bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multilayer process for the connection of fine‐pitch‐devices on molded interconnect devices (MIDs)
Authors: Leneke Thomas , Hirsch Soeren , Schmidt Bertram 
Published: May 2009

PurposeThe purpose of this paper is to present a new multilayer process for three‐dimensional molded interconnect devices (3D‐MIDs) that allows the assembly of modern area array packaged semiconductors.Design/methodology/approachA new 3D‐MID multilayer process based on local overmolding is developed. To investigate this new process, a 3D demonstrator is designed, simulated and fabricated. Various technologies such as injection molding, maskless laser assisted electroless metallization, overmolding and laser via drilling are used.FindingsUsing the new 3D‐MID multilayer process a 3D demonstrator with three metallization layers is fabricated. Injection molding simulation is utilized to ensure a feasible demonstrator design. It is shown that a surface laser treatment improves layer‐to‐layer adhesion during the process. Shear and pull tests prove the adhesion promotion. The 3D fine‐pitch‐metallization is done down to 60 μm track width. Via resistance is measured by four terminal sensing in agreement with previous results. Design rules for process compatible vias are introduced. The fabricated demonstrator is suitable for flip‐chip‐based area array packaged semiconductors.Research limitations/implicationsA proof of concept is given by the fabricated demonstrator. Further, work should include reliability tests of the multilayer structures and improvement of individual process steps.Originality/valueThe paper describes a new multilayer process for 3D‐MIDs. It overcomes existing restrictions regarding the electrical routing on 3D‐MID surfaces. The compatibility of area array packaged semiconductors with a high‐inputs/outputs count and the 3D‐MID technology is improved.
Reflow ageing influences and wettability effects of immersion tin final finishes with lead‐free solder
Authors: Hetschel Thomas , Wolter Klaus‐Jürgen , Phillipp Fritz 
Published: May 2009

PurposeThe purpose of this paper is to investigate the oxidation behaviour of an immersion tin final finish after multiple reflow ageing under air and nitrogen atmospheres and to study their influence on the wetting behaviour with lead‐free solder. To design a model that describes the degradation of wetting behaviour after reflow‐cycling of the immersion tin final finish.Design/methodology/approachA special printed circuit boards (PCB) demonstrator was created to investigate the immersion tin final finish with surface analysis methods and wetting tests. The PCB samples were aged by multiple reflow‐cycling under air and nitrogen atmospheres. The tin oxide formation behaviour of immersion tin was characterised using X‐ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM) and SERA analysis.FindingsThe native oxide layer of the investigated immersion tin final finishes was approximately 7 nm on average. The TEM and XPS investigations indicated an amorphous structure of SnO and SnO2. The solder spread test showed significantly different results for PCBs in “as received” condition compared to those after one and two times reflow ageing under a nitrogen solder atmosphere. The analysis methods revealed a slight increase in the tin oxide layer thickness and small areas with semi‐crystalline structure. Reflow ageing under an ambient solder atmosphere induced considerably thicker oxide layers, which could be observed by a yellow discoloration of the surface.Research limitations/implicationsMeasures to improve the wetting behaviour can be derived from the described model (i.e. use of higher tin layer thickness or protective films to reduce the tin oxidation).Originality/valueA functional model for the solderability process of lead‐free solder on immersion tin PCB final finishes was derived and verified. By this, interactions between the state of the final finish and the solder can be described and potential solderability failures can be predicted.
Putting the public in the public domain
Authors: Sheppard Tamara 
Published: May 2009

PurposeThe purpose of this paper is to attempt to highlight the imminent corrosion of the public domain brought about by the pervasive lack of recognition within the public at large regarding what the public domain is, what it stands for, and what it is meant to accomplish.Design/methodology/approachUtilizing the diverse theories of proponents of the public domain, this analysis proposes a re‐conceptualization of the public domain which acknowledges its significance to the creative process itself, and subsequently stresses the importance of public awareness and participation to its continuing survival.FindingsWhile remarking on the efficacy of a number of digitization ventures in the promotion of the public domain, it is concluded that mere awareness of the plight of the public domain is not enough. What the public domain desperately needs to subsist is the presence of an active citizenry that is dedicated to preserving its interests. Moreover, the public library is emphasized as the ideal vehicle with which to elucidate the public and secure their involvement in a campaign to safeguard an endangered public domain.Originality/valueThis paper expounds on the necessity of bringing the public and the public domain together so that both are empowered to dispel the restrictions that have arisen from an excessive copyright protectionist regime and so that both are enabled to defend themselves from any further encroachments on their ability to progress and mature within their own cultural bounds.
Does universal access mean equitable access?
Authors: Klimaszewski Cheryl , Nyce James M. 
Published: May 2009

