Copper Wire Research Articles

Three-dimensional representative modelling for fretting wear and fatigue of submarine power cable conductors

Submarine power cables (SPCs) for floating offshore wind turbines (FOWT) have received relatively little attention compared to the structural design of wind turbines. This is particularly true for the assessment of fretting-related damage in multi-strand copper wire conductors, due to the complexity of the contact interactions and potentially severe dynamic loading. In this paper, a three-dimensional representative crossed cylinder methodology is introduced to identify potential inter-wire fretting damage. The approach is based on a global–local methodology for FOWTs. Fretting wear testing of crossed cylinder copper specimens are used to characterise the friction and wear behaviour and validate the local fretting wear simulation. A multiaxial wear-fatigue methodology is implemented in conjunction with the global–local methodology for prediction of effects of normal operating and extreme floating wind SPC design load cases. It is shown that gross slip wear has a beneficial effect on predicted fatigue life by about two to three orders of magnitude. The work demonstrates a global–local modelling methodology for design of SPC conductors in floating wind applications.

Model-based closed-loop process control for the manufacturing of hairpin coils

As a consequence of the increasing market share of hybrid and all-electric mobility solutions, there is a need for robust manufacturing technologies that enable the efficient production of powerful electric traction motors in automotive industry. In the context of high-quality distributed stator windings, the so-called hairpin technology already meets the automotive demand regarding productivity – but process reliability is still limited by variations in the mechanical and geometric properties of the enameled rectangular copper wire leading to different springback effects within the forming processes. Against this background, a model-based closed-loop process control for the sequential tool-bound bending of hairpin coils is introduced and validated in this paper.

Cost-effective fabrication of a high-conductivity copper electrode for heterojunction solar cells via laser-induced selective metallization.

Replacing expensive silver with inexpensive copper for the metallization of silicon wafer solar cells can lead to significant reductions in material costs associated with cell production, but the susceptibility of the Cu material to oxidation remains a challenging issue to solve. In this study, we investigate copper metallization of Indium Tin Oxide surfaces to define copper grid electrodes for heterojunction cells. We propose a novel laser-induced selective metallization (LISM) method to fabricate large-scale copper electrodes for heterojunction solar cells at low cost. This study includes a comprehensive evaluation of the morphological characteristics and electrical properties of the electrodes. The effects of laser parameters on the morphology, composition, size, and conductivity of copper electrodes are investigated. The goal of establishing the process window is to obtain the optimal laser parameters for manufacturing highly conductive copper electrodes. These optimized parameters will then be employed to fabricate high-performance electrodes for solar cells. Furthermore, a detailed analysis of the mechanism underlying laser selective metallization is provided. The resulting Cu electrodes exhibit high conductivity and low resistivity of 1.98 × 10-5Ω.cm, demonstrating the potential of this method for efficient and cost-effective solar electrode production.

Harnessing Plant Bioelectricity through Prickly Pear as Botanical Batteries

Plants which are essential for life, have the potential to become a renewable energy source in the Future. They can generate electricity, reducing greenhouse gas emissions and being environmentally friendly. This study aims to explore the untapped potential of botanical batteries and contribute to green energy technology. Plants' capacity to convert sunlight into chemical energy could be a viable and environmentally friendly source for electrical power generation, offering a sustainable solution to the world's growing energy demands while mitigating climate change impacts. To achieve the goal of the study, pure experimental research was applied. And the researchers used cactus (prickly pear), copper nails, zinc nails, copper wire, alligator clips, and disposable plastic containers. The study was conducted at Bayugan National Comprehensive High School, Bayugan City. Throughout the analysis of the data obtained after the three tests conducted, it has been found that like an electrochemical cell, copper and zinc electrodes inserted into prickly pear leaves can generate energy. With the highest current magnitude and maximum value at the highest contact area, the prickly pear plant has the highest potential for energy harvesting. Cut-off or partially leaved leaves can be harvested for their energy, which can then be utilized to charge batteries or power low-power devices.

