産業分野における表面分析のケーススタディ エレクトロニクス産業における表面分析

Summary form only given. Atmospheric pressure plasma treatment is a key process for surface preparation prior to adhesive bonding of plastics and composites for use in the aerospace, automotive, medical device, and electronics industries. A review is presented on methods for surface preparation of polymers and composites using low-temperature, atmospheric pressure radio frequency helium and oxygen plasmas. This is a promising technique for replacing traditional methods of surface preparation such as peel ply and abrasion. The plasma source generates an afterglow containing ∼1×1017 cm−3 oxygen atoms, ∼1×1017 cm−3 metastable oxygen molecules (1Δ g ), and ∼4×1014 cm−3 ozone molecules. With sufficient exposure to the afterglow, polymer and composite surfaces are fully activated such that when bonded and cured with epoxy adhesives, they undergo 100% cohesive failure. Depending on the material, lap shear strength and delamination resistance can be increased over 50% from that activated by solvent wiping or abrasion. Surface analysis by water contact angle and AFM indicates that there is no correlation between bond strength and surface energy or surface roughness. Instead, bond strength correlates with the fraction of the polymer surface sites that are oxidized and converted into carboxylic acid groups, as determined by x-ray photoemission and infrared spectroscopy. Polymers with aromatic groups in the backbone are especially suitable for activation with the atmospheric pressure plasma. The activation mechanism, surface characterization results, and bonding strength improvement are discussed in detail.

With the rapid advances of the electronics industry, a large amount of acidic etching waste solutions (AEWS) for etching Printed Circuit Board (PCB) are generated, which require complete remediation and sustainable recycling to avoid environmental pollution and wasting of resources. Herein, the novel purification technology for the acidic copper-containing etching waste solution was exploited via integrated alkali gradient pH control (3.0, 3.2, and 3.5). At pH 3.0, the system demonstrated selective metal removal with 94.02% efficiency for Fe and 82.60% for Mn. Elevating the pH to 3.2 enabled effective elimination of Zn (59.32%), Cr (59.46%), and Al (33.24%), while maintaining minimal copper loss (8.16%). Further pH adjustment to 3.5 achieved enhanced removal efficiencies of 97.86% (Fe), 91.30% (Mn), 59.38% (Zn), 62.10% (Cr), 21.66% (Ca), 34.05% (Al), and 26.66% (Co), with copper retention remaining high at 70.83% (29.17% loss). Furthermore, using the purified AEWS (pH 3.2) as precursor, high-purity nano-CuO was successfully synthesized through a Cu2(OH)3Cl conversion-calcination process, exhibiting 99.20% CuO purity with 0.0012% chlorine content and <0.1% metallic impurities. The development and application of the purification technology for AEWS containing copper, along with the production methodology for high-purity CuO, were significant to the fields of electronic information industry, environmental engineering, green industry and sustainable development of the ecological environment.

Mathematical modeling of signal transfer process into optical system of a linear displacement encoder

Continual advances in the electronics industry and other high heat-flux fields have led to a need for increased heat transfer efficiency. Spray cooling is one of many methods for removing heat from surfaces. Experimental testing conducted at West Virginia University was sponsored by the Air Force Office of Scientific Research in collaboration with the Air Force Research Laboratory to test the effectiveness of using inductive spray charging to enhance the heat transfer rate. Modifications made to the experimental test rig built by Hunnell (2005) enabled the study of electro-hydro-dynamics.;Experimental testing using working fluids, FC-72 and HFE-7000, was conducted. Electrodes were designed to inductively charge spray droplets (Law, 1978). Research was performed by studying the thermophysics for different spray flow rates ranging from 6 to 10 GPH with a stepwise applied heat load ranging from 0 to 120 W, for an applied electrode voltage between 0 to 6 kV.

Magnesium is demanded increasing in aerospace, electronics industry and medical field requires the surface treatment method. That allows increasing the corrosion resistance in order to put to practical use as products. The spark anodized treatment method in this study used was anodized depending on the various times to 1-4 minutes with a current density of 300 mA/cm2 in the constant-current mode that duty cycle is 50% and frequency is 125 Hz by a bipolar pulse power. And the characteristics of the film were evaluated. This treatment method is to obtain the uniform film by reducing the applied voltage on the surface by adding 0.1 M Sodium silicate (Na2SiO3) in the mixed solution of 2.0 M Sodium hydroxide (NaOH) and 0.1M Sodium phosphate (Na3PO4). It aims to express brown or dark brown color by adding Potassium permanganate, and to improve the corrosion resistance. After anodization treatment, the surface characteristics were analyzed using SEM, XRD and illuminance meter, and Vickers hardness was measured. In order to evaluate of corrosion resistance, the corrosion potential and corrosion current were measured by potentiodynamic method in 3.5 wt. % NaCl electrolyte. The critical voltage required to generate the oxidized layer could be lower depending on the addition of (Na2SiO3) and (KMnO4). The size of a pore was reduced depending on the processing time, and the thickness of the film was grown in proportion to it. As the result of XRD, a new peak of Mg0.9Mn0.1O was formed, and the peak of parent metal was reduced by the increase of the oxide. By the potentiodynamic polarization behavior, the value of corrosion potential was increased and the corrosion current density was decreased and the corrosion resistance was improved.

