Copper Traces Research Articles

Study on the interface mechanism of copper migration failure in solder mask-substrate package

Microelectronic packaging technology is developing towards a complex structure with finer routing layers, which will bring great challenges to the reliability of microelectronic packaging. The failure caused by the migration of trace on devices in high temperature and humidity environment is especially serious. Today, there is still a lack of detailed research on the effect of interface mechanism of stacked material on copper migration. In this paper, for more investigation of interface mechanism, two types of solder mask (SM) material with different characteristics, AUS 320 and AUS SR1, were used for comparative experiments. The interface mechanism of stacked material during copper migration was studied based on commercial Flip Chip-Chip Scale Package (FC-CSP) by Biased Highly Accelerated temperature and humidity Stress Test (B-HAST). The characteristics of interface bonding of the two types of solder mask-substrate bi-material samples were discussed in detail by analyzing the failure mode and characterizing migration sites. The study shows that material interface affects physical mechanism of failure, which shows different failure modes of migration of copper trace along the interface micro-cracks under bias. The research results can provide theoretical basis and experimental support for the study of reliability of packaging device.

Parasitic Capacitance Associated With Inductive Sensors Used in MIT Imaging

Magnetic induction tomography (MIT) has recently been accomplished using a single inductive sensor, but under the assumption that it behaves as an ideal inductor. When performing a scan with a sensing coil that typically consists of a collection of concentric circular printed circuit board (PCB) copper traces connected in series, small amounts of parasitic capacitance arise that contribute to measured tank circuit loss. Results of this work quantify the magnitude of parasitic capacitance and associated losses. For current inductive sensors, capacitance-related loss is shown to diminish considerably when the coil is positioned more than ~2 cm from a target boundary. Recognizing that single-coil MIT scans generally position the coil within 2 cm of a target boundary, a correction is proposed, which enables a more accurate measurement of true inductive loss. Previously published scan data over agarose phantoms are then reexamined to show the negative impact on imaging fidelity that results when capacitance-related losses are ignored. Image comparisons are made using full 3-D image reconstruction, demonstrating that failure to compensate for parasitic capacitance loss can degrade image fidelity.

Novel fluxing strategy of copper matte smelting and trace metals in E-Waste recycling

The distribution behavior of trace metals between copper matte and spinel-saturated iron silicate slags was investigated at 1250 °C and pSO2 of 0.25 atm at low silica concentrations. The experiments were conducted in magnetite (Fe3O4) spinel crucibles in controlled CO-CO2-SO2-Ar gas mixtures using a high-temperature equilibration-quenching technique. The concentrations of trace elements in matte, spinel, and slag were quantified by electron probe X-ray microanalysis and laser ablation-inductively coupled plasma-mass spectrometry. The trace metals (Ag, Ni, Co, and Sn) in all phases and their distribution coefficients were calculated as a function of matte grade. Results show that silver and nickel can be effectively recovered into matte, whereas cobalt and tin are predominantly deported into slag and gas phases, respectively. These results augment the fundamental thermodynamic data of trace metal distributions in copper smelting processes at low-silica fluxing practices.

Vacuum formed coils for MRI.

To describe a digital fabrication method used for custom MRI receive coils with vacuum forming and electroless copper plating. Our process produces intricate copper traces on curved surfaces. A three-dimensional scan of a desired anatomy is obtained and used to design coil elements. The layout is predistorted with a self built simulation of the vacuum forming process and the geometric overlaps are tested with electromagnetic simulation software. The desired coil geometry is patterned onto a polycarbonate sheet by sandblasting through a tape mask. The sandblasted areas are then catalyzed with a palladium-tin solution and vacuum formed. The catalyzed, three-dimensional part is placed into a custom built plating tank and copper plated. Electronic components are attached to the copper traces to form resonant receive coils. The methods described here are demonstrated and tested with an 8 channel visual cortex coil array. The prototype coils exhibit quality factor ratios higher than three, indicating body noise dominance. The coil array shows high signal-to-noise ratio (SNR) near the periphery of a head shaped phantom. In vivo images with up to spatial resolution were acquired on a human volunteer. This work presents the first example of vacuum formed coils with direct electroless copper plating. Our fabrication method results in coil arrays that are in close proximity to the body. This methods described here may enable the rapid development of a set of coils of different sizes for applications including longitudinal fMRI studies and MR-guided therapies.