Copper-Enriched Nanostructured Conductive Thermoelectric Copper(I) Iodide Films Obtained by Chemical Solution Deposition on Flexible Substrates

The objects of our research are flexible thin-film thermoelectric materials with nanostructured CuI layers 0.5–1.0 μm thick, fabricated by the chemical solution method Successive Ionic Layer Adsorption and Reaction (SILAR) on flexible polyethylene terephthalate and polyimide substrates. These cubic γ-CuI films differ from films obtained by other chemical solution methods, such as spin-coating, sputtering, and inject printing, in their low resistivity due to acceptor impurities of sulfur and oxygen introduced into CuI from aqueous precursor solutions during SILAR deposition. Energy barriers at the boundaries of 18–22 nm CuI nanograins and a large number of charge carriers inside the nanograins determine the transport properties in the temperature interval 295–340 K characterized by transitions from semiconductor to metallic behavior with increasing temperature, which are typical of nanostructured degenerate semiconductors. Due to the resistivity of about 0.8 mΩ· m at 310 K and the Seebeck coefficient 101 μV/K, the thermoelectric power factor of the CuI film 1.0 μm thick on the polyimide substrate is 12.3 μW/(m · K2), which corresponds to modern thin-film p-type thermoelectric materials. It confirms the suitability of CuI films obtained by the SILAR method for the fabrication of promising inexpensive non-toxic flexible thermoelectric materials.

Advancing rehabilitation: Knittable fiber-shaped sensors for monitoring rotator cuff injury recovery

The integration of sensors into clothes offers significant convenience for monitoring the rehabilitation of patients. However, conventional flat sensors face challenges in achieving seamless integration due to their incompatibility with clothing. Here, we created a knittable fiber-shaped capacitive pressure sensor designed for long-term monitoring of shoulder movements of patients with rotator cuff injuries. This innovative sensor incorporates copper wires and silver conductive fibers as electrodes, with a polyvinylidene fluoride (PVDF) composite fiber membrane containing zeolite imidazolate framework (ZIF-8) particles as the dielectric layer. The resultant sensor can be seamlessly while non-invasively incorporated into the garment of patents due to its exceptionally flexibility. After optimizing the number of Cu wires (4) and electrospinning time of PVDF (8 min), the knittable sensor showed a sensitivity of 0.04 kPa−1 in the range of 2–8 kPa, 10 times higher than that without ZIF-8 (0.003 kPa−1). Beyond its applications in monitoring shoulder movement across various directions and degrees, this sensor has proven its ability in monitoring breath or recording weight when encompassed into a mask or a carpet, respectively. Via integrated in daily wearings, this sensor holds immense potential in the fields of rehabilitation monitoring and personal health management due to its remarkable sensitivity and flexibility.

Study of the copper structure samples externed to extreme influences

This work is devoted to the study of changes in the crystal structure, chemical and phase composition of copper samples subjected to extreme effects of temperature, pressure and electromagnetic fields. With the help of X-ray diffraction, as well as microanalysis, it was revealed that the plastic deformation of copper wires in the car power supply system leads to the formation of a superconducting Cu2O phase. This is the reason for the rapid ignition of the car, as it leads to a sharp increase in the magnitude of the electric current and temperature in the plastic deformation zone of copper wires. During explosion welding of copper samples, the Cu2O phase appears on their surface, which has superconducting properties. This significantly changes the electrophysical properties of copper samples. In metallurgical processes during the smelting of copper products, there is a possibility of the appearance of a superconducting Cu2O phase. When modifying a copper melt with hardening additives, the superconducting Cu2O phase makes it possible to obtain fracture-resistant copper products with high electrical conductivity. Plastic deformation of a copper foil 30 mkm thick by a magnetic field generated by a current of 180 kA leads to the formation of a texture and rupture of the foil. This has been detected using X-ray diffraction, as well as optical and scanning electron microscopy.

