Production Process Of Components Research Articles

Adhesion enhancement by a dielectric barrier discharge of PDMS used for flexible and stretchable electronics

Currently, there is a strong tendency to replace rigid electronic assemblies by mechanically flexible and stretchable equivalents. This emerging technology can be applied for biomedical electronics, such as implantable devices and electronics on skin. In the first step of the production process of stretchable electronics, electronic interconnections and components are encapsulated into a thin layer of polydimethylsiloxane (PDMS). Afterwards, the electronic structures are completely embedded by placing another PDMS layer on top. It is very important that the metals inside the electronic circuit do not leak out in order to obtain a highly biocompatible system. Therefore, an excellent adhesion between the 2 PDMS layers is of great importance. However, PDMS has a very low surface energy, resulting in poor adhesion properties. Therefore, in this paper, PDMS films are plasma treated with a dielectric barrier discharge (DBD) operating in air at medium pressure (5.0 kPa). Contact angle and XPS measurements reveal that plasma treatment increases the hydrophilicity of the PDMS films due to the incorporation of silanol groups at the expense of methyl groups. T-peel tests show that plasma treatment rapidly imparts adhesion enhancement, but only when both PDMS layers are plasma treated. Results also reveal that it is very important to bond the plasma-treated PDMS films immediately after treatment. In this case, an excellent adhesion is maintained several days after treatment. The ageing behaviour of the plasma-treated PDMS films is also studied in detail: contact angle measurements show that the contact angle increases during storage in air and angle-resolved XPS reveals that this hydrophobic recovery is due to the migration of low molar mass PDMS species to the surface.

Close co-operation the key for PM component success

New applications for PM have resulted in substantial market growth during the last 30 years. The clue to this success lies in the use of new powders and component production processes. To reduce development time and increase the likelihood of commercial success it is essential for the whole chain from powder supplier to component manufacturers and end users to work in close co-operation…

Exterior components based on renewable resources produced with SMC technology—Considering a bus component as example

The importance of renewable resources in technical applications has increased. Within the framework of the studies, a bus body component based on natural fibres and PTP ®, a vegetable based thermoset resin, is produced with the sheet-moulding-compound technology (SMC). Hitherto, the conventional component was produced of glass fibre reinforced polyester resin. The mid-term results of the studies show that it is possible to optimise the production of this textile semi-finished part by selecting qualified hemp fibres and developing a technically matured PTP ®-SMC variant in such a way that the component production process based on the semi-finished parts need not be changed. All in all, it was possible to produce a homogeneous body part with the hemp/PTP ®-prepreg due to the flow ability that was achieved for the natural fibres. The technical feasibility of producing an SMC-component based on renewable resources was demonstrated. The properties of the component, e.g. tensile strength, burning behaviour and water absorption, are shown and compared to the results of the series component. An assessment of the component from the end-user perspective is presented. According to the End-of-Life Vehicles Regulation, there is no advantage in components based on renewable resources over components based on petrochemical resources. However, the application of renewable resources has advantages in terms of recycling technologies, which are accepted for SMC and which will become economically more important in the future. In comparison with the polyester system, the life-cycle assessment of the polymer material PTP ® shows lower values in nearly all impact categories.

Micro assembly injection moulding

Injection moulding is established as one of the most common manufacturing processes of thermoplastics due to its high degree of automation and the short cycle times. Micro injection moulding is a rapidly growing technology that allows for the efficient production of very complex micro parts in high series. The “Market Analysis for Microsystems II 2002–2005” of the Nexus Task Force anticipates a yearly growth in the field of micro system technology of about 20% (Wechsung et al. 2002). This study identifies in addition to the continuous miniaturization the growing use of polymers in micro systems (Schneider et al. 2001). No other material group offers this wide range of material properties and permits to choose processing parameters and application properties according to necessities (Gachter 2000). While the production processes of micro technical components are mainly controllable, the assembly of these components to hybrid micro systems is a bottleneck to the industrial large scale production. The assembly itself represents a large fraction of the added product value and gains in importance with growing complexity and miniaturization of the systems.

MEMS integrated submount alignment for optoelectronics

One of the most expensive and time-consuming production processes for single-mode fiber-optic components is the alignment of the photonic chip or waveguide to the fiber. The alignment equipment is capital intensive and usually requires trained technicians to achieve desired results. Current technology requires active alignment since tolerances are only /spl sim/0.2/spl mu/m or less for a typical laser diode. This is accomplished using piezoelectric actuated stages and active optical feedback. Joining technologies such as soldering, epoxy bonding, or laser welding may contribute significant postbond shift, and final coupling efficiencies are often less than 80%. This paper presents a method of adaptive optical alignment to freeze in place directly on an optical submount using a microelectromechanical system (MEMS) shape memory alloy (SMA) actuation technology. Postbond shift is eliminated since the phase change is the alignment actuation. This technology is not limited to optical alignment but can be applied to a variety of MEMS actuations, including nano-actuation and nano-alignment for biomedical applications. Experimental proof-of-concept results are discussed, and a simple analytical model is proposed to predict the stress strain behavior of the optical submount. Optical coupling efficiencies and alignment times are compared with traditional processes. The feasibility of this technique in high-volume production is discussed.

Fabrication of large-sized complex-shaped components from quartz ceramics: Research and practical aspects. Part 1. Statistical analysis of the stability of the technological process

Results of a statistical analysis of the production process of large-sized components from quartz ceramics are presented. The technologies examined are characterized by a long-term stability which makes it possible to reliably control the production process and reach the required level of physicomechanical properties.

Information technologies applied to the manufacturing of complex mechanical parts

The aim of the present paper is to report the use of information technologies to control and assure the quality of complex mechanical parts, in this case crankshafts. Three different automated cells are used for inspection purposes using Non Destructive Techniques (NDT): Automated Visual Inspection (AVI), a surface Roughness Measurement System (RMS) and a Dimensional Control System (DCS). Distributed control architecture allows integral quality assessment of the production process of valuable machined components. A suitable software subsystem has been developed for this architecture: a Quality Assessment Subsystem (QUAL), a Tracking Subsystem (TS) and an intelligent production Process Assessment Subsystem (PAS). A prototype has been successfully installed and is under evaluation in a production line belonging to Renault Industrial Vehicles (Spain).

W-Cu의 마이크로 금속분말사출성형

The production of micro components is one of the leading technologies in the fields of information and communiation, medical and biotechnology, and micro sensor and micro actuator system. Microfabrication (micromachining) techniques such as X-ray lithography, electroforming, micromolding and excimer laser ablation are used for the production of micro components out of silicon, polymer and a limited number of pure metals or binary alloys. However, since the first development of microfabrication technologies there have been demands for the cost-effective replication in large scale series as well as the extended range of available material. One such promising process is micro powder injection molding (PIM), which inherits the advantages of the conventional PIM technology, such as low production cost, shape complexity, applicability to many materials, applicability to many materials, and good tolerance. This paper reports on a fundamental investigation of the application of W-Cu powder to micro metal injection molding (MIM), especially in view of achieving a good filling and a safe removal of a micro mold conducted in the experiment. It is absolutely legitimate and meaningful, at the present state of the technique, to continue developing the micro MIM towards production processes for micro components.

Interface and ionic interdiffusion in cofired ferroelectric/ferrite multilayer composites

Recently, the surface mount technology (SMT) has been rapidly developed for miniaturization of electric devices such as multilayer ceramic capacitor (MLCC) and multilayer chip inductor (MLCI). The trend of electronics has been for an increasingly compact design. Some characterizations of cofired devices such as ceramic-filled glass electronic package, and varistorcapacitor cofired multilayer device have been reported [1, 2]. Multilayer chip LC filter, which is combined with several capacitors and inductors by the production process of multilayer chip components, is a type of advanced surface mount devices (SMD). Lead based relaxor ferroelectrics, such as Pb(Mg1/3Nb2/3)O3, Pb(Ni1/3Nb2/3)O3 and Pb(Zn1/3Nb2/3)O3, are being widely used as MLCC due to their high dielectric constant and low sintering temperature [3–5]. And NiCuZn ferrite, which has excellent magnetic permeability and can be densified at low temperature, is an important material using for producing low temperature sintered MLCI [6–8]. They are promising materials for the multilayer chip LC filters. The key issue of manufacturing the multilayer chip LC filters is cofiring the capacitor and inductors together at low temperature. The interfacial interactions such as chemical reaction, ionic interdiffusion, are important for the production of devices. In the present study, the multilayer components were prepared by cofiring Pb(Ni1/3Nb2/3)O3-PbTiO3 (abbreviated as PNNT) ferroelectrics and NiCuZn ferrite. The cofiring interface and ionic interdiffusion between constituents were investigated. According to the diffusioncouple model, the interfacial diffusion coefficient for Pb2+, Nb5+, Ni2+, and Fe3+ had been estimated. The specimens were prepared by the conventional oxide-mixing technique. 99% pure reagent-grade PbO, NiO, Nb2O5, TiO2, Fe2O3, CuO, and ZnO oxides were weighed in the appropriate proportions and used as starting materials. Fe2O3, NiO, CuO and ZnO powders, according to the composition (Ni0.8Cu0.1Zn0.1)Fe2O4, were calcined at 720 ◦C for 4 h to fabricate NiCuZn ferrite. The dielectric material, according to the composition 0.8 Pb(Ni1/3Nb2/3)O3-0.2PbTiO3 with little amount of CuO and ZnO, were calcined at 800 ◦C for 4 h. The calcined mixtures were ground by ball milling for 12 h to a proper surface area. The ground powders were dried and added to PVA for the disk bodies. Firstly, ferroelectic and ferrite disks were separately prepared and sintered at 850–950 ◦C for 2 h, in order to measure characteristics such as phase structure and sintered densities. Secondly, the mixed calcined powders of ferroelectric and ferrite were laminated into a mold and compressed into a plate with the diameter of 12 mm, which was sintered at 950 ◦C for 2 h. The sintered densities were measured by the Archimedes method. The phase structure for the specimens were identified using X-ray diffractometer (XRD). For lead-based ferroelectrics, perovskite phase and pyrochlore phase always coexist. The relative amounts of perovskite and pyrochlore phases were determined by measuring the major X-ray peak intensities for perovskite and pyrochlore phases, i.e. (110) and (222), respectively. The percentage of perovskite phase was calculated by the following equation [9]:

