72 research outputs found
Do Firms Benefit from Being Present in Multiple Technology Clusters? An Assessment of the Technological Performance of Biopharmaceutical Firms
Firms active in knowledge-intensive fields are increasingly organizing their R&D activities on an international scale. This paper investigates whether firms active in biotechnology can improve their technological performance by developing R&D activities in multiple technology clusters. Regions in the US, Japan and Europe, that host a concentration of biotechnology activity are identified as clusters. Fixed-effect panel data analyses with 59 biopharmaceutical firms (period 1995-2002) provides evidence for a positive, albeit diminishing (inverted-U shape) relationship between the number of technology clusters in which a firm is present and its overall technological performance. This effect is distinct from a mere multi-location effect.region, clusters, biotechnology, technology clusters
Do firms benefit from being present in technology clusters? Evidence from a panel of biopharmaceutical firms.
This paper investigates whether firms active in biotechnology can improve their technological performance by developing R&D activities in technology clusters. Regions that host a concentration of biotechnology activity are identified as technology clusters (level of US states, Japanese prefectures and European NUTS2 regions). A fixed effect panel data analysis on a set of 59 biopharmaceutical firms (period 1995-2002) provides evidence for a positive, albeit diminishing (inverted-U shape) relationship between the number of technology clusters in which a firm is present and its total technological performance. This effect is distinct from a mere multi-location effect.Cluster; Innovation; Biotechnology;
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
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 ÎĽm 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
Flipchip bonding of thin Si dies onto PET foils: possibilities and applications
Low cost large area flexible electronic products are expected to be used in a wide range of applications and in large quantities in our society. Examples of this include sensor packages added to food or conformal intelligent patches that monitor a patient's well-being. Because of their large area, the preferred substrate material for these applications will be low cost materials like polyesters (PEN/PET). Intelligence or communicative capabilities are preferably added to these devices by integrating the chips directly on the low cost foil itself. To maintain the flexibility of the package and not to add too much to the thickness, the Si chip needs to be integrated into the product as a bare, thinned die. Flip chip bonding is currently the most mature, widely available technology to integrate these thin chips. The low temperature stability of the PET foils however puts serious constraints on the materials and the process. The current paper specifically addresses the challenges associated with this. Initial results from a finite element model will be discussed. The model is being developed to understand the influence of the bonding process and material parameters on the final stresses and warpage of the chip. Additionally, lifetime and flexural test results will be discussed of ultrathin chips bonded on Cu and Ag-based screen printed circuitry. Finally, some applications of the technology will be shown: a microcontroller integrated on a Cu-PET foil and a supply chain monitoring tag
Technology development for a low-cost, roll-to-roll chip embedding solution based on PET foils
The aim of the research described in this paper is to develop a low-cost, roll-to-roll compatible process for the realization of electronic systems in foil using chip embedding. The small cost makes these systems suitable for disposable applications as food labels, medicine packages or smart bandages. Surface mount attaching of components on foils is a well-known process for building systems-in-foil. When using low-cost films like PEN and PET, there are serious restrictions on the maximum temperatures that can be used for the surface mounting process (soldering, adhesive bonding). Surface mounting has the additional disadvantage that the components are on the surface of the foil and are therefore not well protected mechanically and physically. The proposed process flow for embedding thin chips in PET foils overcomes these limitations. A key aspect of this technology is the application of a suitable adhesive to encapsulate the chips. The resulting product is based on full-metal copper which has a good thermal and electrical conductivity and allows for fine pitches. The process is compatible with several metal foils (Cu, Al …), offering further possibilities in cost reduction, and does not rely on bumping of the chips or plating of the interconnections to the chips
Bonding bare die LEDs on PET foils for lighting applications: thermal design modeling and bonding experiments