Polarimetric Microwave Sensor for Angular Speed Measurement

This article presents a design methodology and prototyping of an angular speed sensor based on microwave polarimetry. The detection mechanism relies on the transmission response of a dual-polarized circular aperture irradiating an array of regularly spaced copper traces printed on a PCB. The generated response is a regular pulse train defined by the location of the copper trace with reference to the center of the circular aperture. While the angular speed sensor can be sampled at any rate and for any time length, the detector response was acquired within a 1-s duration with the circular aperture response effectively sampled at 10 kHz for demonstration purposes. The acquired response was analyzed in the frequency domain using the fast Fourier transform (FFT) and the rotor speed was obtained from the frequency spectrum of the acquired pulse train. To demonstrate the working principle of the detection system, the printed PCB rotor, which occupies an area of 84.64 cm2, was attached to a rotary stage set to rotate at certain angular speeds, including but not limited to 62 r/min. In all the speed settings, the speeds were detected in 1 s with a worst case error of ±0.625 r/min.

Proximate composition and characterization of the vitamins and minerals of dandelion (Taraxacum officinale) from the Middle Doce River region – Minas Gerais, Brazil

This study aimed to determine the chemical composition and the vitamin, carotenoid, and mineral profile in dandelion (Taraxacum officinale) collected from the Middle Doce River region (Médio Rio Doce) in the state of Minas Gerais, Brazil. To accomplish this, the physicochemical parameters, such as titratable acidity, pH, and soluble solids were determined, in addition to the evaluation of the plants’ proximate composition (moisture, ash, proteins, dietary fibers, and lipids). The vitamin E, carotenoids and vitamin C were determined by HPLC and the minerals were analysed by inductively coupled plasma atomic emission spectrometry. The T. officinale samples presented a low content of macronutrients, a total energy value of 27.88 kcal.100 g−1 FW, a high fiber content (3.7 g.100 g−1 FW), low levels of total vitamin E (43.67 μg.100 g−1 FW), total carotenoids of 11.95 g.100 g−1 FW, and did not present vitamin C in detectable levels. The mineral analysis revealed a high concentration of iron, manganese, copper, zinc, and selenium, and small amounts or traces of aluminium, cadmium, nickel, and chromium. In conclusion, T. officinale was shown to be an important source of nutrients, especially fiber, iron and manganese.

Electrochemical enhancement of carbon black-infused poly(lactic acid) filament for additive manufactured electronic applications

Here we present an electrochemical method to enhance the electrical conductivity of commercially available, carbon-black infused polylactic acid (PLA) for use in material extrusion-based additive manufacturing (MEAM). After fabrication, the carbon-black infused PLA structure was processed in aqueous solutions consisting of either hydrochloric acid (HCl), nitric acid (HNO3), or sulfuric acid (H2SO4). This study examines the effects of acid concentration of the three types of acids, input waveform shape applied during the electrochemical process, waveform amplitude, and the frequency of the waveforms on the bonding of the negatively charged ions to the conductive PLA. We found that inputting a DC square pulse in a 7 M H2SO4 solution yielded a 51% reduction in electrical resistance. X-Ray diffraction (XRD) analysis shows that line width does shift to lower 2θ values without affecting the d-spacing and the 2θ peaks decay indicating that the ions introduced through the electrochemical doping process are being diffused into the conductive workpiece. Energy dispersive X-ray spectroscopy (EDS) showed the presence of sulfur ions located throughout the processed carbon-infused PLA, even at the core. Throughout this study, we found that this electrochemical process can create electrically in-active dead zones that occurs from higher current densities. XRD analysis reveals that peaks in these dead zones move to higher 2θ, rather than lower 2θ in the improved areas. This points to a shrinking of the lattice structure and verifies that structural changes are occurring. Electrically improved areas can be utilized in conjunction with electrically in-active dead zones to create conductive areas with insulating zones, mimicking copper traces on a PCB. This electrochemical process provides the opportunity for fused filament fabrication to be used in more electrical applications.

Erdosteine-based potentiometric sensor for real-time surveillance of copper traces in food supplements and shredded canned tuna

Industrial anthropogenic activities pollute water and contaminate fish with heavy metals. The study presented a chemically modified carbon paste sensor for Cu (II) ion assay based on Cu-erdosteine association complex. The electrode exhibited a Nernstian response (29.6 ± 0.018 mV/decade) with a wide linear concentration range (1.99 ×10−6 −1 ×10−2 mol L−1). Over the pH range of 4.0–6.0, the potentiometric response of the fabricated electrode is independent of pH. The sensor determined the Cu (II) content in drug substances, pharmaceutical formulations, and tuna meat via potentiometric titration with EDTA. The method did not differ statistically from the method described in the literature.