PurposeThe purpose of this paper is to present the findings from a field study in Viscri, a village in Transylvania, Romania, to investigate the current state of information and communication technology (ICT) development in the village.Design/methodology/approachResearchers interviewed villagers in May 2007. Ethnographic methods were used to collect data and to assess villagers' information needs. The information landscape in Viscri is presented and analyzed in local and national contexts. The national policies shaping Romania's emerging information society are discussed and literature on the impact of ICT development at the community level is also reviewed.FindingsRomania's ICT policy goal of universal access needs to be better targeted. In Viscri, few adults showed interest in learning about or using computers. However, villagers understood that a good education that included computer education was necessary to assure better economic futures for their children. In light of the demographics, social conditions and cultural beliefs in Viscri, the most appropriate access point for ICT initiatives there should be programs aimed at school‐aged children.Research limitations/implicationsThe paper describes and discusses the information needs of one village. Further field investigation at the community level is necessary to discern the relevance of the findings to other villages both in Romania and elsewhere.Practical implicationsFurther research, especially in the most underserved communities, will help to identify ways in which the information society and related policies can be more equitably implemented in Romania. What is learned in Romania can have implications for ICT development policy elsewhere.Originality/valueThe paper assesses critically the rhetoric of universal access. If universal access is going to remain an ICT policy goal, more research is needed at the community level in order to ensure that policy emphasis on access for all actually translates into equitable, meaningful ICT access for underserved communities.
Professional education, development and training in a Web 2.0 environment
Authors: Broady‐Preston Judith 
Published: May 2009

PurposeThe purpose of this paper is to explore concepts of professional education, development and training within the context of a changing information landscapeDesign/methodology/approachThe paper analyses selected literature, including governmental and professional body reports, focusing particularly on the implications of these for the contemporary and future education, training and development of the information profession. Key issues addressed are the impact of the government skills agenda and the increasing use of competency based frameworks.FindingsEvidence suggests that the information profession is undergoing a period of profound change in relation to its qualifications base. The paper concludes that many of the previously enshrined shibboleths of professional education, training and development are undergoing a fundamental re‐examination. Barriers relating to qualification levels, to professional practice and to career development, are being circumvented or demolished. In a volatile climate of rapid change, continuing professional development (CPD) is necessary if professionals wish to keep abreast of new skills and knowledge.Originality/valueThe paper identifies and discusses the current drivers for change in relation to the skills, competencies, education, training, and development, for the information profession, including issues in relation to defining “professionalism”. As a contribution to contemporary debate on these issues, the paper should be of use to policy makers, practitioners, researchers and students.
Digital discovery: strategies and solutions
Authors: Kallenborn Reiner , Becker Carolin 
Published: May 2009

PurposeThe purpose of this paper is to provide an overview of the 29th IATUL Conference on “Digital discovery: strategies and solutions” held in Auckland, New Zealand in April 2008.Design/methodology/approachThe article gives an outline of the issues, content, keynote speakers, social networking and location of this conference.FindingsThe IATUL meeting presented a wide range of cutting‐edge topics defining the future roles of librarians in a globalised information society. Participants gained insights into the workings and visions of librarians around the globe, had the opportunity to share experiences and best practice and to find new inspiration and encouragement for their own daily work. The conference included areas such as policies for the information society, digitalization strategies, open access initiatives, e‐research developments, library support for e‐science, library customer orientation, Web 2.0 applications for libraries, learning experiences of the Net generation, information literacy as well as data and knowledge management.Originality/valueThe paper provides a conference report of value to library and information professionals, in particular to library directors and senior managers, regarding the development of a modern dynamic infrastructure for digital information and communication and the role of libraries therein.
Tough economic times for US libraries
Authors: Topper Elisa F. 
Published: May 2009

PurposeThe purpose of this paper is to explore the impact that the recession has had on US libraries.Design/methodology/approachThe paper is an overview of the literature.FindingsThe recession has had an impact not only on libraries but also related fields such as publishing.Originality/valueThe paper makes libraries aware that planning is essential in order to survive in the recession.
American Library Association Conference 2008
Authors: Ashcroft Linda 
Published: May 2009

PurposeThe purpose of this paper is to provide a flavour of the content of the American Library Association Annual Conference held in Anaheim in June 2008.Design/methodology/approachThis is an outline description of the issues, content, networking, speakers and participants of this conference.FindingsThis major conference covered many topical issues and themes, latest trends and research, and leading edge technology applicable to librarians and information professionals internationally. It facilitated many networking opportunities.Originality/valueThis paper is a conference report of value to librarians and information professionals as the variety of themes apply to the various aspects of library and information work.
Symmetrization of asymmetrical nonlinear three‐phase load supplied from non‐ideal sinusoidal voltage source
Authors: Dębowski Krzysztof , Pasko Marian 
Published: May 2009

