Design for Sub-PPM Testability of High-Voltage Mixed-Signal and Analog Integrated Circuits

Semiconductor processing and packaging technologies inevitably result in the fabrication of a number of integrated circuits (ICs) that fail to perform as designed, right after production or throughout their lifetime. The field of IC testing plays the role of filter between the market demanding fully functional electronic devices and the non-perfect manufacturing of ICs. While testing itself is not perfect and therefore has test escapes, the requirements in applications like automotive are tightening, demanding sub-ppm escape rates that even must approach the ppb level. This thesis investigates solutions to the problems of mixed-signal testing, especially automotive testing, that improve the quality of electronic devices reaching the end users. The thesis starts with introducing the challenges encountered in mixed-signal testing and the gaps between digital and analog testing, which provide the motivations for this research. The introduced problems are addressed from different angles in different chapters. First, validated DC fault models for open defects are presented, aiming to solve the lack of complete validated fault models for analog circuits. Then, a very-low-cost and highly-parallel design-for- testability (DfT) technique is introduced, providing a structured solution to the low fault coverage problem of the analog circuits by increasing the observability. Finally, a light-based non-intrusive and fully parallel method increasing the controllability in analog and mixed-signal circuits is explored, which presents promising results at very low test costs. The proposed methods exploit DC tests because of their ease of generation and application. Both proposed methods are validated with real industrial circuits from the automotive industry. The advantages as well as limitations of the proposed methods are described in detail, taking into account the possible implementation into industrial production testing. In conclusion, this thesis tackles the problems of today's mixed-signal testing by proposing different solutions, which are validated on industrial automotive circuits. The findings of the thesis, however, can easily be extended to mixed-signal circuits in general.status: publishe

Light-Driven Integration of Graphitic Carbon Nitride into Polymer Materials

As a metal-free polymeric semiconductor with an absorption in the visible range, carbon nitride has numerous advantages for photo-based applications spanning hydrogen evolution, CO2 reduction, ion transport, organic synthesis and organic dye degradation. The combination of g-C3N4 and polymer networks grants mutual benefit for both platforms, as networks are upgraded with photoactivity or formed by photoinitiation, and g-C3N4 is integrated into novel applications. In the present contribution, some of the recently published projects regarding g-C3N4 and polymeric materials will be highlighted. In the first study, organodispersible g-C3N4 were incorporated into a highly commercialized porous resin called poly(styrene-co-divinylbenzene) through suspension photopolymerization, and performances of resulting beads were investigated as recyclable photocatalysts. In the other study, g-C3N4 nanosheets were embedded in porous hydrogel networks, and so-formed hydrogels with photoactivity were transformed either into a ‘hydrophobic hydrogel’ or pore-patched materials via secondary network introduction, where both processes were accomplished via visible light. Since g-C3N4 is an organic semiconductor exhibiting sufficient charge separation under visible light illumination, a novel method for the oxidative photopolymerization of EDOT was successfully accomplished. As a result of the absence of dissolved anions during polymerization, so-formed neutral PEDOT is a highly viscous liquid that can be processed and post-doped easily, and grants facile coating processes

Multimodal Imaging Characteristics of Quiescent Type 1 Neovascularization in Best Vitelliform Macular Dystrophy

This case report of a 38-year-old man with bilateral Best vitelliform macular dystrophy (BVMD) presents bilateral quiescent type 1 neovascularizations (NV) detected by optical coherence angiography (OCTA) and their multimodal imaging characteristics. It was emphasized that this kind of quiescent and asymptomatic NV may be present in nearly every stage of BVMD and it was concluded that OCTA is a noninvasive, easy, and rapid method that is superior to other imaging methods in detecting them

Impact of prolonged face mask wearing on tear break-up time and dry eye symptoms in health care professionals

Purpose To evaluate the impact of prolonged surgical face mask wearing on dry eye symptoms and tear film break-up time (T-BUT) in health care professionals. Materials and methods A total of 33 health care professionals were included in the present cross sectional prospective study. In addition to a complete ophthalmological examination T-BUT measurements were performed twice for all participants in the morning (8 am) and in the afternoon (5 pm). The subjects also filled-in the ocular surface disease index (OSDI) questionnaire twice, before and after wearing the face mask, on the same day. Results Sixty-six eyes of 33 participants (17 female and 16 male) were evaluated. The mean age was 33.6 +/- 7.55 (24-48) years and mean total duration with mask on between the two evaluations was 514 +/- 12.5 (495-526) minutes. The mean T-BUT was 9.3 +/- 1.0 (3-16) seconds at 8 am and 8.3 +/- 1.5 (3-14) seconds at 5 pm (p = 0.01). The mean OSDI score was 20.1 +/- 8.3 (0-68.75) at 8 am and 27.4 +/- 10.4 (0-81.25) at 5 pm (p 0.01). Conclusion Use of a surgical mask for the entire work-day was seen to worsen T-BUT and increase dry eye symptoms in healthy individuals. Ophthalmologists should be aware of the possibility of worsening of dry eye symptoms with the prolonged use of surgical face masks and consider modifications if necessary

Sheath-Preserving Complete Optic Nerve Avulsion Following Closed-Globe Injury: A Case Report

