Failure analysis of electronic parts: Laboratory methods

Failure analysis test methods are presented for use in analyzing candidate electronic parts and in improving future design reliability. Each test is classified as nondestructive, semidestructive, or destructive. The effects upon applicable part types (i.e. integrated circuit, transitor) are discussed. Methodology is given for performing the following: immersion tests, radio graphic tests, dewpoint tests, gas ambient analysis, cross sectioning, and ultraviolet examination

Design and Test of a Gate Driver with Variable Drive and Self-Test Capability Implemented in a Silicon Carbide CMOS Process

Discrete silicon carbide (SiC) power devices have long demonstrated abilities that outpace those of standard silicon (Si) parts. The improved physical characteristics allow for faster switching, lower on-resistance, and temperature performance. The capabilities unleashed by these devices allow for higher efficiency switch-mode converters as well as the advance of power electronics into new high-temperature regimes previously unimaginable with silicon devices. While SiC power devices have reached a relative level of maturity, recent work has pushed the temperature boundaries of control electronics further with silicon carbide integrated circuits. The primary requirement to ensure rapid switching of power MOSFETs was a gate drive buffer capable of taking a control signal and driving the MOSFET gate with high current required. In this work, the first integrated SiC CMOS gate driver was developed in a 1.2 μm SiC CMOS process to drive a SiC power MOSFET. The driver was designed for close integration inside a power module and exposure to high temperatures. The drive strength of the gate driver was controllable to allow for managing power MOSFET switching speed and potential drain voltage overshoot. Output transistor layouts were optimized using custom Python software in conjunction with existing design tool resources. A wafer-level test system was developed to identify yield issues in the gate driver output transistors. This method allowed for qualitative and quantitative evaluation of transistor leakage while the system was under probe. Wafer-level testing and results are presented. The gate driver was tested under high temperature operation up to 530 degrees celsius. An integrated module was built and tested to illustrate the capability of the gate driver to control a power MOSFET under load. The adjustable drive strength feature was successfully demonstrated

Carbonaceous materials for their use as aircraft lightning strike protection

The main motivation behind this work, was to substitute the current technology used as lightning strike protection in the aircraft industry. This protection is composed of metallic meshes of foils, normally bronze, copper, and in some exceptional cases, for example in some fairings, aluminum in which cases, Glass Fiber Reinforced Polymer (GFRP) material will be added to avoid corrosion that direct contact between the Carbon Fiber (from the structural Carbon Fiber Reinforced Polymer material (CFRP)) and the Al might cause [1]. The bronze mesh adapts better to parts with complex geometries and is cheaper than cooper materials, however, its electrical conductivity is lower than the ones exhibited by copper meshes or foils. For those areas that need, not only Lightning Strike Protection (LSP), but also electromagnetic shielding, copper mesh or foils will be used such as Expanded Copper Foils (ECF), which is an epoxy pre-impregnated expanded copper foil that allows automated placement on the CFRP part.Programa de Doctorado en Ciencia e Ingeniería de Materiales por la Universidad Carlos III de MadridPresidente: Mauricio Terrones - Secretario: Francisco Javier Velasco Lopez - Vocal: José Sánchez Góme

Process techniques study of integrated circuits Final scientific report

Surface impurity and structural defect analysis on thermally grown silicon oxide integrated circui

A 5 meter range non-planar CMUT array for Automotive Collision Avoidance

A discretized hyperbolic paraboloid geometry capacitive micromachined ultrasonic transducer (CMUT) array has been designed and fabricated for automotive collision avoidance. The array is designed to operate at 40 kHz, beamwidth of 40° with a maximum sidelobe intensity of -10dB. An SOI based fabrication technology has been used for the 5x5 array with 5 sensing surfaces along each x and y axis and 7 elevation levels. An assembly and packaging technique has been developed to realize the non-planar geometry in a PGA-68 package. A highly accurate mathematical method has been presented for analytical characterization of capacitive micromachined ultrasonic transducers (CMUTs) built with square diaphragms. The method uses a new two-dimensional polynomial function to more accurately predict the deflection curve of a multilayer square diaphragm subject to both mechanical and electrostatic pressure and a new capacitance model that takes into account the contribution of the fringing field capacitances

