Variations related to the specific substrate rotation (i.e., temporal variations in the etching and deposition) were also observed. The etching efficiency can be explained by the influence of different process parameters, such as substrate-to-source orientation and distance, shadowing and electric field effects. The surface roughness of PVD coatings mainly originates from growth defects (droplets, nodular defects, pinholes, craters, etc.). We briefly describe the causes of their formation.

Advances in strain engineering on oxide heteroepitaxy

Advances in strain engineering on oxide heteroepitaxy

Substrate material selection and design optimization of patch antenna

In this paper parametric analysis of different substrate materials used for microstrip patch antenna are analyzed based on its physical properties, also parametric calculation performed for selection of substrate working at operating frequency of 5.8 GHz. Proposed microstrip patch antenna was optimized by varying its design structure from rectangular patch to E-shaped structure. Method of moment based electromagnetic simulator IE3D was used for parametric calculation and optimization of proposed patch antenna design.

Culture Substrates for Improved Manufacture of Mesenchymal Stromal Cell Therapies.

Recent developments in mesenchymal stromal cell (MSC) therapies have increased the demand for tools to improve their manufacture, including the selection of optimal culture substrate materials. While many clinical manufacturers use planar tissue culture plastic (TCP) surfaces for MSC production, others have begun exploring the use of alternative culture substrates that present a variety of spatial, mechanical, and biochemical cues that influence cell expansion and resulting cell quality. In this review, the effects of culture and material properties distinct from traditional planar TCP surfaces on MSC proliferation, surface marker expression, and commonly used indications for therapeutic potency are examined. The different properties summarized include the use of alternative culture formats such as cellular aggregates or 3D scaffolds, as well as the effects of culture substrate stiffness and presentation of specific adhesive ligands and topographical cues. Specific substrate properties can be related to greater cell expansion and improvement in specific therapeutic functionalities, demonstrating the utility of culture materials in further improving the clinical-scale manufacture of highly secretory MSC products.

Performance Comparison of Microchannel Heat Sink Using Boron-Based Ceramic Materials

Microchannel heat sink plays a vital role in removing a considerable amount of heat flux from a small surface area from different electronic devices. In recent times, the rapid development of electronic devices requires the improvement of these heat sinks to a greater extent. In this aspect, the selection of appropriate substrate materials of the heat sinks is of vital importance. In this paper, three boron-based ultra-high temperature ceramic materials (ZrB2, TiB2, and HfB2) are compared as a substrate material for the microchannel heat sink using a numerical approach. The fluid flow and heat transfer are analyzed using the finite volume method. The results showed that the maximum temperature of the heat source didn’t exceed 355K at 3.6MWm-2 for any material. The results also indicated HfB2 and TiB2 to be more useful as a substrate material than ZrB2. By applying 3.6 MWm-2 heat flux at the source, the maximum obtained surface heat transfer coefficient was 175.2 KWm-2K-1 in a heat sink having substrate material HfB2.

Investigation on the Growth and Properties of Six Garnet Single Crystals with Large Lattice Constants

AbstractLarge lattice constant Y3Al5O12, Gd3Ga5O12 (GGG), Y3Sc2Ga3O12 (YSGG), Gd3Sc2Ga3O12, Ca0.4Mg0.25Zr0.65Gd2.6Ga4.1O12 (CaMgZr:GGG), and Gd1.17Y1.83Sc2Ga3O12 (GYSGG) substrate crystals with 2 in. in diameter are grown by the Czochralski (Cz) method, their physical, chemical, and optical properties are analyzed and compared in details. The X‐ray rocking curves (XRCs) illustrate that the as‐grown crystals possess high crystalline quality. The lattice constants of six crystals are calculated and that of GYSGG can be easily adjusted in the range of 1.2450–1.2565 nm by changing the Gd/Y proportion. The dislocation densities on the (111)‐crystalline face are about 102 cm−2 order of magnitude. The thermal conductivities of six crystals are measured to be 11.72, 8.98, 6.83, 5.45, 4.67, and 4.66 W m−1 K−1, respectively. It is found that the thermal expansion coefficients of six crystals can be reduced by annealing at 1273 K for 60 h. In addition, the transmission spectra show that the six crystals have excellent transparency and the coefficients of the Sellmeier equation are fitted by the calculated refractive indices. These results of the six crystals can provide the necessary parameters and references for the selection of suitable substrate materials or laser host crystals.

MIMO antenna miniaturization standards for future 5G

PurposeThe fifth-generation technology 5G, the planned successor to 4G, is a new global standard for mobile networks that brings virtual to reality. 5G wireless technology enables the delivery of high speed, low latency, reliability, 100% coverage and availability to connect number of users as in massive IoT applications.Design/methodology/approachWith expeditious development in wireless communication, the need for enhanced characteristic antenna design such as the size of the antenna, high data rate, demand in traffic, bandwidth, gain and efficiency increases. Various antenna designs are to be explored to meet the needs and achieve trade-offs between antenna size vs cost, high gain and efficiency vs less loss, high B.W and data rate with the selection of appropriate substrate materials and various gain & isolation enhancement techniques.FindingsThis paper thus gives scope for miniaturized MIMO antenna design for mobile applications at mm-wave frequency range.Originality/valueThis paper thus gives scope for miniaturized MIMO antenna design for mobile applications at mm-wave frequency range.

Fundamental understanding of electrochemical catalytic performance of carbonized natural wood: wood species and carbonization temperature

The pore structure and carbonization temperature of wood have a great influence on the electrocatalytic performance of wood carbon. This work is of great significance for the selection of suitable wood carbon substrate materials for electrocatalysis.