A 29-year-old man presented with a sudden loss of vision after a closed-globe injury. At presentation, he had no light perception in the right eye and the right pupil was dilated and nonreactive to light. On ophthalmological examination, the area of the optic nerve head was excavated, suggesting optic nerve avulsion. Magnetic resonance imaging scan showed optic nerve avulsion without rupture of the optic nerve sheath. Four months after the injury, the patient's visual acuity remained unchanged. Gliosis developed at the avulsion site. Closed-globe injuries may cause severe posterior injury even if there is no anterior damage in the eye. To prevent unnecessary treatment, trauma patients should be examined carefully appropriate imaging to confirm the diagnosis

Automatic Generation of Lightweight Controllability and Observability Structures for Analog Circuits

© 2015 IEEE. In this paper a method is presented to address the automatic testing of analog ICs. Based on Design-for-Testability building blocks offering extra controllability and extra observability, a test infrastructure is generated for a targeted circuit. The selection of the extra blocks and their insertion into the circuit is done automaticaly by a proposed optimization algorithm. Adopting a defect-oriented methodology, this algorithm maximizes the fault coverage and minimizes the silicon area overhead. The proposed method is applied to an industrial circuit to generate an optimal test infrastructure combining controllability and observability. The case study shows that, with a silicon area overhead of less than 10%, a fault coverage of 91% can be reached.status: publishe

Design and test of analog circuits towards sub-ppm level

© 2014 IEEE. Electronics are increasingly being embedded in a growing number of applications in our daily life. This demands strong reliability and robustness of those electronic systems. The IC manufacturing process not being perfect, however, inevitably results in some fabricated parts having defects. Test methods must detect such faulty ICs before shipment. While the fault coverage of testing for digital integrated circuits in industry today already reaches the sub-ppm level, this is not yet the case for analog integrated circuits or the analog part in mixed-signal ICs. This invited talk will review some techniques that are being explored in industrial practice to aim for sub-ppm-level coverage for the analog and mixed-signal circuits as well. This will be illustrated with some practical examples from automotive IC designs.status: publishe

Retinal detachment in a child with Frank-ter Haar syndrome

Background To present a rare case of ocular involvement in a child with Frank-ter Haar syndrome (FTHS) presenting retinal detachment. Materials and Methods Detailed ophthalmological evaluation including examination under general anesthesia, ocular ultrasound, and visual evoked potential testing was completed. Photographic documentation of the physical findings was obtained. Results A 3-year-old female patient with FTHS was referred to evaluate for possible ophthalmic involvement. The patient presented with the classical dysmorphic abnormalities of the syndrome. Ophthalmologic evaluation revealed a high, against-the-rule corneal astigmatism in the right eye. In the left eye, the red reflex was absent with a suspicious membrane behind the lens, and a sensory exotropia was present. Ultrasonography confirmed retinal detachment with no history of previous trauma. Due to poor visual evoked potentials, no surgery was planned. Astigmatic refractive error was corrected with routine follow-up. Conclusions FTHS is associated with multiple ocular involvement such as megalocornea, congenital glaucoma, or colobomas. This case report is the first to describe a high, against-the-rule astigmatism and retinal detachment in a female child with FTHS and demonstrates that an early and detailed ophthalmological examination is essential for these patients

Subgroups and Features of Poor Responders to Anti-Vascular Endothelial Growth Factor Treatment in Eyes with Neovascular Age-Related Macular Degeneration

WOS: 000585785600006Objectives: This study aimed to determine the incidence of poor response to intravitreal (IV) anti-VEGF treatment in neovascular age-related macular degeneration (nvAMD) and to define subgroups of poor responders. Materials and Methods: A total of 235 treatment-naive eyes of 202 patients completed this prospective study. Patients younger than 50 years of age and those with a contraindication for anti-VEGF therapy were excluded. All eyes were treated with IV ranibizumab. Poor response was defined as recurrence, persistence, or worsening despite treatment. Poor responders were classified into subgroups based on progression patterns. Results: of the 235 eyes, 78 (33.2%) showed poor response. Pigment epithelial detachment (PED) and occult choroidal neovascularization (CNV) were more common among poor responders (p<0.001) and 5 subgroups were identified. Conclusion: Poor response to anti-VEGF treatment is not uncommon and occult CNV and PED are frequently seen in these eyes. Various subgroups can be defined based on clinical features

Automatic test signal generation for mixed-signal integrated circuits using circuit partitioning and interval analysis

© 2016 IEEE. A method is presented to address the automatic generation of test signals for analog and mixed-signal integrated circuits. No restriction on the number of inputs or the nonlin-earity of the circuit are made. The circuit under consideration is first decomposed into a set of sub-circuits, called blocks, in order to break down the complexity of the problem. The effect of a targeted fault is then automatically analyzed at the transistor level in a defect-oriented context. From this analysis, the fault sensitization conditions are extracted and then backtraced towards the primary inputs and outputs of the circuit using an algorithm based on the interval analysis theory. The underlying algorithms supporting the automation of the whole procedure are illustrated for basic circuits. Finally, in order to demonstrate the method, an industrial circuit is used as case study. It is shown that test signals can be generated in order to achieve a fault coverage of 98%.status: publishe