An inkjet printing-based process chain for conductive structures on printed circuit board materials

A process chain to fabricate conductive structures on printed circuit board material is presented in this thesis. This process chain comprises four main steps: plasma treatment, inkjet printing, electroless plating and functional characterisation. It represents a drastic reduction in the number of process steps when compared to the conventional lithography-based method, widely used in the printed circuit board industry

Active and passive component embedding into low-cost plastic substrates aimed at smart system applications

The technology development for a low-cost, roll-to-roll compatible chip embedding process is described in this paper. Target applications are intelligent labels and disposable sensor patches. Two generations of the technology are depicted. In the first version of the embedding technology, the chips are embedded in an adhesive layer between a copper foil and a PET film. While this results in a very thin (< 200 µm) and flexible system, the single-layer routing and the incompatibility with passive components restricts the application of this first generation. The double-sided circuitry embedding technology is an extension of the single-sided, foil-based chip embedding, where the PET film is replaced by a second metal foil. To obtain sufficient mechanical strength and to further reduce cost, the adhesive film is replaced by a substrate material which is compatible with the chip embedding concept. Both versions of the foil-based embedding technology are very versatile, as they are compatible with a broad range of polymer materials, for which the specifications can be tuned to the final application

Thermal control systems for low-temperature heat rejection on a lunar base

One of the important issues in the design of a lunar base is the thermal control system (TCS) used to reject low-temperature heat from the base. The TCS ensures that the base and the components inside are maintained within an acceptable temperature range. The temperature of the lunar surface peaks at 400 K during the 336-hour lunar day. Under these circumstances, direct dissipation of waste heat from the lunar base using passive radiators would be impractical. Thermal control systems based on thermal storage, shaded radiators, and heat pumps have been proposed. Based on proven technology, innovation, realistic complexity, reliability, and near-term applicability, a heat pump-based TCS was selected as a candidate for early missions. In this report, Rankine-cycle heat pumps and absorption heat pumps (ammonia water and lithium bromide-water) have been analyzed and optimized for a lunar base cooling load of 100 kW

Effect of liquid seaweed fertilizer of Sargassum wightii grev. on the growth and biochemical content of green gram (Vigna radiata (L.) R. wilczek)

Intensive investigations were made on the efficiency of Liquid Seaweed Fertilizer (LSF) obtained from the brown seaweed Sargassum wightii Grev. on the germination, growth and biochemical constituents of green gram (Vigna radiata (L.) R. Wilczek) under laboratory conditions and in pots. The seeds that are soaked for 6 hrs duration at lower concentrations such as 0.5% and 1.0% showed faster germination compared with the seeds that are soaked at higher concentration (2.0%) for long durations (12 hrs and 24 hrs). In pot studies, both the shoot length and root length were found to be increased as the concentration of LSF increases, but at high concentration i.e. at 2.0% concentration the growth was slightly reduced. Of the two different types of applications i.e. foliar and root applications, the foliar application was found to be more effective in determining the growth of the plant than the root application. Plants received with 1.0% concentration of LSF as foliar spray showed more shoot and root length, early flowering and more number of pods. The biochemical analysis of the experimental plants showed that the foliar treated plants showed more photosynthetic pigments compared to root treated plants, whereas the accumulation of total protein, total carbohydrate and total lipid content was found maximum in root treated plants than the foliar treated plants

Flip-chip bonding of fine-pitch ultra-thin chips for SiF applications

This paper describes the successful process investigations on ultrathin flip-chip bonding for fine-pitch applications on foil, using a novel bonding process involving Isotropic Conductive Adhesives (ICA). A Ag-based B-stage curing ICA was printed using state-of-the-art electroformed stencil on printed Ag circuitry, pre-cured and flip-chip bonded at low bonding force and short duration. The interconnection resistance measurements, performed before and after a stabilizing underfilling step, revealed low interconnect resistances down to 150 μm bond pad pitch. Finally, the reliability of the specimens prepared using this process was successfully evaluated by means of standard reliability test procedures such as thermal shock testing and accelerated humidity testing

MULTICAST VIRTUAL PRIVATE NETWORK PER-FLOW MONITORING FOR AN AGGREGATED TUNNEL IN A MULTIPROTOCOL LABEL SWITCHING CORE

Typically, when a service provider carries customer multicast traffic over a core network, it is often carried over a tunnel, which are often aggregated. There are many reasons for aggregated tunnel use, such as issues of scale and/or hardware limitations. While aggregated tunnels can be useful for carrying multicast traffic, it can be difficult to monitor network health when tunnels are aggregated. Techniques of this proposal provide for the ability to monitor network health by supporting per-flow counters for aggregated tunnels for both Internet Protocol (IP) version 4 and version 6 (IPv4/IPv6) traffic in a manner that is scalable and can be provided on-demand

Flexible and stretchable electronics for wearable healthcare

Measuring the quality of human health and well-being is one of the key growth areas in our society. Preferably, these measurements are done as unobtrusive as possible. These sensoric devices are then to be integrated directly on the human body as a patch or integrated into garments. This requires the devices to be very thin, flexible and sometimes even stretchable. An overview will be given of recent technology developments in this domain and concrete application examples will be shown