Electrical characterization of thin film nanostructure templates

An improved apparatus for anodizing aluminum films on Si substrates is presented. In addition, an explanation is given for adapting the system to SiC and glass substrates. The system presented is optimized for throughput and safety to focus on volume production. MOS capacitors created with the system are analyzed with capacitance-voltage measurement techniques to provide insight into device operation. Ni is deposited into porous alumina templates to create Ni nanostructures

A switching ensemble approach for remaining useful life estimation of electrolytic capacitors

open4In this work, we consider the problem of predicting an equipment Remaining Useful Life (RUL), based on data from a fleet of similar components working under different operating conditions (Al-Dahidi et al. 2015).Al-Dahidi, S.; Di Maio, F.; Baraldi, P.; Zio, E.AL-DAHIDI, SAMEER MAHMOUD AHMED; DI MAIO, Francesco; Baraldi, Piero; Zio, Enric

Remaining useful life estimation in heterogeneous fleets working under variable operating conditions

The availability of condition monitoring data for large fleets of similar equipment motivates the development of data-driven prognostic approaches that capitalize on the information contained in such data to estimate equipment Remaining Useful Life (RUL). A main difficulty is that the fleet of equipment typically experiences different operating conditions, which influence both the condition monitoring data and the degradation processes that physically determine the RUL. We propose an approach for RUL estimation from heterogeneous fleet data based on three phases: firstly, the degradation levels (states) of an homogeneous discrete-time finite-state semi-markov model are identified by resorting to an unsupervised ensemble clustering approach. Then, the parameters of the discrete Weibull distributions describing the transitions among the states and their uncertainties are inferred by resorting to the Maximum Likelihood Estimation (MLE) method and to the Fisher Information Matrix (FIM), respectively. Finally, the inferred degradation model is used to estimate the RUL of fleet equipment by direct Monte Carlo (MC) simulation. The proposed approach is applied to two case studies regarding heterogeneous fleets of aluminium electrolytic capacitors and turbofan engines. Results show the effectiveness of the proposed approach in predicting the RUL and its superiority compared to a fuzzy similarity-based approach of literature

Improved Reference Infrared Spectrometer

Infrapunasäteily on sähkömagneettista säteilyä, jonka aallonpituus on 750 nn - 1 mm. Se on tärkeä työväline optisessa spektroskopiassa, vaikka onkin ihmissilmälle näkymätöntä. Optisella spektrometrillä tarkoitetaan laitetta, joka mittaa materiaalin emissio-, absorptio- tai fluoresenssispektriä. Tässä työssä uudistettiin Aalto-yliopiston Mittaustekniikan ryhmän referenssi-infrapunaspektrometriä. Laitetta käytetään ilmaisimen vasteen, aineen läpäisyn ja lähteen tehojakauman spektrisiin mittauksiin aallonpituusalueella 750 nm - 16 µm. Mittauslaitteisto automatisoitiin käyttäen LabVIEW-ohjelmistoa. Lisäksi kalibrointi- ja mittausmenetelmiä paranneltiin. Automatisoitu mittauslaitteisto soveltuu monipuolisesti erilaisiin mittausjärjestelyihin ja on aiempaa helpompi käyttää. Mittauksissa käytetään vaihelukittua vahvistinta, joka mahdollistaa hyvin heikkojen signaalien havaitsemisen suuren kohinasignaalin läsnäolosta huolimatta. Mitattavaa signaalia moduloidaan katkomalla valolähdettä referenssitaajuudella. Optisen menetelmän sijaan vaihelukitun vahvistimen lineaarisuusmittauksiin kehitettiin täysin sähköinen menetelmä, joka parantaa ulkoista tarkkuutta vertailumittauksissa. Lisäksi osana työtä suunniteltiin, rakennettiin ja karakterisoitiin esivahvistin valojohtaville ilmaisimille. Tavanomaisesta sovitetusta esivahvistimesta poiketen laitteen keskeiset parametrit ovat säädettäviä, joten sitä voidaan käyttää lukuisien eri ilmaisimien kanssa.Infrared radiation is electromagnetic radiation with a spectrum ranging from 750 nm to 1 mm in wavelength. It is invisible to the human eye, but has significance in optical spectroscopy. An optical spectrometer is a device that measures the emission, absorption, or fluorescence spectrum of a material. In this work, a reference infrared spectrometer facility at the Metrology Research Institute was upgraded. The spectrometer can be used to measure spectral responsivity of detectors, spectral transmittance of optical materials and spectral power distribution measurements of light sources in the wavelength range of 750 nm to 16 ?m. The measurement setup was improved for full automation using LabVIEW and the previous calibration and automation procedures were refined. Automated facility is versatile for different measurement setups and is easy to operate. Phase sensitive detection is utilized in the measurement setup by using a lock-in amplifier. It enables the detection of very small signals in the presence of overwhelming noise. Optical chopping is used to modulate the measurement signal at a known reference frequency. Typically the linearity of the measurement system is determined optically. Also in this work, a fully electronic method for linearity measurements of lock-in amplifiers was developed and tested. This method improves the accuracy in lock-in comparison measurements. In addition, a preamplifier for photoconductive detectors was constructed and characterized. The amplifier was designed so that it can be used with wide variety of detectors