This studied aimed at improving the mechanical properties for a new biopolymer feedstock using laser-sintering technology, especially when its laser-sintered parts are intended to be applied in the industrial and medical fields. Process parameter optimization and thermal post-processing are two approaches proposed in this work to improve the mechanical properties of laser-sintered 10 wt % cellulose-polylactic acid (10%-CPLA) parts. Laser-sintering experiments using 23 full factorial design method were conducted to assess the effects of process parameters on parts’ mechanical properties. A simulation of laser-energy distribution was carried out using Matlab to evaluate the experimental results. The characterization of mechanical properties, crystallinity, microstructure, and porosity of laser-sintered 10%-CPLA parts after thermal post-processing of different annealing temperatures was performed to analyze the influence of thermal post-processing on part properties. Image analysis of fracture surfaces was used to obtain the porosity of laser-sintered 10%-CPLA parts. Results showed that the optimized process parameters for mechanical properties of laser-sintered 10%-CPLA parts were laser power 27 W, scan speed 1600 mm/s, and scan spacing 0.1 mm. Thermal post-processing at 110 °C produced best properties for laser-sintered 10%-CPLA parts.

The Effect of Innovation Activities on Innovation Performance according to the size of SMEs in the Field of Electronics and Communication Industry

Computer numerical simulations for accelerated design of rare earth permanent magnet motors in renewable energy applications: A review

This study aimed at evaluating the level of conformity of the learning activities and any factors that causing mismatch of the learning activities of vocational subjects in Vocational High School with Electronics Industrial Engineering experties program from SKKNI Number 631 Year 2016 with industrial automation field. This study was conducted in SMK Muhammadiyah Prambanan, SMK N 2 Pengasih, SMK N 4 Semarang, and SMK N 7 Semarang with CIPP model and quantitative descriptive analysis technique. The result showed that the level of conformity of the learning activities from the aspects of context, input, process, and product with teacher and student as respondent was categorized appropriate to very appropriate. Factors that causing mismatch of the learning activities with that SKKNI is the orientation of syllabus and RPP preparation, the facilities and infrastructure that supprot the learning activities, and the teacher’s ability on supporting the competence experties in industrial automation field.

Copper-based alloys are widely used in the consumer electronics industry for components such as connector contacts, shielding gaskets, and terminals. Nickel silver is a general term for alloys that contain copper, nickel, and zinc. Nickel silver first became popular as a base metal for silver-plated cutlery and other silverware, notably electro-plated nickel silver, jewelery and coins. In this article, the electrochemical stability of Cu–10Ni–10Zn alloy was compared with that of pure copper and two of copper ternary alloys, namely Cu–10Al–10Zn and Cu–10Al–10Ni in synthetic sweat solution, Hank’s solution and in Ringer physiological solution. Corrosion behavior of the different electrodes was investigated using cyclic voltammetry, potentiodynamic polarization, and impedance spectroscopy techniques. The CVs showed peaks concerning the redox reactions for copper. These peaks were assigned to the formation and reduction of copper species. Furthermore, they showed that the copper oxidation was suppressed to a large extent by the presence of Ni and zinc in the alloy composition than the presence of Al and Zn or the presence of Al and Ni elements. Also, the results showed that the Cu–10Ni–10Zn alloy exhibited good corrosion resistance due to the formation of a protective passive film. The electrochemical impedance spectroscopy results indicated that either a duplex film with an inner barrier layer and an outer porous layer or a single passive layer was formed on the surface. The formation of such passive film was discussed, and the different alloy surfaces examined by scanning electron microscopy and subjected to EDAX analysis. The surface analysis has shown the participation of the different alloying elements in the passive film according to the alloy constituents. Addition of Ni decreases the rate of corrosion of the Cu, and the Cu–10Ni–10Zn was found to be the most corrosion-resistant alloy.

X-ray Photoemission Spectroscopy (XPS) is a surface-sensitive analytical technique commonly used in the field of materials science at the nanoscale level. Historically applied to the industrial field, it is also successfully used in the investigation of Cultural Heritage, both for diagnostics and for conservation purposes. The nature and the state of conservation of artefacts can be assessed by XPS surface analysis, evidencing the presence of efflorescence, patinas, degradation/corrosion products, coatings and protective layers applied in restoration treatments. The feasibility of probing the surface reactivity in the nanometric range and understanding the chemical processes, occurring in different aggressive environments, makes XPS a very powerful tool also in the field of Conservation of Cultural Heritage. This analytical technique can be very fruitfully employed for the validation of new eco-compatible conservation products (e.g. corrosion inhibitors for metallic artworks) and for the choice of the suitable conservation and restoration protocols. In this work, some case-studies related to the application of XPS to the conservation of copper-based and iron-based alloys artefacts are reported. In particular, the focus is on the evaluation of the conservation state and the identification of degradation phenomena of archaeological bronzes and on the assessment of naturally-derived corrosion inhibitors for a sustainable conservation of iron-based artworks.