Mid-temperature Isomerization of Light Naphtha Cuts. The Isomalk Process: Experience in Industrial Introduction

The modern requirements for the environmental properties of automotive gasolines make it necessary to expand production of nonaromatic high-octane components. Of the production processes for such components, the process of isomerization of light naphtha cuts is distinguished by low cost, high (96-99 wt. %) yield of target product, and simplicity of the technology.

컴퓨터의 전과정평가

The life cycle assessment on a computer is performed in order to identify the environmental impacts during the life cycle of a computer and to establish the database to develop environmentally friendly computers. This article contains simplified results from the life cycle assessment on a computer. A desktop PC set that consists of a PC mainframe (including Pentium II processor) and a monitor (having 17-inch screen) is chosen as the functional unit for this study. Site-specific data are collected for the component production processes and the assembly processes. Material production and energy related data are derived from literature since it is too difficult to collect site-specific data for those. The impact categories considered in this study are abiotic resource depletion, global warming, stratospheric ozone depletion, photochemical oxidant creation, acidification, eutrophication, human toxicity and eco-toxicity. The characterization results are integrated into single value through normalization and weighting. The use phase in the life cycle of a desktop PC is the most major contribution as 54.8% of total impact assessment value. And other major contributing components in production are monitor, mother board, SMPS, modem, HDD and so on. The results from the life cycle assessment on a computer are used to establish the strategy for improving environmental performance of computer and to provide environmental information of the product to customers.

Optimal machine settings of imperfect component production processes for assembly operations

The present work is motivated by a problem occurring in a fabrication and assembly operation of fuel injectors for automobile engines. The production processes of the individual components to be assembled are imperfect. For a specific machine setting, which can be preset by an operator, the dimensions of the outputs of a component production process are variable. Components can be assembled only if their dimensions are within some given specification limits of each other. The problem of determining the optimal machine settings of two component production processes to maximize the expected outputs of the assembly operations is considered. The properties of the optimal solution are studied, and some numerical examples are presented. >

Inner-product optical neural processing and supervised learning

Increasing demands for reliable production processes of micro-scale components in large quantities has promoted the research on micro cold forming processes. The need to accelerate product design by the use of simulation has revealed limitations of the classical finite element method (FEM) in the sub-millimeter domain where the local behavior may be dominated by one or a few grains only. As a consequence, average material characteristic values obtained from macroscopic specimens are no longer sufficient to describe the local work-piece behavior. Instead, an uncertainty of the material parameters is encountered, which can be characterized mathematically by probability distributions.The research activities presented here focus on the feasibility of FEM simulations based on distributed material parameters. In order to reduce the computational load, pre-calculation of a sufficient number of load cases in representative volume elements (RVE) for usage in a material data base is proposed. Work-piece simulations are then performed as a multi-scale approach with different levels of interactions between adjacent RVEs.Material characterizations of DC01 sheets and their application to numerical simulation of bulge-tests are presented.