Aqueous-Base-Developable Benzocyclobutene (BCB)-Based Material -An Emerging Dielectric Material for Microelectronics

A self-priming and photosensitive aqueous-base-developable benzocyclobutene (BCB)-based dielectric material curable in air is described. The polymer is made from divinylsiloxane benzocyclobutene and BCB-acrylic acid. Patterned films have high resolution, and via openings are scum-free without a descum operation. Whether cured in nitrogen or in air, the formulation produces a film with optical, electrical, thermal, and mechanical properties desired for many microelectronic applications, such as packaging applications and a planarization layer or insulation layer in display applications

Denotative and Connotative Semantics in Hypermedia: Proposal for a Semiotic-Aware Architecture

In this article we claim that the linguistic-centered view within hypermedia systems needs refinement through a semiotic-based approach before real interoperation between media can be achieved. We discuss the problems of visual signification for images and video in dynamic systems, in which users can access visual material in a non-linear fashion. We describe how semiotics can help overcome such problems, by allowing descriptions of the material on both denotative and connotative levels. Finally we propose an architecture for a dynamic semiotic-aware hypermedia system

The Effects of Two Types of Sleep Deprivation on Visual Working Memory Capacity and Filtering Efficiency

Sleep deprivation has adverse consequences for a variety of cognitive functions. The exact effects of sleep deprivation, though, are dependent upon the cognitive process examined. Within working memory, for example, some component processes are more vulnerable to sleep deprivation than others. Additionally, the differential impacts on cognition of different types of sleep deprivation have not been well studied. The aim of this study was to examine the effects of one night of total sleep deprivation and 4 nights of partial sleep deprivation (4 hours in bed/night) on two components of visual working memory: capacity and filtering efficiency. Forty-four healthy young adults were randomly assigned to one of the two sleep deprivation conditions. All participants were studied: 1) in a well-rested condition (following 6 nights of 9 hours in bed/night); and 2) following sleep deprivation, in a counter-balanced order. Visual working memory testing consisted of two related tasks. The first measured visual working memory capacity and the second measured the ability to ignore distractor stimuli in a visual scene (filtering efficiency). Results showed neither type of sleep deprivation reduced visual working memory capacity. Partial sleep deprivation also generally did not change filtering efficiency. Total sleep deprivation, on the other hand, did impair performance in the filtering task. These results suggest components of visual working memory are differentially vulnerable to the effects of sleep deprivation, and different types of sleep deprivation impact visual working memory to different degrees. Such findings have implications for operational settings where individuals may need to perform with inadequate sleep and whose jobs involve receiving an array of visual information and discriminating the relevant from the irrelevant prior to making decisions or taking actions (e.g., baggage screeners, air traffic controllers, military personnel, health care providers)

Associations between physical activity types and multi-domain cognitive decline in older adults from the Three-city cohort

Several studies suggest that physical activity improves cognitive functions and reduces cognitive decline, whereas others did not find any evidence of a neuroprotective effect. Furthermore, few cohort studies have analyzed the different physical activity types and particularly household activities. Our objective was to assess the association of two physical activity types with the decline in different cognitive domains in a large prospective cohort of community-dwelling older adults from the Three-city study. Physical activity (domestic/transportation activities and leisure/sport activities) was assessed with the Voorrips questionnaire, specific for older adults. Baseline sociodemographic and health history variables as well as cognitive performance data at baseline and during the 8-year follow-up (Mini-Mental State Examination, Benton Visual Retention Test, Trail Making Tests A and B, Isaac's Set Test and Free and Cued Selective Reminding Test) were also available. Associations between physical activity scores and cognitive decline in different domains were tested using minimally- and multi-adjusted linear mixed models. The analysis included 1697 participants without dementia at baseline and with at least one follow-up visit. At baseline, participants with higher sub-scores for the two physical activity types had better cognitive performances. Interaction with time showed that decline in some cognitive scores (Trail Making Test B and Isaac's Set Test) was significantly less pronounced in participants with higher household/transportation activity sub-scores. No significant effect over time was found for leisure/sport activities. This study shows that during an 8-year follow-up, executive functions and verbal fluency were better preserved in older adults who performed household/transportation activities at moderate to high level. Participation in domestic activities and using adapted transport means could allow older adults to maintain specific cognitive abilities

Rueckhaltung von Amalgamabfaellen aus Zahnarztpraxen Abschlussbericht

TIB: RO 1602 (44)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Anodic bonding at low voltage using microstructured borosilicate glass thin-films

The use of borosilicate glass for anodic wafer bonding to silicon is well established in industry. In this paper we present a matured approach, where a microstructured borosilicate glass thin-film instead of a bulk glass wafer is used as anodic bond layer. A glass layer with a thickness of 3-5 m is sufficient for a stable bond at very moderate bond parameters with bond voltages in the range of 30-60 V at standard bond temperatures of around 300°C and below. This enables the use of anodic bonding also for sensitive devices