The separation and recycling of effective resources in Fischer-Tropsch wax residue (FTWR) are urgent because of the environmental hazards and energy waste they bring. In this study, organic solvents are used to separate recyclable resources from FTWR efficiently, achieving the goals of “Energy Recycle” and “Fisher-Tropsch Wax Residue Treatment”. The response surface methodology (RSM) response surface analysis model accurately evaluates the relationship among temperature, residence time, liquid–solid ratio, and desorption rate and obtains the best process parameters. The results show that the product yield can reach 82.28% under the conditions of 80 °C, 4 h, and the liquid–solid ratio of 24.4 mL/g. Through the kinetic analysis of the desorption process of FTWR, the results show that the desorption process conforms to the pseudo second-order kinetic model and the internal diffusion model. The thermodynamic function results showed that there were not only van der Waals forces in the desorption process, but other strong interaction forces such as hydrogen bonds. In addition, Langmuir, Freundlich, and BET equations are used to describe the desorption equilibrium. Scanning electron microscopy (SEM) were used to analyze the pore structure of FTWR during desorption. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Gas chromatography-mass spectrometer (GC-MS) analysis confirmed that the desorption product’s main component was hydrocarbons (50.38 wt%). Furthermore, naphthenic (22.95 wt%), primary alcohol (11.62 wt%), esters (8.7 wt%), and aromatic hydrocarbons (6.35 wt%) compounds were found and can be further purified and applied to other industrial fields. This study shows that using petroleum ether to separate and recover clean resources from Fischer-Tropsch wax residue is feasible and efficient and has potential industrial application prospects.

This paper addresses the fault detection and isolation (FDI) problem for robotic assembly of electrical connectors in the framework of set-membership. Both the fault-free and faulty cases of assembly are modeled by different switched linear models with known switching sequences, bounded parameters, and external disturbances. The locations of switching points of each model are assumed to be inside some areas but the accurate positions are not clear. Given current input/output data, the feasible parameter set of fault-free switched linear model is obtained by sequentially calculating an optimal ellipsoid. If the pair of data is not consistent with any possible submodel, a fault is then detected. The isolation of fault is realized by checking the consistency between the data sequence and each possible fault model one by one. The robustness of the proposed FDI algorithms is proved. The effectiveness of these algorithms is verified by the robotic assembly experiments of mating electrical connectors. Note to Practitioners —In modern robotic assembly tasks, the industrial robots often need to manipulate tiny objects with complex structure. Electrical connectors are a typical kind of these objects and widely used in many industrial fields. To avoid damaging the fragile connectors and accelerate the assembly process, it is required to promptly detect and isolate the certain assembly fault in real time so that the robot can immediately implement an error recovery procedure according to the identified fault. The proposed set-membership-based fault detection and isolation (FDI) methodology satisfies both the timing and fault-isolation requirements for this kind of robotic assembly task. In terms of the set-membership theory, no false alarm will occur if there are sufficient training data for the proposed method. In addition, it turns out that the proposed method can signal an alarm faster than conventional residual-based FDI method from plentiful experiments. Although only the robotic assembly of electrical connectors is investigated, our FDI method can also be applied in the assembly task of other small and complex parts. This is especially useful for increasing the productivity and promoting the automation level of electronic industries.

It is essential to develop the dielectric energy storage capacitor for the modern electrical and electronic equipment. Here, the all-organic sandwich-structured composite with superior breakdown strength and delayed saturation polarization is presented. Furthermore, the energy storage characteristics of the composite are enhanced by the poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) fiber and the redistribution of local electric field. The dielectric permittivity of composite increases to ∼16, and the discharged energy density is high to ∼8.7 J/cm3 at 360 kV/mm, and the breakdown strength is up to ∼408 kV/mm. The excellent performance of the composite broadens the application in the field of power electronics industry.

Composite materials are widely used in modern production processes. Polymer composite materials, especially from the ABS group with different physical and mechanical properties have great potential in the field of electronic industry. To date, additive technologies are actively used, which requires a new approach to modeling the physical properties of various polymers, passing into a new state at the time of homogenization. For products made of polymeric materials with the use of additive technologies is characterized by the dependence of the final mechanical properties not only on the design, but also on the technological modes of manufacture, as in the manufacturing process is formed by a complex spatial structure of the layers, which leads to heterogeneity of the properties of different parts of the product. The structure of polymers is related to the properties of the final product and the level of quality.