Implementation of a Rogowski coil prototype for the measurement of alternating electric current

This article aims to present the development of a Rogowski Coil prototype for the measurement of alternating electric current up to 80Arms. For this elaboration, circular hose, ABS filament and enamelled copper conductor was used. In addition, an Arduino and an AD620 instrumentation amplifier were used for data acquisition. The results were satisfactory, because the average percentage of errors corresponded to approximately 1.75%.

Innovating in-situ characterization: a comprehensive measurement system for measuring the ZT and the contact resistance of vertical thermolegs exploiting the vertical transfer length method

In order to optimize their system design and manufacturing processes, it is crucial to undertake a thorough electrical and thermal characterization of micro thermoelectric generators (µTEGs). To address this need, a highly advanced and fully integrated in-situ measurement system has been developed. The main objectives of this system are to (1) enable the measurement of ZT and thereby of all thermoelectric (TE) properties of thermolegs made from powder-based TE materials and (2) at the same time accurately measure the contact resistance between the TE material and the electrical contacts. The µTEG fabrication concept used in this study is based on copper-cladded printed circuit board (PCB) material as a substrate, using the Cu layers for easy contact formation. In a first step, an innovative measurement concept, based on a distinctive vertical rendition of the well-established transfer length method, has been realized, allowing for the in-situ measurement of contact resistance between the TE material and the copper conductors on the PCB substrate. This enables a comprehensive assessment of the impact exerted by the applied force and temperature during e.g. a hot-pressing step for compacting the powder-based thermolegs during the manufacturing process. In a second step, a comprehensive measurement platform, referred to as the ZT-Card, has been devised to facilitate the evaluation of all relevant TE material properties—Seebeck voltage, electrical conductivity and thermal conductivity (all measured in vertical cross-plane orientation)—inherent to a highly miniaturized thermoleg. Additionally, the ZT-Card also allows for the assessment of contact resistance between the copper contacts and the TE material. Successful testing of this measurement system inspires confidence in the capabilities of the platform and will aid in future µTEG development.

The Influence of Glass Fiber and Copper Wire z-Binder on the Mechanical Properties of 3D Woven Polymeric Composites

AbstractThree-dimensional composites (3D) have potential applications in various fields due to their enhanced properties compared to conventional two-dimensional composites (2D). This study investigates the effect of different volumes of z-binder made from copper wire and E-glass fiber on the mechanical properties of 3D woven polymeric composites. The tensile, flexural, and fracture toughness behavior of four types of 3D orthogonal woven composites were studied in addition to a comparative 2D composite. The creation of the 3D orthogonal single-ply fabrics involved weaving z-binders using two different copper wire diameters, single fiber bundles, and double fiber bundles, each combined with four layers of woven E-glass fiber. The consolidation process for both 2D fabric and single-fabric 3D woven composites was executed using the hand lay-up technique. The results showed that most 3D woven composites outperformed 2D composites in terms of fracture toughness (stress intensity factor KIC and energy release rate GIC) and flexural strain. However, a decrease in flexural strength and tensile properties was observed for all 3D composites. The specimen with a small copper diameter had the smallest decrease of 5% in tensile strength. Furthermore, a decrease of 9% and 21% was attained by reinforcing with double and single glass fiber bundle z-binders, respectively, as compared with 2D composites. The highest enhancement of 92.5% in flexural failure strain was attained with double glass fiber bundles of z-binder. The maximum improvement in KIC fracture toughness, reaching 126% and 101.5%, was observed in specimens with a single glass fiber bundle z-binder and those with a large copper wire diameter, respectively.

Integrated coplanar waveguide coil on diamond for enhanced homogeneous broadband NV magnetometry.

