Wiring Density Research Articles

Designed wrinkles for optical encryption and flexible integrated circuit carrier board

Patterns on polymers usually have different mechanical properties as those of the substrates, causing deformation or distortion and even detachment of the patterns from the polymer substrates. Herein, we present a wrinkling strategy, which utilizes photolithography to define the area of stress distribution by light-induced physical crosslinking of polymers and controls diffusion of residual solvent to redistribute the stress and then offers the same material for patterns as substrate by thermal polymerization, providing uniform wrinkles without worrying about force relaxation. The strategy allows the recording and hiding of up to eight switchable images in one place that can be read by the naked eye without crosstalk, applying the wrinkled polymer for optical anti-counterfeiting. The wrinkled polyimide film was also utilized to act as a substrate for the creation of fine copper circuit by a full-additive process. It generates flexible integrated circuit (IC) carrier board with copper wire density of 400% higher than that of the state-of-the-art in industry while fulfilling the standards for industrialization.

Amorphous B coated Mg nanopowder induces low angle grain boundaries and enhances J c of MgB2 wire

In this work, amorphous B coated Mg nanopowder (BCMN) is synthesized and transport property of MgB2 superconducting wire is significantly enhanced with different contents of BCMN. BCMN has high reactivity since it contains nanoscale Mg and amorphous B. It allows to obtain MgB2 nanocrystals at only 400 °C with the compression of a lattice parameter and expansion of c lattice parameter compared to MgB2 formed by micron-sized Mg mixed with amorphous B (Mg + B) powders. These MgB2 nanocrystals serve as crystal nuclei and promote the crystallization and growth of MgB2. The mismatch of different lattice parameters prepared using BCMN and M + B powders induces low angle grain boundaries (LAGBs) embedded in MgB2 grains. LAGBs act as plane defects, leading to a dominant surface pinning mechanism and an enhancement in the critical current density on the magnetic field (J c(H)). At 4.2 K in 6 T, transport critical current density (J ct) of wire with 20 wt.% BCMN is 6.7 × 104 A·cm−2, approximately 1.8 times wire with 0 wt.% BCMN.

Improvement of plastic deformation property and current carrying capacity of Bi2212 wires through low oxygen partial pressure post-annealing of precursor

The performance of superconducting magnets is greatly dependent on the size and uniformity of the superconducting filaments within the wire. However, in the fabrication of Bi2Sr2CaCu2Ox (Bi2212) wires using ceramic oxide as the superconducting filaments, we face multiple challenges including filament fragility, poor uniformity, and non-smooth Ag/superconductor interfaces. These challenges primarily stem from the significantly lower plastic deformation capability of ceramic oxide powder filaments compared to metal matrices. To address these challenges, this study focuses on the modification of ceramic oxide precursor powders. Through the utilization of low-temperature, low oxygen partial pressure (pO2) heat treatment, we have observed significant changes in the Cu chemical states and lattice parameters within the Bi2212 grains. These alterations have proven to be highly effective in reducing the energy required for grain sliding and, in turn, enhancing the plastic deformation properties of the Bi2212 oxide filament. Furthermore, post-annealing the oxide powder under low pO2 conditions narrows the gap in plastic deformability between the Ag sheath and the oxide filaments, resulting in improved filament uniformity and a smoother Ag/oxide interface in Bi2212 wires. Notably, the Bi2212 grains exhibit an orderly arrangement within the wires. As a result of these improvements, the critical current density (Jc) of the final wires increases by an impressive 70 %. The outcomes of this study are not only crucial for producing Bi2212 magnets with higher magnetic field strength, improved magnetic field uniformity, and enhanced operational stability, but also offer fresh insights and methodologies for advancing the field of superconducting materials.

Theoretical study of susceptibility and effective mass in semiconductor quantum well-wires

The susceptibility and effective mass of electrons and hole vary as functions of carrier density and temperature in parabolic lateral barrier quantum-well wires (QWWRs). To investigate these properties, we utilize the leading-order dynamically screened Coulomb interaction, wherein the electron self-energy is calculated within the plasmon-pole approximation (PPA). All findings for GaAs QWWRs reveal a substantial difference between susceptibility and effective mass at low and high temperatures for varying carrier densities. These results contribute to illuminate of how Coulomb interactions and exchange–correlation energies influence the susceptibility and effective mass of GaAs semiconductors across a broad range of temperature and carrier density conditions.

Digital twin driven intelligent manufacturing for FPCB etching production line

Flexible printed circuit board (FPCB) exhibits high wiring density and good bendability to be widely used in smart devices. Traditional FPCB etching production lines are mostly discrete manufacturing workshops, which need to be upgraded with intelligence to meet the production requirements of high precision, production efficiency, and product yield. As an emerging technology, the digital twin can achieve the interoperability between physical and digital worlds of manufacturing systems. In this study, a digital twin driven FPCB etching intelligent production line is design. Data service system obtains comprehensive data from the production line in real time and provides intelligent data services. Real time mapping and online control system accomplishes the real time mapping and closed-loop control of intelligent production line. Key process databases are established to obtain optimal process parameters by analyzing the key processes of FPCB etching intelligent production line. The result shows that the process parameters of production line can be updated and adjusted accurately in real time to ensure good consistency and reliability of products. Currently, the FPCB etching intelligent production line can achieve the line forming at the minimum 16 μm line pitch and significantly improve the product yield.

Theoretical study of electron compressibility in semiconductor quantum wires

The compressibility was calculated of electrons as a function of external magnetic, temperature and carrier density in the parabolic lateral barrier quantum wires (QWRs). The compressibility found by using Seitz's theorem in which electron self-energy is calculated within the random-phase approximation. All results for GaAs QWRs show that a large difference between the compressibility in low- and high-temperature region at external magnetic fields. These results can help clarify how the Coulomb interaction and exchange, correlation energy affect the compressibility of the semiconductor across a wide range of density, temperature, and external magnetic.

Dynamic low power management technique for decision directed inter-layer communication in three dimensional wireless network on chip

3D ICs, a novel technology, might significantly impact multicore NoCs with hundreds or thousands of processing components on a single chip. Multiple 2D chips can be stacked vertically to create multiple active processing elements at various levels. Adding active device layers to 3D ICs can enhance system performance, increase functionality, and increase packing density. New architectural and IC technology advancements hinder energy-efficient design research. Achieving a balance between chip power and performance is crucial. This paper describes the “Dynamic Low Power Management Method in 3DWiNoC” (DLPM 3DWiNoC) architecture, which enables self-organized, centrally managed service management using Smart Master Agents. The approach utilizes SMA's ODA DD module for self-organized, centrally managed service management. To improve power regulation, data flow across vertical interconnects (TSVs) is reconfigured based on a dynamic evaluation of channel link use. SMA aims to reduce congestion by increasing connection utilization through high-frequency, bi-directional vertical channels via TSVs. The suggested system is modeled in MATLAB Simulink. Compared to 3D stacking, TSV stacking of vertical interconnects with the SMA method ensures low parasitic (latency and power) and higher bandwidth with higher vertical wire densities. Experimental results show that the proposed architecture decreases area overhead by 5%-7%, network latency by 12%-15%, and NoC power consumption by 15%-20% compared to the present multi-NoC design.

Interfacial reactions and critical current density of Cu-sheathed Cu-doped MgB2 wire with Ti diffusion barrier

Development of reaction zones at the core Mg(Cu) – boron (B) and barrier (Ti) – sheath (Cu) interfaces of an internal magnesium diffusion (IMD) manufactured MgB2 composite wire has been studied at varying temperatures of 560–665 °C for 30 min and varying time periods of 30–180 min at 560 °C. MgB2 has predominantly formed at the Mg(Cu) – B interface with little solubility of Cu of 1–3 at%. A second phase enriched with Cu, Mg2Cu, has also formed at random locations within the MgB2 phase matrix, indicating the advantage of doping Cu in the Mg rod. However, a layer of another B-rich phase, MgB4, has also formed at a higher temperature of 665 °C with negligible solubility of Cu at the MgB2 – B interface. At the Ti – Cu interface, the formation of CuTi2, CuTi, Cu4Ti and Cu4Ti3 intermetallic phases took place. However, the Cu4Ti and Cu4Ti3 phases develop after annealing the wire at a relatively higher temperature of 620 °C and at 560 °C with progress in annealing time. Critical current density (Jc) decreases with annealing time; however, the sensitivity of Jc towards annealing time is low. Critical current density is found to be strongly dependent on the annealing temperature of the composite wires for the formation of the MgB2 superconductor phase. A maximum critical current density of ∼ 2.5 × 104 A/cm2 at 5 T and 4.2 K is attained for the Cu-doped MgB2 composite wire when annealed at 665 °C for 30 min. A maximum shift of only 0.5 K is measured for MgB2 when formed at the highest annealed temperature compared to the lowest one in this study.

Prediction of Fill Factor and Charge Density of Self-Shielding Flux-Cored Wire with Variable Composition

Prediction of Fill Factor and Charge Density of Self-Shielding Flux-Cored Wire with Variable Composition

Predicting the consequences of subsistence poaching on the population persistence of a non-target species of conservation concern

Illegal animal hunting, a contributor to biodiversity loss, occurs along a relative selectivity spectrum from indiscriminate to highly selective. Extensive research has evaluated the impacts of selective hunting on animal populations. In contrast, the ways in which indiscriminate hunting pressure can shape populations of non-target species has not yet received comparable attention. We used empirical field data collection and simulation modelling to predict the persistence of an African lion population (Panthera leo) subject to indiscriminate hunting pressure from non-target subsistence poaching via wire snares in Murchison Falls National Park, Uganda. Our simulation modelling predicted lion population extirpation following a 50 % rise of lethal poaching pressure above the observed levels. When lethal poaching pressure doubled, the lion population was extirpated in ~70 % of our simulations. We then simulated reductions in lethal poaching pressure to quantify the predicted population recovery of lions. We found that the lion population increased by 40 % with reductions in lethal poaching pressure of 50 %. When we removed lethal poaching pressure entirely, the lion population nearly doubled in just 18 years. Our results demonstrate that by reducing the density of wire snares in the study area by just 2.79/km2, the lion population transitioned from being locally extirpated in 67 % of the simulations to reaching carrying capacity inside of two lion generations. We explore how vulnerable even non-target animals are to subsistence poaching and describe the types of applied practices that can be implemented to reduce wire snaring and effectively promote the population recovery of species of conservation concern.

Polymer-Gated Transistors with Only One Solution-Processed, Single Crystalline Organic Microwire for Light and Oxygen Detection.

Organic semiconductors employed in single crystalline form have several advantages over polycrystalline films, such as higher charge carrier mobility and better environmental stability. Herein, we report the fabrication and characterization of a solution-processed microsized single-crystalline organic wire of n-type N,N'-dipentyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C5). The crystal was applied as an active layer in polymer-gated organic field-effect transistors (OFETs) and organic complementary inverter circuits. The single crystaiiline nature of PTCDI-C5 wires were characterized using two-dimensional grazing incidence wide-angle X-ray diffraction (2D-GIXD) and polarized optical microscopy. OFETs with the PTCDI-C5 crystals exhibited high n-type performance and air stability under ambient conditions. To investigate the electrical properties of the single-crystalline PTCDI-C5 wire more precisely, OFETs with only one PTCDI-C5 microwire in the channel were fabricated, and clear n-type characteristics with satisfactory saturation behavior were observed. The device with only one crystal wire exhibited characteristics with significantly lower variation compared to the multicrystal devices, which shows that the density of crystal wires is a critical factor in precisely investigating device performance. The devices exhibited a reversible threshold voltage shift under vacuum and oxygen conditions, without changing the charge carrier mobility. Light-sensitive characteristics were also observed. Additionally, this solution-processed, highly crystalline organic semiconductor can be used in high-performance organic electronic circuits as well as in gas or light sensors.

Wire density for a wetted-wire column

Arrays of vertical parallel wires (‘wetted wires’) are a promising alternative to industrial columns such as spray, tray, or packed columns. Yet, further research is required to optimize their performance and competitiveness against packed columns. This work investigates the maximum wire density using the minimum pitch (center-to-center wire distance). Results show that the pitch can be smaller than two millimeters, which is significantly less than the minimum pitches recommended in the literature. Results are discussed for liquid flow rates, wire diameters, and counter-current gas velocities. The minimum pitch is often less than the diameter of the drops due to a bead-passing phenomenon. An analytical model illustrates the pressure drop characteristics of wetted-wire columns compared to existing packings. This model shows that wetted-wire columns including those with small pitches have very low pressure drops. However, this model also shows that packing factors do not adequately describe wetted-wire columns. This implies that gas-side fluid dynamics of wetted-wire columns are fundamentally different from the gas-side fluid dynamics of packed columns.

Desain Dan Implementasi Transformator Satu-Fasa Dry-Type Dengan Pendekatan Core Geometry

Energy is one of the most important needs for humans to support daily life, especially for developing countries such as Indonesia. One of the energies needed in human life is electrical energy. For this reason, innovation was developed, namely a dry-type Single-Phase Transformer with a core geometry approach developed in the AL 1.01 building of the State Polytechnic of Malang. Calculations performed on the tool are to calculate the value of windings per volt (GPV) and the number of primary and secondary windings. Its manufacture uses a toroid-shaped transformer core. The core specification of the transformer is an outer diameter of 15cm, then an inner diameter of 5.8 cm, and a height of 7cm. The toroid transformer core that will be used is previously isolated from the transformer first to avoid leakage current which can cause heat in the transformer core. The density of the email wire from the transformer winding both from the primary and secondary windings will affect the performance of the transformer, the more tightly the email Wire is wrapped in the transformer core, the vibration generated from the transformer will be smaller, this will affect the voltage losses later in the transformer testing phase carried out using different beaban, each load changes the efficiency of the transformer that has been made will also change, this is because each load tested has different factors.

Influence of filament number and size on the basic properties of in situ made MgB2 wires

Monel-sheathed MgB2 wires with 6, 18 and 54 filaments of diameter 0.83 mm manufactured by Sam Dong Co., Ltd, have been subjected to twisting, drawing and rolling and measurements at low temperatures. R(T), I–V characteristics, critical currents and stress/strain tolerances of these wires were analyzed. Low reduction of critical current (⩽10%) by twisting between 50 mm and 12.5 mm was observed, especially for the wire with 54 filaments, which also showed the best strain tolerance to tension, ∼0.43% at 4.2 K. The engineering current density of the 18-filament wire was decreased by 56% by drawing from 0.83 mm to 0.4 mm, but improved by ∼24% by rolling from 0.83 mm to 0.64 mm. A small uninsulated coil was made from wire flattened from 0.83 mm to 0.64 mm by the wind and react process, resulting in a very high winding packing factor of 0.91 and also a high winding current density of 104 A cm−2 at B ⩽ 5.6 T. The presented properties are interesting for possible applications of these MgB2 wires in DC windings.

A Lorentz Force EMAT Design with Racetrack Coil and Periodic Permanent Magnets for Selective Enhancement of Ultrasonic Lamb Wave Generation

This article proposes an electromagnetic acoustic transducer (EMAT) for selectively improving the purity and amplitude of ultrasonic Lamb waves in non-ferromagnetic plates. The developed EMAT consists of a racetrack coil and a group of periodic permanent magnets (PPMs). Two-dimensional finite element simulations and experiments are implemented to analyze the working mechanism and performance of the PPM EMAT. Thanks to the specific design, the eddy currents increase with increasing wire density and the directions of the magnetic fields and Lorentz forces alternate according to the polarities of the magnet units. Wires laid uniformly beneath the magnets, and the gaps between adjacent magnets generate tangential and normal Lorentz forces, resulting in-plane (IP) and out-of-plane (OP) displacements, respectively. The constructive interference occurs when the wavelength of the generated Lamb wave is twice the spacing of the magnets, leading to large amplitudes of the targeted ultrasonic Lamb waves. Therefore, the PPM EMAT is capable of generating pure symmetric or antisymmetric mode Lamb waves at respective frequencies. The results prove that the developed PPM EMAT can generate pure either S0 or A0 mode Lamb waves at respective frequencies. The increase in wire width and wire density further increases the signal amplitudes. Compared with the case of conventional meander-line-coil (MLC) EMAT, the amplitudes of the A0 and S0 mode Lamb waves of our PPM EMAT are increased to 880% and 328%, respectively.

Negative Photo-Definable Polyimide Dry Films for Fine and High Aspect Ratio Patterning

We newly developed a negative photo-definable polyimide dry films with higher photoreactivity than conventional ones. We succeeded in fine and high aspect ratio patterning with 90 μm thickness and 8 μm width by using new polyimide dry films. When compared after curing, the tensile breaking strength and share strength of new and conventional polyimide dry films were almost the same. However, when compared after PEB and exposure, the new ones showed clearly higher properties than conventional one. Using this polyimide dry film as an inter-layer dielectrics or a permanent resist was effective in improving the wiring density of electric devices.

An Accurate Calculation Method of Leakage Inductance of High-Frequency Transformer With Litz Wire Winding Considering Irregular Region

The leakage inductance of a high-frequency transformer affects the operating mode and performance in dc/dc converters, so it is necessary to calculate the leakage inductance accurately. In the existing analytical calculation methods of leakage inductance of high-frequency transformers with Litz wire winding, the nonarea-equivalent high-frequency analytical method is applied to calculate leakage inductance. However, the calculated leakage inductance value is lower than its actual value due to the neglect of the irregular region between turns. In order to improve the calculation accuracy, this article proposes an analytical calculation method of leakage inductance for the high-frequency transformer with Litz wire winding, which considers the irregular region between turns. The 2-D magnetic field distribution in the transformer window and attenuation caused by high-frequency effects on magnetic field energy are analyzed and applied in this proposed method, to take the energy stored in the irregular region between turns into account indirectly. Thus, the proposed analytical expression for leakage inductance is derived correspondingly. Finally, the accuracy of the proposed method is verified by simulations and experiments. The results indicate that the relative error of calculating leakage inductance can be reduced from 16.25% to 3.79% by the proposed method within a certain range of wire densities.

Wire Length Formulation Using Wire Density, Volume and Weight for Hand Calculation and Verification of Wire Usage

Wire Bonding process uses precious materials such as gold, silver, and copper wires to create a connection from the die to the strip and completing the circuitry of a semiconductor unit. Wire consumption is identified by length that is consumed per unit and higher consumption leads to inflated cost of the product. Upon unit processing, the standard wire consumption per unit is 0.036 meters equivalent to 27800 units per 1000 meters spool but only produced 26900 units. The study focuses on validation of the possible cause of lacking 800 units equivalent to 32 meters of wire length. Using the gold wire density, volume, and weight of the wire, wire length is formulated that can be used for hand calculation and verification of actual wire length. Methodology used for validation resulted that the actual unit consumption for wire length is at 0.037 meters which lacks 0.001 meter per unit, and this is equivalent to approximately 800 units per 1000-meter spool. In parallel, supply is compliant with the 1000 meters of wire per spool. Through the results collected, it was concluded that the standard is not sufficient to be the reference for the actual wire consumption resulting to the impression of high wire consumption. It was recommended for the alignment of the standards with the actual validation using the methodology stated on the study and hand calculation using wire length formula.

A Finite Element Investigation on Material and Design Parameters of Ventricular Septal Defect Occluder Devices.

Background and Objective: Ventricular septal defects (VSDs) are the most common form of congenital heart defects. The incidence of VSD accounts for 40% of all congenital heart defects (CHDs). With the development of interventional therapy technology, transcatheter VSD closure was introduced as an alternative to open heart surgery. Clinical trials of VSD occluders have yielded promising results, and with the development of new material technologies, biodegradable materials have been introduced into the application of occluders. At present, the research on the mechanical properties of occluders is focused on experimental and clinical trials, and numerical simulation is still a considerable challenge due to the braided nature of the VSD occluder. Finite element analysis (FEA) has proven to be a valid and efficient method to virtually investigate and optimize the mechanical behavior of minimally invasive devices. The objective of this study is to explore the axial resistive performance through experimental and computational testing, and to present the systematic evaluation of the effect of various material and braid parameters by FEA. Methods: In this study, an experimental test was used to investigate the axial resistive force (ARF) of VSD Nitinol occluders under axial displacement loading (ADL), then the corresponding numerical simulation was developed and compared with the experimental results to verify the effectiveness. Based on the above validation, numerical simulations of VSD occluders with different materials (polydioxanone (PDO) and Nitinol with different austenite moduli) and braid parameters (wire density, wire diameter, and angle between left and right discs) provided a clear presentation of mechanical behaviors that included the maximal axial resistive force (MARF), maximal axial displacement (MAD) and initial axial stiffness (IAS), the stress distribution and the maximum principal strain distribution of the device under ADL. Results: The results showed that: (1) In the experimental testing, the axial resistive force (ARF) of the tested occluder, caused by axial displacement loading (ADL), was recorded and it increased linearly from 0 to 4.91 N before reducing. Subsequent computational testing showed that a similar performance in the ARF was experienced, albeit that the peak value of ARF was smaller. (2) The investigated design parameters of wire density, wire diameter and the angle between the left and right discs demonstrated an effective improvement (7.59%, 9.48%, 1.28%, respectively, for MARF, and 1.28%, 1.80%, 3.07%, respectively, for IAS) for the mechanical performance for Nitinol occluders. (3) The most influencing factor was the material; the performance rose by 30% as the Nitinol austenite modulus (EA) increased by 10,000 MPa. The performance of Nitinol was better than that of PDO for certain wire diameters, and the performance improved more obviously (1.80% for Nitinol and 0.64% for PDO in IAS, 9.48% for Nitinol and 2.00% for PDO in MARF) with the increase in wire diameter. (4) For all of the models, the maximum stresses under ADL were distributed at the edge of the disc on the loaded side of the occluders. Conclusions: The experimental testing presented in the study showed that the mechanical performance of the Nitinol occluder and the MARF prove that it has sufficient ability to resist falling out from its intended placement. This study also represents the first experimentally validated computational model of braided occluders, and provides a perception of the influence of geometrical and material parameters in these systems. The results could further provide meaningful suggestions for the design of biodegradable VSD closure devices and to realize a series of applications for biodegradable materials in VSD.

Influence of the precursor powder composition on the microstructure and the critical current density of Bi2212 wires

Influence of the precursor powder composition on the microstructure and the critical current density of Bi2212 wires