Evaluación de los impactos en la calidad de la energía por la compensación de potencia reactiva con bancos de condensadores y D-STATCOM

This paper presents an assessment of capacitor banks and Distribution Static Compensator (D-STATCOM) with respect to their impact on energy quality. Tests were done with capacitor banks built with electrolytic capacitors commonly used in industrial applications and a D-STATCOM. Experimental tests were performed for power factor correction in order to reduce the reactive power demanded from the electrical grid for inductive-resistive loads. For comparative purposes, the control of the D-STATCOM was set to operate with similar compensation conditions to that of the capacitor banks. Results show that under the same test conditions capacitor banks produce higher Total Harmonic Distortion (THD) than D-STATCOM.Este artículo presenta una evaluación de los bancos de capacitores y el Compensador Estático de Distribución (D-STATCOM) con respecto a su impacto en la calidad de la energía. Las pruebas fueron hechas con bancos de capacitores construidos con capacitores electrolíticos comúnmente usados en aplicaciones industriales y un D-STATCOM. Las pruebas experimentales fueron realizadas para corrección del factor de potencia, con el fin de reducir la potencia reactiva demandada por la red eléctrica con cargas resistivo-inductivas. Por propósitos comparativos, el control del D-STATCOM se programó para operar en similares condiciones de compensación respecto al banco de capacitores. Los resultados muestran que, bajo las mismas condiciones de prueba, los bancos de capacitores producen mayor Distorsión Armónica Total que el D-STATCOM

Characterization of Polymer Hermetic Sealed Tantalum Capacitors Using Thin-film Devices

Polymer Hermetic Sealed (PHS) capacitors are advanced polymer capacitors with a hermetic seal enclosing the materials inside a metal enclosure. Their primary features include leakage current stability, high volumetric efficiency, and low weight compared to both wet and solid-state polymer tantalum capacitors. However, Life Tests performed on these capacitors have revealed a failure to withstand their rated voltage in a working temperature range over the long-term. There are also other interesting properties which have been observed such as Breakdown voltage (BDV) exceeding the Formation Voltage (Vf), anomalous transient currents, and a larger than expected capacitance dependence on temperature, C(T). A primary goal in this research is to understand whether the observed characteristics of PHS capacitors are a result of their complex structure or due more to the nature of interactions between the organic and inorganic material layers present. C(T) and BDV measurements were performed on thin-film MIS capacitors representing the material layers of PHS capacitors. Measurements were performed in the voltage range (0V-100V), a temperature range (-550C to 1250C), with varying frequency (20-10kHz), under both humid and dry conditions. Furthermore, one sample went through a curing process referred to as Heat Treatment , which is thought to improve device stability. Results from these measurements show that thin-film devices can be reasonable representatives of discrete PHS capacitors, and the properties observed in PHS capacitors are significantly dependent on the material layers in the capacitors. Thus, the thin-film MIS capacitor is shown to be a useful test structures for investigating physical phenomena observed in the more complex polymer Ta capacitor structure

Review of Health Prognostics and Condition Monitoring of Electronic Components

To meet the specifications of low cost, highly reliable electronic devices, fault diagnosis techniques play an essential role. It is vital to find flaws at an early stage in design, components, material, or manufacturing during the initial phase. This review paper attempts to summarize past development and recent advances in the areas about green manufacturing, maintenance, remaining useful life (RUL) prediction, and like. The current state of the art in reliability research for electronic components, mainly includes failure mechanisms, condition monitoring, and residual lifetime evaluation is explored. A critical analysis of reliability studies to identify their relative merits and usefulness of the outcome of these studies' vis-a-vis green manufacturing is presented. The wide array of statistical, empirical, and intelligent tools and techniques used in the literature are then identified and mapped. Finally, the findings are summarized, and the central research gap is highlighted