Nitrogen-vacancy (NV) centers in diamond have emerged as promising quantum sensors due to their highly coherent and optically addressable spin states with potential applications in high-sensitivity magnetometry. Homogeneously addressing large ensembles of NV centers offers clear benefit in terms of sensing precision as well as in fundamental studies of collective effects. Such experiments require a spatially uniform, intense, and broadband microwave field that can be difficult to generate. Previous approaches, such as copper wires, loop coils, and planar structures, have shown limitations in field homogeneity, bandwidth, and integration in compact devices. In this paper, we present a coplanar waveguide (CPW) gold coil patterned on a 3 × 3 mm 2 diamond substrate, offering full integration, enhanced stability, and broad bandwidth suitable for various NV sensing applications. Coil fabricated on diamond offers several advantages for magnetometry with NV centers ensemble, including enhanced heat dissipation, seamless integration, scalability, and miniaturization potential. We optimize critical geometrical parameters to achieve a homogeneous magnetic field with a coefficient of variation of less than 6% over an area of 0.5 mm 2 and present experimental results confirming the performance of the proposed CPW coil.

A new deformable self-clinching fastener

This work proposes a novel deformable self-clinching fastener for producing hidden lap joints suitable for both structural and electric power distribution applications. The fastener, characterized by an axisymmetric concave shape, is employed to fabricate hybrid busbar joints between electrically conductive strips of different materials and thicknesses. The self-clinching process with the new deformable fastener involves machining dovetail holes in both conductors and applying a squeezing force to the fastener to create a form-closed mechanical joint. The work encompasses both experimental investigations and numerical modeling using finite element analysis and is carried out on unit cells made from aluminum and copper conductors, which are representative of the joining process. The investigation evaluates force requirements, conducts destructive testing, and performs thermo-electric characterization of the new joints to conclude on the suitability of the new deformable self-clinching fastener for electric power distribution applications. Results indicate that while copper fasteners necessitate greater squeezing forces, they offer superior mechanical and thermo-electrical performance compared to aluminum fasteners in hybrid busbar joints.

A pipe arrangement structure triboelectric nanogenerator for mechanical energy harvesting and sports training monitoring

Recently, intelligent wearable sensors applied in the field of smart sports have attracted much attention. Hence, we designed a pipe arrangement structure triboelectric nanogenerator (PA-TENG), and it can obtain mechanical energy and monitor sports motion. The triboelectric materials are composed of a polydimethylsiloxane layer attached to a silicone tube and nylon layer. The conductive copper attached to the silicone tube surface serves as a conductive electrode of the PA-TENG. Meanwhile, the soft silicone tube can endow the PA-TENG device with the ability to sense pressure. The results indicate that this silicone tube substrate can effectively adsorb conductive copper layers, and the conductive electrode layer still maintains good conductivity stability at different bending angles (15°–90°). The PA-TENG can achieve the maximum output power of 1.03 mW (matched load: 6 MΩ). The results indicate that the PA-TENG can attain the open-circuit voltage (Voc) of 190.05 V and the short-circuit current (Isc) of 1.98 μA. The transfer charge (Qsc) of the PA-TENG can arrive at 139.01 nC. The PA-TENG can drive the light-emitting diodes (LEDs), which demonstrates good practicality. Moreover, the PA-TENG can be installed on human joints (fingers, arms, knees, feet, etc.) as a monitoring sensor for various sports training, providing real-time sensing data for training. This research provides a novel pipe arrangement substrate for the wearable sports training sensor.