Development of a 1D phased ultrasonic array for intravascular sonoporation

Error on title page – year of award is 2021.Sonoporation represents a promising approach to increase targeted drug delivery efficiency by facilitating transport of therapeutic agents to the target tissue with the use of ultrasound. However, most of the current research in sonoporation is performed with external ultrasonic transducers, which hinders the applicability of the therapeutic procedure for treatment of conditions situated deeper into the patient’s body, such as liver or intestinal tumours. This Thesis presents the development process of a miniature-sized 1-3 connectivity piezocomposite 1D phased array for intracorporeal sonoporation. The device was to be incorporated into a capsule or catheter and hence the primary design constraint was the reduced size of the piezoelectric element, which was limited to 2.5 mm in width and 12 mm in length. To meet the needs of the intended application, resonance frequencies of 1.5 MHz and 3.0 MHz were considered. A simulation framework was developed for optimization of the miniature array in relation to the peak negative pressure attained at the focus to mitigate the low power output associated with the limited device dimensions. This was implemented through a multiparametric sweep of the 1-3 piezocomposite geometry-related parameters. Devices made with PZT-5H and PMN-29%PT were evaluated. The optimization algorithm was used to determine specifications for phased array designs based on the two materials and the two resonance frequencies. The 1.5 MHz devices comprised 24 elements and the 3.0 MHz ones had 32 elements. The piezocomposites were manufactured using the dice and fill technique and electroded using a novel method of electrode deposition employing spin coating of Ag ink. Subsequently, the prototype devices were driven with a commercial array controller and characterized with a calibrated needle hydrophone in a scanning tank. Two simulation profiles based on finite element analysis and time extrapolation were developed to model the acoustic beams from the arrays, which were compared and calibrated with experimental data for focal distances between 5 mm and 10 mm and beam steering angles from 0° to 40°. The results showed that modelling could be employed reliably for therapeutic planning. Both the 1.5 MHz and the 3.0 MHz, PZT-5H arrays were tested in vitro and shown to induce and control sonoporation of a human epithelial colorectal adenocarcinoma cell layer. Finally, a 24 element, 1.5 MHz, PZT-5H array was implemented in a 40 mm long by 11 mm diameter tethered, biocompatible capsule intended for in vivo operation. The device was characterized in the scanning tank for steering angles in the range 0° to 56° and focal distances between 4.0 mm and 5.7 mm, and the measured beam profiles were correlated with the simulation framework. The capsule will be tested in future ex-vivo and in-vivo experiments on insulin absorption through porcine small bowel by means of sonoporation.Sonoporation represents a promising approach to increase targeted drug delivery efficiency by facilitating transport of therapeutic agents to the target tissue with the use of ultrasound. However, most of the current research in sonoporation is performed with external ultrasonic transducers, which hinders the applicability of the therapeutic procedure for treatment of conditions situated deeper into the patient’s body, such as liver or intestinal tumours. This Thesis presents the development process of a miniature-sized 1-3 connectivity piezocomposite 1D phased array for intracorporeal sonoporation. The device was to be incorporated into a capsule or catheter and hence the primary design constraint was the reduced size of the piezoelectric element, which was limited to 2.5 mm in width and 12 mm in length. To meet the needs of the intended application, resonance frequencies of 1.5 MHz and 3.0 MHz were considered. A simulation framework was developed for optimization of the miniature array in relation to the peak negative pressure attained at the focus to mitigate the low power output associated with the limited device dimensions. This was implemented through a multiparametric sweep of the 1-3 piezocomposite geometry-related parameters. Devices made with PZT-5H and PMN-29%PT were evaluated. The optimization algorithm was used to determine specifications for phased array designs based on the two materials and the two resonance frequencies. The 1.5 MHz devices comprised 24 elements and the 3.0 MHz ones had 32 elements. The piezocomposites were manufactured using the dice and fill technique and electroded using a novel method of electrode deposition employing spin coating of Ag ink. Subsequently, the prototype devices were driven with a commercial array controller and characterized with a calibrated needle hydrophone in a scanning tank. Two simulation profiles based on finite element analysis and time extrapolation were developed to model the acoustic beams from the arrays, which were compared and calibrated with experimental data for focal distances between 5 mm and 10 mm and beam steering angles from 0° to 40°. The results showed that modelling could be employed reliably for therapeutic planning. Both the 1.5 MHz and the 3.0 MHz, PZT-5H arrays were tested in vitro and shown to induce and control sonoporation of a human epithelial colorectal adenocarcinoma cell layer. Finally, a 24 element, 1.5 MHz, PZT-5H array was implemented in a 40 mm long by 11 mm diameter tethered, biocompatible capsule intended for in vivo operation. The device was characterized in the scanning tank for steering angles in the range 0° to 56° and focal distances between 4.0 mm and 5.7 mm, and the measured beam profiles were correlated with the simulation framework. The capsule will be tested in future ex-vivo and in-vivo experiments on insulin absorption through porcine small bowel by means of sonoporation

Technical Design Report for the PANDA Micro Vertex Detector

This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined