Digitally-Driven Hybrid Manufacture of Ceramic Thick-Film Substrates

Ceramic substrates are commonly used in the electronics industry across a range of applications such as automotive, aerospace, industrial monitoring, power electronics and electromagnetic devices due to their ability to withstand high temperatures, pressures, radiation and mechanical shock. This paper will present the development of a new digitally-driven hybrid manufacturing process which overcomes many of the current limitations of stand-alone Additive Manufacturing for the production of precision engineered ceramic substrates and packages. This is achieved by interleaving ceramic paste extrusion with sacrificial support printing and micro-machining to produce a three-dimensional ceramic green-state part. A number of substrates were fabricated using a high viscosity, non-Newtonian paste consisting of 96wt% alumina. Thermally processing the substrate at temperatures in excess of 1400 °C yields a monolithic ceramic substrate with resultant shrinkages of ∼18% and part densities of ∼99.8%. The 3D ceramic part is then processed using computer-controlled equipment to selectively dispense a conformal circuit using silver thick film conductor paste, followed by solder dispensing and pick and place surface mount assembly of components. This fully digitally driven approach enables new design freedoms and customization currently not possible with conventional template driven manufacturing methods of ceramic electronic packages

Extreme environment interconnects and packaging for power electronics

This paper presents the combination of an innovative assembly and packaging process utilising solid liquid inter diffusion (SLID) Cu-Sn interconnects within bespoke ceramic substrates that have been produced using additive manufacturing (AM). The resultant process chain supports the integration and packaging of power electronics for harsh environment applications. Here, the authors explore how the bond strength and composition of Cu-Sn SLID interconnects vary during exposure to thermal-mechanical load profiles. Samples of Cu-Sn are exposed to thermal loading up to 300°C and integrated mechanical loading via high random frequency vibrations (1 and 2000 Hz). In parallel, micro-extrusion printing methods in which high-viscosity ceramic pastes are dispensed through cylindrical fine nozzles (2–250 µm) using CNC-controlled motion has enabled complex 3D geometries to be fabricated. Additional secondary conductor deposition after firing the ceramic substrate enables the electronic circuitry to be generated without dedicated tooling, masks, or templates. This work presents the first fully 3D-printed ceramic-based electronic substrates. To demonstrate the applications of this printing method, a 555 timer circuit with flashing LED has been printed and the components surface mount assembled. The resultant ceramic substrates are dense, mechanically robust, and the reflowed circuit functions exactly as intended

Characterization of Cu-Sn SLID interconnects for harsh environment applications

This paper reports on the results obtained from performing 'shake and bake' testing on demonstrator vehicles bonded using Cu-Sn SLID technique. The demonstrator vehicles were exposed concurrently to vibration and thermal loadings similar to those seen in aerospace and downhole applications. This work demonstrates that Cu-Sn SLID bonding process is ideal for packaging sensors and electronics to be used within harsh environments, especially those encountered in the aerospace and oil & gas industries

IMPORTANCE OF IMPLEMENTING OPTIMAL LEARNING MANAGEMENT SYSTEMS FOR E LEARNING IN HIGHER EDUCATION Citation download: (BibTeX) (ris) (plaintext) IMPORTANCE OF IMPLEMENTING OPTIMAL LEARNING MANAGEMENT SYSTEMS FOR E LEARNING IN HIGHER EDUCATION

Over the last few years online education has shown a significant boom in Higher Education Institutions. Every day more and more universities are implementing their educational programs through this mode, offering opportunities for those people who cannot carry out their studies face to face. This educational mode offers a series of advantages, to highlight some of them for example, access to materials and content at any time and at any place, all that is needed is a computer and a connection to Internet; the students have an active role in their process of learning, meaning that they are not restricted recipients of information, but that it is part of their formative process; there is an authentic management of knowledge among students (exchange of ideas, opinions, practices, experiences); and feedback. After the analysis of different solutions, it's important to find the effects of how the correct selection of a learning management system make an impact in the academic performance of students, comparing, the needs of student use, the ease of the user interface, management, design, etc. [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Abstract Over the last few years online education has shown a significant boom in Higher Education Institutions. Every day more and more universities are implementing their educational programs through this mode, offering opportunities for those people who cannot carry out their studies face to face. This educational mode offers a series of advantages, to highlight some of them for example, access to materials and content at any time and at any place, all that is needed is a computer and an Internet connection; the students have an active role in their process of learning, meaning that they are not restricted recipients of information, but that it is part of their formative process; there is an authentic management of knowledge among students (exchange of ideas, opinions, practices, experiences); and feedback. Derived from the above, the number of students who carry out their studies under this educational mode has increased significantly, generating in Higher Education Institutions the need to acquire the appropriate technological infrastructure and the implementation of the most suitable Learning Management Systems (LMS) to fulfill the academic needs in this mode. In this sense, this research paper a comparative analysis is carried out between learning management systems with private software (Blackboard and WebCT) and of open source software (Moodle, Dokeos and Claroline). The parameters for comparison employed in this research, are the installation, personalization of the environment, functionality, resources management, groups and profiles, functionalities of Web 2.0 and the management of courses, in order to determine the optimum informatics solution for the implementation of educational programs in the mode of online education at the Computer Science Faculty of Mazatlan at the Autonomous University of Sinaloa. After the analysis of different solutions, it's important to find the effects of how the correct selection of a learning management system make an impact in the academic performance of students, comparing, the needs of student use, the ease of the user interface, management, design, etc