Prospects and limits in wafer-level-packaging of image sensors

The ongoing efforts of increasing the resolution of image sensors for consumer products and the simultaneous demand for small camera systems led to a miniaturization in pixel sizes down to 1.4 µm. This technological progress enables the fabrication of high pixel count imagers with comparably small dimensions (e.g. 9 MPix with 4.88 mm × 3.66 mm / 3 MPix with 2.86 mm × 2.15 mm). Further on, besides the impact of the pixel size on the lateral dimensions of the imager, manufacturing and packaging issues of the optical components and their integration with the imager influence the miniaturization. There are two effects which determine the lower limit of reasonable pixel miniaturization. Firstly, the increasing single-to-noise characteristics of the pixel leading to noisy images especially perturbing under low light conditions. Secondly, the diffraction limits which determines the smallest possible spot size when using a "perfect" lens without any spot blurring aberrations. As the latter depends from the f-number of the system, pixel miniaturization demands high speed lenses (low f-numbers) which additionally complicates the optical design and challenges their fabrication. The enabling key technology for wafer level packaging of camera systems based on top-side illuminated imagers are Through Silicon Vias (TSV) because they allow a redistribution on the backside of the wafer wherefore the active side remains unaffected and can be completely used for the optic assembly. Due to comparably relaxed pitches of the contact pads of mostly more than 100 µm in most imaging applications, tapered vias with a polymer passivation are the straight forward approach and an economic reasonable TSV technology. Spray coating of polymers allows the use of low cure temperature materials also with severe topographies while spin coating can be a low cost alternative for applications where low silicon thicknesses of 40 µm and below are allo- - wed. Wafer bonding is the bridging technology which finally has to integrate the optics and the sensor part. Wafer stacks of up to a few millimeters have to be handled which can exhibit topographies on their backside while maintaining an accurate alignment of better than 5 µm. The fabrication of camera packages using only wafer level technologies gets more complex and expensive the bigger the vertical dimension and/or the aspect ratio or shape of its comprising features becomes. The demands for a system integration on wafer level scales therefore with increasing pixel number and I/O - density. This paper outlines the prospects and limits of state of the art wafer-level-packaging technology for image sensor packaging with respect to the optical design. A process chain is presented for a micro camera device which was completely fabricated on wafer level having a die size of about 1 mm × 1 mm

Rueckhaltung von Amalgamabfaellen aus Zahnarztpraxen Abschlussbericht. Abschlussdatum: 30.04.1986

TIB: RN 8908 (86-057) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Assessing fitness to drive in older adults: Validation and extension of an economical screening tool

Schulz P, Beblo T, Spannhorst S, et al. Assessing fitness to drive in older adults: Validation and extension of an economical screening tool. Accident Analysis & Prevention. 2020;149: 105874.OBJECTIVES: Due to demographic change, the number of older drivers with impaired driving skills will increase in the next decades. The current study aimed at the validation and extension of the screening tool Safety Advice For Elderly drivers (SAFE) that allows a cost-efficient assessment of driving-related risk factors in older drivers.; METHOD: Seventy-four older drivers aged ≥65 years (M=77 years) recruited from the general population were included in this prospective observational study. Receiver operating characteristic curve (ROC) and hierarchical logistic regression analyses were utilized to examine whether the SAFE and further evidence-based driving-related factors may allow the differentiation between fit and unfit older drivers assessed in standardized on-road driving assessments.; RESULTS: ROC analyses revealed significant diagnostic accuracy of the number of SAFE risk factors in differentiating between fit and unfit older drivers (AUC=0.71). A stepwise logistic regression model revealed that adding further evidence-based risk factors into the SAFE clearly improved diagnostic accuracy (AUC=0.85).; DISCUSSION: The current study shows that the risk assessed by the SAFE predicts on-road driving fitness in older adults. However, the results also suggest a need for a modification of the SAFE by the inclusion of additional evidence-based risk factors. With sensitivity and specificity scores of about 90 % and 75 %, this modified version may be more suitable for clinical use. Copyright © 2020 Elsevier Ltd. All rights reserved

Innovative excimer laser dual damascene process for ultra-fine line multi-layer routing with 10 µm pitch micro-vias for wafer level and panel level packaging

The demands of higher routing density on wafer level are driven by multi-chip integrated fan-out packages and high I/O CSPs. New technologies and materials are necessary to generate lines and spaces down to 2 μm. Multi-metal layers are necessary for the higher wiring effort on panel level packaging (PLP) for example to contact dies which are embedded together. This places higher demands on the mechanical properties of the materials that are used for the redistribution layer. This paper presents a new excimer laser-enabled dual damascene process for ultra-fine routing for BEOL which was developed in a joint project with SUSS MicroTec. In the project, various materials e.g. low temperature cure polyimide, BCB and dry-film ABF materials were structured by using an excimer laser stepper with a reticle mask to pattern feature sizes below 4 μm with a high throughput. Micro-vias with a diameter below 5 μm were ablated with an aspect ratios up to 4 which is exceeding the photolithographic resolution limits of the established photosensitive thin-film polymers. The laser structuring allows the usage of innovative dielectric materials for WLPs/PLPs with optimized mechanical and electrical parameters, for example polymers with inorganic fillers like dry-film ABF material. Also, the ablations depth per laser pulse was investigated. The ablated lines and micro-vias were metallized by applying a galvanic process and CMP. The stepper-like system allows a sub-micron alignment accuracy with no need of a capture pad in the redistribution layers. Test multi-layer structures have been designed and fabricated with lines and spaces below 10 μm to demonstrate the dense routing capability with an excellent reliability which was verified by air-to-air thermal cycling (from -55 °C up to 125 °C)