Integration of LEDs on flexible foil substrates is of interest for flexible lighting applications and flexible photonic devices. A matrix of LEDs on a foil combined with a diffuser can be a potential alternative for flexible OLED lighting devices. Preferably, these LEDs are integrated in an unpackaged, bare die form as it reduces cost, footprint and thickness. As a substrate, preferably low cost materials like polyesters (PET) are being used, especially for large area devices. However, the use of these materials imposes some limitations. Most notably, the low temperature stability (<100 degrees C continuous use temperature) of these materials limits the maximum temperatures during the manufacturing process and poses constraints on the thermal design of the device. The current paper describes the results of research on possibilities for integrating bare die LEDs with low cost flexible PET foils. Finite element (FE) thermal modeling has been performed of possible designs of adhesively bonded LED-on-foil and laminated LED-in-foil configurations. The role of the different materials and the effect of their geometries on the temperature distribution in the simulated devices are discussed. The results give insight in measures that can be taken to keep the temperature of all the components of the device within operational limits. For LEDs bonded on Cu-PET foil the modeled temperature distributions are compared to experimentally observed temperature distributions in LED on PET foil reference devices using infrared thermal imaging. Besides this, initial studies on directly bonding LEDs on etched Cu on PET substrates using anisotropic conducting adhesives and isotropic conducting adhesives were performed. An experimental comparison is made between the different techniques based on temperature/humidity reliability and flexural stability of the bonded LEDs, based on these preliminary results
Hybrid integration on low-cost flex foils using photonic flash soldiering
Soldering of packaged electronic components using industry standard Sn-Ag-Cu (SAC) lead-free solders on low-cost foils, which are often the substrate of choice for flexible electronics, is challenging. This is mainly originating from the fact that the reflow temperatures of these solder alloys are normally higher than the maximum processing temperature of the low-cost flex foils. To enable component integration on the low-cost foils a novel method for soldering has been introduced by Holst Centre as an alternative to oven reflow, termed 'photonic soldering'. In this method high intensity photonic flashes are used to deliver the thermal energy required for soldering. By taking advantage of the selectivity of light absorption, the required energy for soldering is delivered to the components and circuit tracks while excessive heating of the foils is avoided. This paper presents successful photonic flash soldering of packaged LED components on low-cost polyethylene terephthalate (PET) foils using conventional SAC solders as a demonstration of the capabilities of this novel soldering technology
Analysing the Control Software of the Compact Muon Solenoid Experiment at the Large Hadron Collider
The control software of the CERN Compact Muon Solenoid experiment contains
over 30,000 finite state machines. These state machines are organised
hierarchically: commands are sent down the hierarchy and state changes are sent
upwards. The sheer size of the system makes it virtually impossible to fully
understand the details of its behaviour at the macro level. This is fuelled by
unclarities that already exist at the micro level. We have solved the latter
problem by formally describing the finite state machines in the mCRL2 process
algebra. The translation has been implemented using the ASF+SDF
meta-environment, and its correctness was assessed by means of simulations and
visualisations of individual finite state machines and through formal
verification of subsystems of the control software. Based on the formalised
semantics of the finite state machines, we have developed dedicated tooling for
checking properties that can be verified on finite state machines in isolation.Comment: To appear in FSEN'11. Extended version with details of the ASF+SDF
translation of SML into mCRL
NikR mediates nickel-responsive transcriptional induction of urease expression in Helicobacter pylori
The important human pathogen Helicobacter pylori requires the abundant
expression and activity of its urease enzyme for colonization of the
gastric mucosa. The transcription, expression, and activity of H. pylori
urease were previously demonstrated to be induced by nickel
supplementation of growth media. Here it is demonstrated that the HP1338
protein, an ortholog of the Escherichia coli nickel regulatory protein
NikR, mediates nickel-responsive induction of urease expression in H.
pylori. Mutation of the HP1338 gene (nikR) of H. pylori strain 26695
resulted in significant growth inhibition of the nikR mutant in the
presence of supplementation with NiCl(2) at > or =100 microM, whereas the
wild-type strain tolerated more than 10-fold-higher levels of NiCl(2).
Mutation of nikR did not affect urease subunit expression or urease enzyme
activity in unsupplemented growth media. However, the nickel-induced
increase in urease subunit expression and urease enzyme activity observed
in wild-type H. pylori was absent in the H. pylori nikR mutant. A similar
lack of nickel responsiveness was observed upon removal of a 19-bp
palindromic sequence in the ureA promoter, as demonstrated by using a
genomic ureA::lacZ reporter gene fusion. In conclusion, the H. pylori NikR
protein and a 19-bp operator sequence in the ureA promoter are both
essential for nickel-responsive induction of urease expression in H.
pylori
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