Effects of Dietary Supplementation of Different Levels of Zinc, Manganese and Copper Nanoparticles on Growth Performance and Bioavailability in Commercial Broilers Chicks

Background: Nanotechnology is an emerging field and it has shown the great impact in broiler sector for production. Although extensive research is needed to evaluate the safety of nanominerals. Methods: A biological study was carried to evaluate the effect of dietary supplementation of inorganic, organic and nano forms of zinc, manganese and copper trace minerals on growth performance and immune status of commercial broiler chicken out for 35 days with 150 numbers of commercial broiler chicken and randomly distributed in 5 treatment groups viz., T1 (Inorganic 100%), T2 (Organic 100%), T3 (Nano 100%), T4 (Nano 50%) and T5 (Nano 25%) comprising of 30 birds in each group. Result: The results revealed that body weight, cumulative body weight gain and feed intake of broiler chicken increased significantly (p less than 0.01) in the 50 and 100% nano trace mineral supplemented groups when compared to other groups without any significant change in FCR. T3 and T4 exhibited significant (p less than 0.05) improvement in serum superoxide dismutase activity. The mRNA expressions of biomarker gene metallothionein, manganese-superoxide dismutase and ceruloplasmin were upregulated in T3 and T4 groups revealing that the nano trace mineral supplementation had better bioavailability.

An ultrasensitive and highly selective nanomolar electrochemical sensor based on an electrocatalytic peak shift analysis approach for copper trace detection in water

Copper (Cu) sensing in the nanomolar range is an important challenge for marine water monitoring, especially with eco-friendly materials and reagents. For this purpose, electrochemical Cu(II) sensors appear as fully suitable because of their relatively high sensitivity, selectivity and adaptability for in situ measurements. So far, one of the usual electrochemical methods for Cu(II) sensing is adsorptive anodic stripping voltammetry (AdASV), since it offers a good selectivity, accumulation at open circuit potential and a reliable analytical response for concentrations above 10 nmol.L−1. Surprisingly, no work has ever addressed an electrocatalytic procedure to enhance the electrochemical copper sensing and allowed detection below 10 nM. Thus, we have developed an original two-step strategy based on the surface modification of pencil graphite electrodes (PGE) with p-aminobenzyl-C-functionalized cyclam, a strong chelating ligand for Cu(II), as well as the use of a simple reaction which can be electrocatalyzed by Cu such as HER (Hydrogen Evolution Reaction) to finally determine the accumulated amount of copper catalyst on the PGE. We show here that (i) a well-defined diffusion-limited catalytic peak can be obtained from cyclic voltammetry (CV) experiments with Cu(II)-cyclam-modified PGE, (ii) this HER peak potential is correlated to copper surface concentration, which can be sensed at the same time by adsorptive anodic stripping voltammetry and (iii) peak shift analysis (SA) of the voltammetric curves is a more sensitive method than the commonly used stripping voltammetry to reveal copper accumulation at modified PGE. Indeed, the limit of detection (LOD) reached with this method is one order of magnitude lower compared to AdASV (LOD = 1.1 nM and 16 nM, respectively). These results illustrate the ability of electrocatalysis to be a relevant tool under certain conditions for metal trace detection through SA.

Fine Pitch Flexible Printed Circuit Board Patterning for Miniaturized Endoscopic MicroUltrasound Arrays.

Microultrasound (micro-US) has become an invaluable tool for preclinical research and in emerging applications in clinical diagnosis and treatment guidance. Several such applications can benefit from arrays with a small footprint and endoscopic form factor. However, critical challenges arise in making electrical connections to array elements in such spatial constraints. In this work, we describe a method to pattern a high-density flexible circuit cabling on a copper-on polyimide film, using laser ablation of a polymer resist and wet etching, and then demonstrate a connection to a micro-US array. We investigate laser ablation process parameters and evaluate the ability to consistently pattern continuous copper traces. A minimum 30- [Formula: see text] pitch was achieved with 5- [Formula: see text]-wide electrode lines, and continuity of a 5-m-long trace is demonstrated. A flexible circuit with 30-mm-long traces with 30- [Formula: see text] line and 30- [Formula: see text] space before fan-out was fabricated to connect in an interleaved manner to a 32-element array with 30- [Formula: see text] element pitch. Metal deposition and laser ablation were used to connect and pattern the element electrodes to the copper traces of the flexible circuit. Electrical and acoustic measurements show good yield and consistent impedance across channels. Element pulse-echo tests demonstrated device functionality; the two-way pulse had 43-MHz center frequency and 40% fractional bandwidth (-6 dB). The proposed manufacturing methods facilitate the prototyping and fabrication of flexible endoscopic or small-footprint micro-US devices.

