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The paper presents a mathematical problem involving quasistatic contact between a thermo-electro-viscoelastic body and a lubricated foundation, where the contact is described using a version of Coulomb’s law of friction that includes normal damped response conditions and heat exchange with a conductive foundation. The constitutive law for the material is thermo-electro-viscoelastic. The problem is formulated as a system that includes a parabolic equation of the first kind for the temperature, an evolutionary elliptic quasivariational inequality for the displacement and a variational elliptic equality for the electric stress. The author establishes the existence of a unique weak solution to the problem by utilizing classical results for evolutionary quasivariational elliptic inequalities, parabolic differential equations and fixed point arguments.

The author establishes a variational formulation for the model and proves the existence of a unique weak solution to the problem using classical results for evolutionary quasivariational elliptic inequalities, parabolic difierential equations and fixed point arguments.

The author proves the existence of a unique weak solution to the problem using classical results for evolutionary quasivariational elliptic inequalities, parabolic difierential equations and fixed point arguments.

The author studies a mathematical problem between a thermo-electro-viscoelastic body and a lubricated foundation using a version of Coulomb’s law of friction including the normal damped response conditions and the heat exchange with a conductive foundation, which is original and requires a good understanding of modeling and mathematical tools.

The purpose of this paper is to develop a technological method of protection against electrical corrosion. One more way to protect the objects is to prevent the electrical current from getting to them. For example, railway objects are surrounded with a material with raised electrical resistance.

The railway infrastructure objects (foundations, contact-line supports, reinforced concrete sub-bases, bridge structures, pipelines of engineering networks, supports of passenger platforms and pedestrian bridges, concrete plinth walls of station buildings) are subjected to destruction due to the action of electrical current. One of destruction factors is a corrosion of the concrete constructions which is caused by the leakage current action.

Leakage currents and stray currents bypass the structure of supports of high passenger platforms or pipes of engineering networks. These currents spread by the line with the least resistance outside of the structures.

Electrical leakage current from the rails gets into such structures through sleepers, ballast and soil and leads to accelerated corrosion leaching of concrete.

The constructions are protected against the destructive effect of electrical corrosion on the metal or concrete of the structure. This scheme is suitable for the construction and reconstruction of railway structures which operate on electrified sections of railways.

Schemes of technological solution are proposed for protection of foundations, supports of high passenger platforms, pipelines of engineering networks, etc. For this, the arrangement of soil-contained screens with big electrical resistance is suggested.

The authors propose a theoretical basis for understanding the role of ecosystem intermediaries in the configuration of social entrepreneurship identities in social purpose organisations (SPOs) and their business model innovations (BMIs).

Adopting a retrospective multiple-case study, the authors offer insights into the paths/elements that determine the building of 44 social entrepreneurship identities in the context of an emerging economy (Mexico).

The study sheds light on the role of intermediaries in the configuration of the entrepreneurial identities of Mexican SPOs and BMIs, as well as several externalities generated during the process of capturing the social and economic value, especially when social innovations are focussed on solving societal, economic and ecological social problems.

The first limitation is related to the analysis of intermediaries within the social entrepreneurship ecosystem, which needs more conceptual and empirical evidence. The second limitation is that the analysis focussed only on intervened SPOs, as the authors did not control for non-intervened SPOs. Thus, this allows for future in-depth analysis of intermediary efficiency in a focus group (intervened SPOs) and a control group (non-intervened SPOs).

The study also provides insights for Mexican SPOs on how a social entrepreneurship identity helps to capture the value creation of social innovations within an innovation ecosystem. Indeed, it is strongly aligned with the United Nations' Social Development Goals.

The study enhances the discussion about how intermediaries could encourage social entrepreneurial identity, as well as how intermediary intervention could facilitate the design and implementation of BMIs in the innovation ecosystem.

The three-dimensional arrangement structure of the conductive fiber is an important factor of the shielding effectiveness of the electromagnetic shielding fabric (EMSF). However, until now, the three-dimensional arrangement structure has not been described because of the complex structure, which leads to many difficulties for the subsequent analysis of the electromagnetic characteristics. Therefore, the purpose of this paper is to propose a feature extraction method to describe the arrangement structure of the conductive fiber based on the three-dimensional calibration and image processing technology, providing a new idea for the above problem.