PurposeThe purpose of this paper is to deal with the problem of symmetrization of asymmetrical three‐phase delta connected nonlinear load. In the model of the three‐phase sinusoidal voltage source have also been included inner impedances. The purpose is to obtain symmetrical line currents of the voltage source, to minimize RMS values of currents and to minimize higher harmonics generated by nonlinear loads.Design/methodology/approachThis symmetrization of the system is realized by means of a symmetrizing system, which is composed of LC one‐ports. In order to solve the problem the symmetrical component theory is applied. The structure of symmetrizing system is consisted of two components: parameters determined for the basic harmonic and the filter for elimination of the higher harmonics generated by nonlinear loads.FindingsAfter symmetrization line currents of the source will be symmetrical with lower RMS values than before symmetrization, and the source will generate the greater active power than beforehand.Research limitations/implicationsThis approach can be used for inertialess (non‐reactive) elements in systems, where currents are periodical.Practical implicationsThe results of symmetrization can be useful for high‐power systems where LC one‐ports can be used, e.g. for arc furnaces.Originality/valueApplication of presented methods makes possible to improve the working point of the system, i.e. voltage source can generate greater active power than before symmetrization and line currents can be symmetrical.
Broken rotor bar impact on sensorless control of induction machine
Authors: Kołodziejek Piotr , Bogalecka Elżbieta 
Published: May 2009

PurposeThe purpose of this paper is analysis of the sensorless control system of induction machine with broken rotor for diagnostic purposes. Increasing popularity of sensorless controlled variable speed drives requires research in area of reliability, range of stable operation, fault symptoms and application of diagnosis methods.Design/methodology/approachT transformation used for conversion of instantaneous rotor currents electrical circuit representation to space vector components is investigated to apply with closed‐loop modeling algorithm. Evaluation of the algorithm is based on analysis of asymmetry influence to the orthogonal and zero components of space vector representation. Multiscalar model of the machine and selected structures of state observers are used for sensorless control system synthesis. Proposed method of frequency characteristics calculation is used for state observers analysis in open‐loop operation.FindingsNew algorithm of applying the T transformation allows for closed‐loop and sensorless control system simulation with asymmetric machine due to broken rotor. Compensating effect of the closed‐loop control system with speed measurements and diagnosis information in control system variables are identified. Proposed frequency analysis of state observers is presented and applied. Variables with amplified characteristic frequency components related to rotor asymmetry are compared for selected structures of state observers and with closed‐loop and open‐loop operation. Method of improving the sensorless system stability is proposed.Practical implicationsIn closed‐loop and sensorless control system rotor fault can be diagnosed by using PI output controllers variables. Compensating effect of mechanical variables sets limitation to specified diagnosis methods. Rotor asymmetry affects sensorless control system stability depending on estimator structure.Originality/valueThis paper concentrates upon sensorless control system operation with machine asymmetry and indicates rotor fault symptoms.
Application of MLP and RBF neural networks in the control structure of the drive system with elastic joint
Authors: Orlowska‐Kowalska Teresa , Kaminski Marcin 
Published: May 2009

PurposeThe purpose of this paper is to obtain an estimation of not measured mechanical state variables of the drive system with elastic coupling between the driven motor and a load machine, using neural networks (NN) of different type for the sensorless drive system.Design/methodology/approachThe load‐side speed and the torsional torque are estimated using multi‐layer perceptron (MLP) and radial basis function (RBF) networks. The special forms of input vectors for neural state estimators were proposed and tested in open‐ and closed‐loop control structure. The estimation quality as well as sensitivity of neural estimators to the changes of the inertia moment of the load machine were evaluated and compared.FindingsIt is shown that an application of RBF‐based neural estimators can give better accuracy of the load speed and torsional torque estimation, especially for the proper choice of the input vector of NN, also in the case of a big change of the load machine time constant.Research limitations/implicationsThe investigation and comparison is based on simulation tests and looked mainly at the quality of state variable estimation while the realisation cost in parallel processing devices (FPGA) still need to be addressed.Practical implicationsThe proposed neural state variable estimators of two‐mass system can be practically implemented in the control structure of two‐mass drive with additional feedbacks from load machine speed and torsional torque, which results in the successive vibration damping.Originality/valueThe application of RBF neural state estimators for two‐mass drive and their comparison with commonly used MLP‐based estimators, as well as testing of both type of NN in the closed‐loop control structure with additional feedbacks based on state variables estimated by neural estimators.
Numerical modeling of 3‐D comb drive electrostatic accelerometers structure (method of levitation force reduction)
Authors: Wiak Sławomir , Smółka Krzysztof 
Published: May 2009