Simultaneous external and internal marking of Triatoma sordida nymphs: trace element efficacy and microgeographic dispersal in a peridomestic Brazilian Cerrado rural household

BackgroundChagas disease (American trypanosomiasis) is an important neglected tropical illness, which has the flagellate protozoan Trypanosoma cruzi as etiological agent and blood-feeding insects of the Triatominae subfamily as vectors. Despite its importance for disease epidemiology, field studies targeting microgeographic dispersal of triatomines in endemic areas are rare. The ability wingless nymphs have to move (crawl) within peridomestic settings is a key component regarding the design and development of rational control strategies.MethodsWe double-marked Triatoma sordida fourth-instar nymphs (N4) with a reliable fluorescent dye and a trace element. This new methodology allowed us to simultaneously evaluate (i) nymph dispersal and (ii) the effectiveness of copper (Cu), chromium (Cr), and cadmium (Cd) trace elements as potential new markers. In the mark-release-recapture (MRR) experiment, 390 T. sordida N4 were released in the peridomicile of a single rural household, 130 individuals at each of three release points, at distances of 2, 5, and 10 m from the chicken coop (CC) and 27, 32, and 35 m away from the horse corral (HC). All specimens were double marked (Cu/blue, Cr/orange, Cd/green). Recaptures occurred in two intervals: 1–3 days and 15–17 days after release.ResultsSpecimens were successfully recaptured at all distances up to 10 m. A total of 19, 23, and 10 specimens were able to disperse 2, 5, and 10 m, respectively, to reach the CC. No insects were recaptured at the HC. Of the three analyte/paint combinations tested, Cr/orange gave the most promising results; Cu/blue marker and Cd/green marker performed very poorly with only 4/19 and 0/10 analyte/paint ratios, respectively.ConclusionsTriatoma sordida N4 could cover a distance of 10 m in 17 days. This indicates that nymphs seem to have a reduced dispersal capability compared to adults. Ninety-one percent of the 22 recaptured orange-marked nymphs were still Cr positive after the 17-day period evaluated. This makes this analyte a good candidate for future investigations that will apply this marking method in MRR studies.Graphical

A novel fast room-temperature cloud point extraction coupled to graphite furnace atomic absorption spectroscopy for Copper(II) traces determination

ABSTRACT A novel environmentally friendly rapid cloud point extraction at room temperature coupled to graphite furnace atomic absorption spectroscopy (RT-CPE-GFAAS) for Copper (II) traces quantification was developed. Were found the most optimal conditions for the instant surfactant rich phase of Triton X-100 formation and the extraction of Copper (II) as a complex with 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium perchlorate (DHMPhB) at room temperature immediately: addition of 0.5 mol L−1 H2SO4 solution to pH 4.5; 0.15 mol L−1 ammonium benzoate; 1.5 · 10–4 mol L−1 DHMPhB and 1 v/v.% Triton X-100. As a diluent for surfactant rich phase was used 2-propanol. The calibration plot constructed under the optimal conditions is linear in the range of Copper (II) concentrations of 0.31–127 μg L−1, and the limit of quantification and limit of detection are 0.31 and 0.09 μg L−1 respectively. The developed RT-CPE-GFAAS technique was successfully used to determinate Copper (II) traces in water samples with affordable results.

Characterization of Alumina Ribbon Ceramic Substrates for 5G and mm-Wave Applications