Mechanism of Seebeck coefficient variation at the output of NiCr/NiSi thin film thermocouple with different wires

In this paper, by using magnetron sputtering to prepare NiCr/NiSi thin film thermocouples, the static calibration method is used for NiCr/NiSi thermocouples with rapid temperature calibration experiments. Different temperature calibration curves are obtained. The Seebeck coefficient of NiCr/NiSi thin film thermocouples connected to NiCr/NiSi wires is significantly higher (41.39 μV/°C) than that of NiCr/NiSi wires (0 μV/°C). The Seebeck coefficient (41.39 μV/°C) of the NiCr/NiSi thin-film thermocouple connected to copper wire is significantly higher than that of the thermocouple connected to copper wire (0 μV/°C). The problem of the Seebeck coefficient of the K-type thermocouple is analyzed by experimental data, which provides the relevant parameter basis for the use of the K-type thermocouple. The method has the advantages of simple equipment, convenient operation, accurate and reliable data, and provides a basis for the sensor to measure the temperature measurement.

Investigation and Comparison of Different Calculation Methods for AC Copper Loss of Flat Copper Wire in Axial Flux Permanent Magnet Motor

Investigation and Comparison of Different Calculation Methods for AC Copper Loss of Flat Copper Wire in Axial Flux Permanent Magnet Motor

The specific current action integral for conductors exploded by high-frequency currents

The explosive emission processes that occur at electrode surface microprotrusions may have harmful effects in a variety of electrodynamic and acceleration systems exposed to high-power radio frequency electromagnetic waves. This paper presents the results of a radiative magnetohydrodynamic simulation of the explosion of copper conductors that occur under conditions inherent in the explosion of electrode microprotrusions, i.e., at current densities of the order of 109 A/cm2. Explosions occurring under quasi-stationary and radio frequency conditions (hereinafter referred to as quasi-stationary and radio frequency explosions, respectively) were considered. It was shown that in all the considered cases, the explosion occurred at high temperatures, so that the energy deposited in the conductor by the time of explosion exceeded the sublimation energy of the conductor material. It turned out, however, that the energy deposited in the conductor under radio frequency conditions, regardless of the frequency of current oscillations, was more than two times less than that deposited under quasi-stationary conditions. The explosion time was also virtually independent of the frequency, and it was approximately three times longer than that calculated for quasi-stationary conditions. For a radio frequency explosion, the specific current action integral was somewhat less (by about 25%) than that for a quasi-stationary explosion, and its value was actually independent of frequency. At the same time, in the radio frequency regime, the radiation power coming out of the conductor substance drops strongly, and it is almost two orders of magnitude smaller compared to the radiation power in the quasistationary regime.

Next Level of 1/1 μm Line and Space Copper Redistribution Layer Fabrication with Organic Dielectric Materials

An electrical reliability of fine copper redistribution layer (RDL) with 1/1 μm line and space fabricated by using positive photosensitive polyimide (PSPI) has been demonstrated. The polyimide containing flexible molecular units in PSPI was introduced, in assumption to increase the entanglement of each polymer chain with a design concept of polymer backbone to enhance mechanical and thermal reliability. To conduct a series of tests, test vehicles with semi-additive copper RDL with 1/1 μm line and space were fabricated with Toray’s PSPI for electrical reliability test. Through a series of electrical reliability tests utilizing our test vehicles, PSPI out-performed the phenol-based resin, which has been proven to have excellent mechanical and thermal stabilities when compared with other resins. 1/1 μm line and space electrodes after electrical reliability tests were also observed and cross-sectioned. The observation of electrodes clearly showed oxidation-reduction of the electrodes on anode and cathode, respectively. On the cathode, copper particles of several nm in diameter were formed on the PI film surrounding the copper wiring. On the anode, copper oxide layers of about 100 nm thickness were observed on the copper wiring surface, which turned out to be Cu2O when analyzed with Electron Energy-Loss Spectroscopy (EELS) measurement.