PurposeThe purpose of this paper is to discuss the numerical modelling of 3D structure of micro‐electro‐mechanical systems (MEMS) accelerometers. The general idea being discussed is the method of levitation force reduction, as the main source of incorrect mathematical model of comb drive structure.Design/methodology/approachAccelerometers design is a highly interdisciplinary area and, therefore, different methods and tools have to be exploited. Dynamic accelerometer behaviour modelling has been performed by use of a new object‐oriented model (NOOM), based on complex computer field and mechanical models.FindingsThe paper describes methods of levitation force reduction in electrostatic comb drive structures based on electrostatic structural models and finite elements method.Research limitations/implicationsIn the present work, the authors limit themselves to the electrostatic energy domains.Practical implicationsBoth, mechanical and electric models of accelerometers give the input data for defining the object‐oriented model, based on Matlab‐Simulink platform, fulfilling the general demand of dynamic behaviour simulation of comb drive structure. The proposed by authors methodology could give valuable contribution to MEMS design methodology.Originality/valueA new methodology has been successfully applied to calculation of levitation force in different geometries of comb drive. This methodology could be useful for multidisciplinary MEMS systems.
Modelling dynamic hysteresis loops in steel sheets
Authors: Chwastek Krzysztof , Szczygłowski Jan , Wilczyński Wiesław 
Published: May 2009

PurposeThe aim of the paper is to present a simple approach to modelling minor hysteresis loops in grain‐oriented steel sheets under quasi‐static and dynamic conditions. The hysteresis phenomenon is described with a recently developed hybrid model, which combines ideas inherent in the product Preisach model and the Jiles‐Atherton description. The dynamic effects due to eddy currents are taken into account in the description using a lagged response with respect to the input.Design/methodology/approachIt is assumed that some model parameters might be dependent on the level of relative magnetization within the material. Their dependencies could be given as power laws. The values of scaling coefficients in power laws are determined.FindingsA satisfactory agreement of experimental and modelled quasi‐static and dynamic hysteresis loops is obtained.Research limitations/implicationsThe present study provides a starting point for further verification of the approach for other classes of soft magnetic materials, which could be described with the developed model. At present, the approach to model minor loops by the update of model parameters is verified for the B‐sine excitation case.Practical implicationsThe “branch‐and‐bound” optimization algorithm is a useful tool for recovery of the values of both model parameters and scaling coefficients as well.Originality/valueThe recently developed hybrid description of hysteresis phenomenon can be successfully extended to take into account symmetric minor loops. The developed approach could be a framework to develop a comprehensive description of magnetization phenomena in the future.
Numerical modelling of non‐linear coupled thermo‐electric problems
Authors: Golosnoy Igor O. , Sykulski Jan K. 
Published: May 2009

PurposeThe purpose of this paper is to access performance of existing computational techniques to model strongly non‐linear coupled thermo‐electric problems.Design/methodology/approachA thermistor is studied as an example of a strongly non‐linear diffusion problem. The temperature field and the current flow in the device are mutually coupled via ohmic heating and very rapid variations of electric conductivity with temperature and applied electric field, which makes the problem an ideal test case for the computational techniques. The finite volume fully coupled and fractional steps (splitting) approaches on a fixed computational grid are compared with a fully coupled front‐fixing method. The algorithms' input parameters are verified by comparison with published experiments.FindingsIt was found that fully coupled methods are more effective for non‐linear diffusion problems. The front fixing provides additional improvements in terms of accuracy and computational cost.Originality/valueThis paper for the first time compares in detail advantages and implementation complications of each method being applied to the coupled thermo‐electric problems. Particular attention is paid to conservation properties of the algorithms and accurate solutions in the transition region with rapid changes in material properties.
TESTCASE: a benchmark problem for coupled field‐circuit simulations
Authors: van der Giet M. , Lange E. , Hameyer K. 
Published: May 2009

PurposeThe purpose of this paper is to present an experimental setup for the verification of coupled electromagnetic field‐circuit simulation, called TESTCASE. By means of simple and well‐defined geometries, the comparison of different coupling approaches among each other and with measurements should be possible.Design/methodology/approachThe physical setup consists of a C‐core in conjunction with a reluctance rotor. The TESTCASE is designed to work in static operation and with motion induced voltage.FindingsSimulation results using different approaches as well as measurement results are presented. Practical issues in measurement and simulation are discussed. It was found that particular care has to be taken concerning the modeling of the air around the TESTCASE structure.Originality/valueWith the proposed approach, it is possible to evaluate the coupled field circuit problem on a defined and well‐known geometry. Simulation results can be compared to measurements.