A recently developed material technology at Corning Inc., namely, Alumina Ribbon Ceramic (ARC), is investigated as a potential substrate candidate for fifth generation (5G) and millimeter-wave (mm-wave) applications. In this article, we characterize an 80- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick ARC substrate material in the frequency range of 3–50 GHz using microstrip ring resonator (MRR) method and extract the loss of various planar transmission lines, such as microstrip and coplanar waveguide (CPW) lines on ARC substrate up to 50 GHz as well. Moreover, different test structures designed on an 80- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick ARC substrate are utilized to extract the electrical parasitics associated with a single-grounded through-alumina via (TAV) and transmission properties of ground–signal–ground (GSG) TAV of 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> diameter over the frequency range of 0.1–50 GHz. The semiadditive patterning (SAP) process is employed to metallize the top and bottom layers of ARC substrate to form the copper traces for the designed structures. Combined with the previous characterization results of a 40- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick ARC substrate in 30–170 GHz, the dielectric constant of ARC was extracted to be ~10.12 over 3–170 GHz, while its loss tangent varies in the range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.6\times 10^{-5}-1.3\times 10^{-3}$ </tex-math></inline-formula> over the same frequency band. The average measured insertion loss of CPW lines varied from 0.026 to 0.24 dB/mm over 3–170 GHz. For the microstrip lines, the average measured insertion loss over the same frequency range was extracted to be between 0.019 and 0.293 dB/mm. Furthermore, the parasitic inductance and resistance of a single-grounded TAV are extracted to be 24.41 pH and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.987~\Omega $ </tex-math></inline-formula> , respectively, at 50 GHz, and the insertion loss per a GSG-TAV extracted from CPW-TAV daisy chain measurements is found to be 0.056 dB at 50 GHz as well. In addition to an excellent performance of ARC-based interconnects, the TAV in ARC is shown to have lower transmission loss up to 50 GHz, while exhibiting low parasitics.

Flexible Copper Metal Circuits via Desktop Laser Printed Masks

AbstractA novel process is demonstrated that produces patterns of electrically conductive copper on a flexible polyimide film substrate using standard desktop laser printed toner and near room temperature aqueous chemistry. The laser toner acts as a mask to selectively block the ion exchange self‐metallization (IESM) reduction reaction that forms nanoscale silver or palladium coatings at the polyimide surface. The silver or palladium IESM coating is then used as a catalyst for electroless deposition of copper. Under appropriate conditions, the copper is deposited selectively on top of the catalyst layer. The resulting copper layer has a measured sheet resistance as low as 0.3 Ohms/sq. Electrical isolation is measured between copper traces spaced as close as 300 microns, and high conductivity is measured along traces with widths as low as 200 microns. The minimum pattern size appears to be limited primarily by the resolution of the laser toner pattern, as the IESM metal layer is observed to follow the contours of individual toner particles. The process avoids the use of high temperature, vacuum, and organic solvents and is thus suitable for very low cost prototyping or distributed manufacturing of simple electronic devices.

Localised aqueous corrosion of electroless nickel immersion gold-coated copper

ABSTRACT Electroless nickel (Ni) immersion gold (Au), commonly referred to by the acronym ENIG, is the most common protective coating applied on the exposed copper (Cu) traces of printed circuit boards (PCBs). In this work, we elucidate the local corrosion mechanism of the ENIG-Cu system by applying microscopic, surface analysis and electrochemical techniques with high spatial resolution to provide a comprehensive understanding of the complex local corrosion mechanism of the ENIG-Cu system. The corrosion initiation is highly localised and associated with pores or micro-defects in the Au layer. The corrosion initiates by the dissolution of the underlying Ni layer, being less noble than Au. The dissolution propagates in lateral and perpendicular directions relative to the surface in an elliptical fashion. With time, the direction of corrosion propagation changes to a predominantly lateral attack of the Ni layer. The corrosion process is governed by the cathode/anode ratio of the Au/Ni galvanic couple.

DFT Study of Some Copper Complexes and Their Detection Limit

A theoretical investigation was probed to shed light on the correlation between low detection limit (LOD) in AdSV technique and metal trace complexes stability energy. The study was conducted by means of DFT calculations of copper traces complexation by using three different organic molecules as chelating agents, such as: morin, red pyrogallol and thymolphtalexone. The quantum chemistry calculations were carried out at the B3LYP/6-31G(d) level implemented in Gaussian 09 program package. The results of the electrophilicity index ω indicate that all the studied molecules have a tendency to exchange electron with copper. The negative values of free energy G and enthalpy H show that the complexation reactions are spontaneous in nature and exothermic. According to DFT calculations, copper-red pyrogallol complex with better detection limit (0.07 ng•mL-1) has the lowest total energy (-5100.213 a.u.). Thus, there is a very strong relationship between the total energy of the three complexes and their detection limits in AdSV technique. Hence, the more stable complex has the better detection limit value.