First, the three-dimensional positions of the conductive fibers in the EMSF are calibrated using the VHX-600 3D digital microscope and the MATLAB7.5 software. The arrangement characteristics of the conductive fibers are analyzed, and equivalent twist, cross-sectional content, and average angle of a single fiber are proposed to describe the arrangement characteristic of the conductive fiber. Then, a digital description model of the conductive fiber is constructed according to the feature parameters and its three-dimensional structures are reproduced using CATIA. Finally, the reliability of the model is verified by an FDTD example, and the significance and application of the model are given.

The proposed method can provide the feature extraction and description for the complex spatial three-dimensional arrangement structure of conductive fibers. The feature parameters can reflect different micro arrangement features of the conductive fiber. The proposed idea and method can provide a solid foundation for subsequent studies of the electromagnetic properties of the EMSF.

The study in this paper is of great significance and academic value. This paper provides a new three-dimensional calibration method and constructs multiple feature parameters to describe the complex three-dimensional arrangement structure, providing a new effective method to overcome the problem of the conductive fiber description. The proposed method provides an important basis for the shielding mechanism, transmission characteristics, electromagnetic calculation and product design, and woven technology of the EMSF.

The purpose of this paper is to form high density interconnection (HDI) of backboard for press-fit applications with the pre-curing conditions of conductive paste. The best condition of pre-curing conductive paste should be found to obtain good electrical and physical performance of the conductive paste and avoid the simultaneous curing behavior of prepreg.

A novel structure of backboard was designed by using the connection of conductive paste-filled through holes to connect two multilayers. Pre-curing conditions of conductive paste were investigated to find their effects on resistance, bond strength and volume shrinkage. The reliability of pre-curing conductive paste was also analyzed.

Pre-curing conditions led to a great influence on the resistance, bond strength and volume shrinkage of the conductive paste. The best condition of pre-curing conductive paste was chosen as the low curing temperature of 60°C and a curing time of 30 min. Cured conductive paste exhibited square resistance of 4.205 mΩ/□ and bonding strength of 22.86 N. The as-obtained pre-curing condition could improve the reliability of conductive paste. Pre-curing process of conductive paste at extremely low temperature to interconnect two multilayer structures improved the density interconnection of backboard for press-fit applications.

The use of HDI of backboard could lead to good assembly for high-speed signal transmission of electronic products with press-fitting components. The connection of pre-curing conductive paste for multilayers could have important function for improving the application for communication backboard.

In recent years, electronic devices have increasingly employed printed circuits produced using electrically conductive adhesives, commonly known as polymer thick films. This method is much more cost‐effective and efficient than other methods of wiring, including those using chemical etching or plating. In the past, the use of metal‐filled polymers as conductors in printed circuit fabrication has suffered from several limitations such as poor solderability, conductivity and adhesion. A new electrically conductive metal‐filled polymer formulation has been developed which overcomes these problems inherent in typical polymer thick film inks. This new product is based on transient liquid‐phase sintering wherein the metallic components of the formulation sinter at a relatively low temperature, resulting in a highly conductive continuous metal network. The sintering is achieved through the interaction of several metallic components with an adhesive‐flux component. The final product is highly conductive, solderable and exhibits excellent adhesion to a wide range of substrate materials. A new process for manufacturing fine‐line printed circuit boards using this ink technology is under investigation. It promises potentially simpler processing and lower cost than plating. In this new process, traces (in the form of troughs in the dielectric) are imaged using conventional photoimageable dielectrics. Exposure and developing conditions depend upon the polymer system used. The transient liquid phase sinterable conductive ink is applied to fill the photo‐exposed conductor pattern. Next, another layer of photoimageable dielectric is applied over the traces and imaged with vias for interconnections with subsequent layers. The dielectric is then cured and the ink applied to fill the vias. These steps may be repeated several times to produce low‐profile fine‐line multilayer printed circuits. This process for producing multilayer circuits using conductive inks simplifies the manufacturing of printed circuits, reduces profile, eliminates most waste in manufacturing, and reduces cost compared with plating.

The purpose of this paper is to explore the possibility of integrating inkjet printed circuitry with fused deposition modeling (FDM) structures to produce embedded electronics and smart structures. Several of the challenges of combining these technologies are identified, and potential solutions are developed.

An experimental approach is taken to investigate some of the relevant physical processes for integrating FDM and inkjet deposition, including the printing, drying and sintering processes. Experimental data are collected to assist understanding of the problems, and engineering solutions are proposed and implemented based on the gained understanding of the problems.

Three challenges have been identified, including the discontinuity of the printed lines resulting from the irregular surface of the FDM substrate, the non-conductivity of the printed lines due to the particle segregation during the droplet drying process and the slow drying process caused by the “skinning effect”. Two engineering solutions are developed for the discontinuity problem. The non-conductivity issue and the slow drying process are attributed to the motion of the nanoparticles caused by the evaporation flow. The thermally activated drying process for the Cabot ink suggests that the proposed solution is effective. Timescale analysis and experimental data show that the printing conditions do not have a clear influence on the conductivity of the printed lines, and drying and sintering processes are more important.

No quantitative model has yet been developed for simulating the printing, drying and sintering processes associated with inkjet printing on FDM substrates. Quantitative models can be extremely valuable for improvement in understanding the problems, optimizing the proposed solutions and coming up with better solutions.

The research findings in this work have great implications in implementing a hybrid FDM-inkjet deposition machine for fabricating embedded electronics and smart structures. All the proposed engineering solutions for the identified problems can be potentially integrated into one machine.

The success of the integration of the FDM and inkjet deposition process will enable the design of compact electro-mechanical structures to replace the large heavy electro-mechanical systems.

This work represents one of the first attempts for integrating inkjet deposition of silver nanoparticle inks with the FDM process for making compact electro-mechanical structures. Three critical challenges are identified, and corresponding engineering solutions are proposed and implemented based on analysis of the relevant physical processes, including the printing, drying and sintering processes, which has laid the foundation for integrating the FDM and inkjet deposition processes.

The purpose of this paper is to present an exhaustive review of research studies and activities in the inkjet printing of conductive materials.

This paper gives a detailed literature survey of research carried out in inkjet printing of conductive materials.

This article explains the inkjet printing process and the various types of conductive inks. It then examines the various factors that affect the quality of inkjet printed interconnects such as printing parameters, materials and substrate treatments. Methods of characterising both the inkjet printing process and the electrical properties of printed conductive materials are also presented. Finally relevant applications of this technology are described.

Inkjet printing is currently one of the cheapest direct write techniques for manufacturing. The use of this technique in electronic manufacturing, where interconnects and other conductive features are required is an area of increasing relevance to the fields of electronics manufacturing, packaging and assembly. This review paper would therefore be of great value and interest to this community.

The purpose of this paper is to improve understanding of how different aspects of the national institutional environment may influence the extent of innovative entrepreneurial activities across countries. Several institutional and conductive factors affecting a country’s capacity to support innovative entrepreneurship are explored.

Institutional theory is used to examine the national regulatory, normative, cognitive and conducive aspects that measure a country’s ability to support innovative entrepreneurship. A cross-national institutional profile is constructed to validate an entrepreneurial innovation model. The impacts of country-level national institutions on innovative entrepreneurial activity as measured by Global Entrepreneurship Monitor data are assessed through structural equation modeling.

Knowledge about the influence of specific institutional aspects on innovative entrepreneurship, and hence of institutional structures within and across countries, is enhanced. For new innovative enterprises, conductive and regulatory aspects seem to matter most. All conductive factors have a significant and positive impact on entrepreneurial activity rates.

Results could support policy makers and practitioners in evaluating government policies’ effects on innovative entrepreneurship. Interventions should target both individual attributes and context. Future research could include longitudinal designs to measure the direction of causality.

Aspects such as regulatory institutions, and conductive factors such as information communication technology use and technology adoption, are important for innovation entrepreneurship development.

The literature on institutional theory and innovative entrepreneurship is highly limited. This study complements growing interest in empirical analysis of the effects of national institutions on innovative entrepreneurial activities and substantiates previous empirical work.

This review paper aims to provide a better understanding of formulation and processing of anisotropic conductive adhesive film (ACF) material and to summarize the significant research and development work for the mechanical properties of ACF material and joints, which helps to the development and application of ACF joints with better reliability in microelectronic packaging systems.

The ACF material was cured at high temperature of 190°C, and the cured ACF was tested by conducting the tensile experiments with uniaxial and cyclic loads. The ACF joint was obtained with process of pre-bonding and final bonding. The impact tests and shear tests of ACF joints were completed with different aging conditions such as high temperature, thermal cycling and hygrothermal aging.

The cured ACF exhibited unique time-, temperature- and loading rate-dependent behaviors and a strong memory of loading history. Prior stress cycling with higher mean stress or stress amplitude restrained the ratcheting strain in subsequent cycling with lower mean stress or stress amplitude. The impact strength and adhesive strength of ACF joints increased with increase of bonding temperature, but they decreased with increase of environment temperature. The adhesive strength and life of ACF joints decreased with hygrothermal aging, whereas increased firstly and then decreased with thermal cycling.

This study is to review the recent investigations on the mechanical properties of ACF material and joints in microelectronic packaging applications.