Analysis of the Surface Matrix of Copper Cable in Jointing as the Effect of Increasing Current and Heating on Fire Application

This research aims to analysis of the surface matrix of copper cable in jointing as the imfluence of increasing current and heating on fire experiment. The investigation makes it easier to observe parts of its material of the surface matrix changes of copper cable in jointing as increasing of heating. The study was observed the material surface of general requirements for electrical installations (PUIL) jointed cables and standard NYA ø 1.5 mm2 cables at current load of 50 A and 110A using HIROX digital microscope, XRF (X-ray fluorescence), Raman spectroscopy, and fluke infrared thermometer (FLIR). The results of the study were obtained that the PUILsample jointing heat cable reached of 201oC and 1087oC with heat standard cable of 25.6oC. The copper cable will melt when the cable reached in over heating of 1080oC that it caused the deformation of the cross-sectional area of the cable which are observed in changes in the surface matrix of the burned cable structure. This research can be used as scientific basic for inverstigating the caused of fires and the heat maximum application on the cables.

Exploration of Interfacial Materials Chemistry Control to Improve Cu Wire Bonding Reliability

Copper wire bonding, with its advantages of higher electrical conductivity and better mechanical strength, has replaced gold wire bonding as a proven cost-effective electrical interconnection solution for IC packaging for the past 15 years. Early development of Cu wire bonding required overcoming of several technical challenges including bond pad damage caused by copper’s hardness and brittleness relative to gold. A more chemistry related challenge of using Cu as bonding wire is its well-known reactivity with oxygen. Inert atmospheric envelope of forming gas surrounding bonding capillary was developed to prevent oxidation of Cu wire during electronic flame off to enable a strong bonding. Another more elusive materials-chemistry related reliability challenge, with a typical low ppm occurrence, has been the chloride-induced corrosion defects between the Cu wire and Al bond pad. The opportunistic low-level chloride contaminations can originate from various points of packaging manufacturing process flow and often render it un-trackable. In this talk, we present recent efforts to systematically control interfacial materials chemistry across Cu bonding wire, Cu/Al bimetallic contacts and CuxAly intermetallic compounds with the aim to eliminate corrosion defects and improve the overall bonding reliability. The current prevailing manufacturing solution is to utilize Pd-coated Cu bonding wire that can only partially mitigate the CuxAly intermetallic corrosion vulnerability. We utilized a real-time corrosion screening metrology to explore the underlying interfacial materials chemistry drives vigorous corrosion between Cu wire and Al bond pad when exposed to trace level of chloride contaminant. Combining with SEM, sensitive infrared spectroscopy and electrochemical characterization, our data show strategic surface modification on both Cu bonding wire and exposed CuxAly intermetallic can have a significant impact on reducing corrosion defect rates. The obtained mechanistic insights provide several new strategies enabled by a novel Cu-selective passivation coating technology to effectively mitigate Cu wire bonding corrosion defects. Implications on further improving overall Cu wire bonding reliability will be present based on these new approaches that have low-cost and packaging friendly advantages.

An increase in electrical burns during the covid lockdown in Western Cape, South Africa

BackgroundA severe Covid lockdown in South Africa may have changed burn patterns due to the downturn of the economy and stay-at-home policies. We describe the volume and type of burn admitted to a tertiary hospital before and during the Covid lockdown. Materials and methodsThis was a retrospective study from before (April 2019-March 2020) and during (April 2020-March 2021) the Covid pandemic. Patient demographics, burn etiology, and clinical outcomes were described. Logistic regression was used to model associations between burn etiology and the Covid period. ResultsOf 544 burns, 254 (46.7%) occurred before and 290 (53.3%, p = 0.051) during Covid. The proportion of electrical burns doubled during Covid n = 20, 32.3% vs n = 42, 67.7%, (p = 0.053) periods. At least half were associated with suspected cable or copper theft. On multivariate analysis, flame burns (OR=2.42, p < 0.001), electrical burns (OR=4.88, p < 0.001), and paying patients (OR=4.21, p < 0.001) were more likely to be associated with the Covid period. ConclusionElectrical burns doubled during Covid, potentially related to an increase in cable and copper wire theft, a phenomenon described during hard economic times in other settings. More studies to understand this potential relationship are indicated to prepare burn centers during future pandemics and/or economic hardship.