Next-Generation High-Density PCB Development by Fan-Out RDL Technology

High-density interconnect (HDI) printed circuit boards (PCBs) are in high demand for smartphones, particularly those with fifth generation (5G) functionality, due to their smaller form factors, higher interconnection densities, and improved integrative ability. Various advanced PCB technologies are available, including HDI PCBs and substrate-like PCBs (SLPs). However, even for substrate-like PCBs, the line width (L) and spacing (S) of the copper traces are limited to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$25~\mu \text{m} / 25~\mu \text{m}$ </tex-math></inline-formula> , and fine-line development also faces yield and cost challenges. Accordingly, the present study utilizes an redistribution layer (RDL) first fabrication process to develop a fine line width/spacing ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10~\mu \text{m} / 10~\mu \text{m}$ </tex-math></inline-formula> ) Fan-out interposer (FOI) on PCB architecture with a higher I/O (Input/Output) density, greater yield, and lower cost. A three-dimensional (3D) ANSYS finite element (FE) model combined with volume fractions approach applied to equivalent thermomechanical properties of the multilayer RDL is introduced. The validity of the simulation model is confirmed by comparing the numerical results for the out-of-plane deformation of the top surface of the FOI with the experimental observations. Then, the effects of five design parameters on the warpage and solder joint stress performance of the FOI-PCB architecture are identified through parametric analysis. Finally, a second-order response surface methodology (RSM) model and Box-Wilson central composite design (CCD) method are employed to examine the interactive effects of the structural design factors of the FOI-PCB architecture on the FOI warpage under typical manufacturing thermal loading conditions. It is shown that a smaller overall size of the FOI is beneficial in reducing the warpage by minimizing the coefficient of temperature expansion (CTE) mismatch between the interposer and the PCB.

Scalable Manufacturing of Liquid Metal Circuits

AbstractLiquid‐metal (LM)‐based soft and stretchable electronics (SSEs) provide unique advantages for wearable computing, soft robotics, and implantable devices applications involving physical interaction with biological tissues and delicate objects. However, the lack of scalable manufacturing techniques prevents their mainstream adoption and commercialization. This paper introduces a scalable and reproducible manufacturing technique for wafer‐level fabrication of LM‐based SSEs, including LM‐only devices and hybrid circuits with LM and solid‐state microelectronics. The approach combines selective metal‐alloy wetting (SMAW) and controlled dip‐coating of eutectic gallium‐indium (EGaIn). The alloying of EGaIn and metal enables depositing EGaIn selectively onto the circuit layout defined by lithographically patterned copper traces on elastomer‐coated wafers. An automated, wafer‐level dip‐coating (DC) approach is developed to enable controllable and reproducible deposition of EGaIn. Wafer‐level simultaneous fabrication of many LM capacitors is demonstrated, and their geometric and electrical reproducibility is evaluated. The results indicate that the SMAW‐DC process can fabricate LM circuits reproducibly and rapidly. Hybrid SSEs are demonstrated by fabricating multiple wearable patches of ultra‐high frequency circuits with an LM dipole antenna, an LM strain gauge, and a solid‐state temperature sensor. Importantly, the presented technique can be integrated into the standard microfabrication flow for microelectronics, ensuring a high level of scalability.

Experience of using new generation additives in feeding of cows under the conditions of the Northern Trans-Urals

Highly productive cows react to insufficient and poor-quality feeding, which causes a decrease in productivity. Therefore, rations should be balanced for all the main nutrients and biologically active substances using highly effective special additives. The deficiency of trace elements and vitamins can be eliminated by introducing them with feed or boluses injected into the rumen. The purpose of the research was to study the effect of the feed additive of the prolonging action of Megabrik Prepavel and the feeding of zinc and copper trace elements in the form of Bioplex in the rations of cows during the increasing the milk yield period. The experimental part of the work on the study of feed additives of a new generation was carried out on cows of Black-and-White breed during the dry period and increasing the milk yield period on the basis of AO pedigree farm “Uchkhoz of the State Agrarian University of Northern Trans-Urals” in the winter-stall period. The influence of the new generation of feed additives in the form of Bioplex and prolonging boluses on milk productivity and physiological state of highly productive cows has been studied. The enrichment of the body with vitamins and minerals during the dry period and increasing the milk yield period has increased the dairy productivity of cows. When receiving Megabrik Prepavel boluses for completed lactation, an average of 6476,2 kg of milk with a fat content of 3,78 % and protein of 3,19 % was obtained from cows of the experimental group. Enrichment of the body with minerals and vitamins during the dry period allowed to increase milk productivity by 7,7 % and improve the quality of milk in fat by 0,04 abs.% and protein by 0,10 abs.%. In the experiment with the use of Bioplex in the ration milk yields have increased by 13,7 %. Milk fat yield was significantly higher by 16,56 kg or 19,28 % (P &lt; 0,01), and milk protein by 10,46 kg or 15,86 % (P &lt; 0,01). Input of additives normalizes metabolic processes in cows.