Technical Library | 1999-05-07 08:57:51.0
As a first step towards a perceptual user interface, a computer vision color tracking algorithm is developed and applied towards tracking human faces. Computer vision algorithms that are intended to form part of a perceptual user interface must be fast and efficient. They must be able to track in real time yet not absorb a major share of computational resources: other tasks must be able to run while the visual interface is being used. The new algorithm developed here is based on a robust nonparametric technique for climbing density gradients to find the mode (peak) of probability distributions called the mean shift algorithm.
Technical Library | 2010-12-22 13:59:14.0
This paper discusses polymer based nanogels, nanofluids and nanopastes for thermal interface material (TIM) applications. Nanopaste and nanogel formulated using controlled-sized particles to fill small bond lines is highlighted.
Technical Library | 2020-11-10 15:43:25.0
Flexible hybrid electronics (FHE) interface rigid electronic components with flexible sensors, circuits, and substrates. This paper reports the reliability improvement of a FHE Human Performance Monitor (HPM), designed to monitor electrocardiography (ECG) signals.
Technical Library | 2016-05-12 16:29:40.0
Advances in miniaturized electronic devices have led to the evolution of microvias in high density interconnect (HDI) circuit boards from single-level to stacked structures that intersect multiple HDI layers. Stacked microvias are usually filled with electroplated copper. Challenges for fabricating reliable microvias include creating strong interface between the base of the microvia and the target pad, and generating no voids in the electrodeposited copper structures. Interface delamination is the most common microvia failure due to inferior quality of electroless copper, while microvia fatigue life can be reduced by over 90% as a result of large voids, according to the authors’ finite element analysis and fatigue life prediction. This paper addresses the influence of voids on reliability of microvias, as well as the interface delamination issue.
Technical Library | 2019-06-20 00:09:49.0
It is well known that during service the layer of Cu6Sn5 intermetallic at the interface between the solder and a Cu substrate grows but the usual concern has been that if this layer gets too thick it will be the brittleness of this intermetallic that will compromise the reliability of the joint, particularly in impact loading. There is another level of concern when the Cu-rich Cu3Sn phase starts to develop at the Cu6Sn5/Cu interface and an imbalance in the diffusion of atomic species, Sn and Cu, across that interface results in the formation at the Cu3Sn/Cu interface of Kirkendall voids, which can also compromise reliability in impact loading. However, when, as is the case in some microelectronics, the copper substrate is thin in relation to the volume of solder in the joint an overriding concern is that all of the Cu will be consumed by reaction with Sn to form these intermetallics.This paper reports an investigation into the kinetics of the growth of the interfacial intermetallic, and the consequent reduction in the thickness of the Cu substrate in solder joints made with three alloys, Sn-3.0Ag-0.5Cu, Sn-0.7Cu-0.05Ni and Sn-1.5Bi-0.7Cu-0.05Ni.
Technical Library | 2011-03-24 18:48:30.0
In this paper, a PCB layout technique is proposed to maintain ideal return paths for high-speed traces routing. Our goal is to implement and verify the digital LCD-TV in 2-layer PCB including the high-speed memory interfaces with less electromagnetic radi
Technical Library | 2020-06-10 01:42:55.0
Recent advancement of flexible wearable electronics allows significant enhancement of portable, continuous health monitoring and persistent human-machine interfaces. Enabled by flexible electronic systems, smart and connected bioelectronics are accelerating the integration of innovative information science and engineering strategies, ultimately driving the rapid transformation of healthcare and medicine. Recent progress in the development and engineering of soft materials has provided various opportunities to design different types of mechanically deformable systems towards smart and connected bioelectronics.
Technical Library | 2017-06-15 00:44:19.0
Ceramics packages are being used in the electronics industry to operate the devices in harsh environments. In this paper we report a study on acoustic imaging technology for nondestructively inspecting underfill layers connecting organic interposers sandwiched between two ceramics substrates.First, we inspected the samples with transmission mode of scanning acoustic tomography (SAT) system, an inspection routine usually employed in assembly lines because of its simpler interpretation criteria: flawed region blocks the acoustic wave and appears darker. In this multilayer sample, this approach does not offer the crucial information at which layer of underfill has flaws. To resolve this issue, we use C-Mode Scanning in reflection mode to image layer by layer utilizing ultrasound frequencies from 15MHz to 120MHz. Although the sample is thick and contains at least 5 internal material interfaces, we are able to identify defective underfill layer interfaces.
Technical Library | 2001-04-24 10:41:53.0
Tau models describe the timing and functional information of component interfaces. Timing information specifies the delay in placing values on output signals and the timing constraints (set-up/hold, pulse-width) on input signals of a component. Functional information, through a finite state machine (FSM), specifies when output signal values change, when input signal values are latched, and how output values are determined as a function of input values.
Technical Library | 2009-12-09 19:28:28.0
A fundamental evaluation of a variety of approaches for designing a high-speed (10 Gb/s) serial differential electrical channel is examined. The application of the electrical interface has been simulated using HSpice software. It demonstrated how the signal quality could be affected by the use of microstrip versus stripline traces and their associated advantages and disadvantages is discussed. Example XFI channels were assembled from the simulation results to demonstrate viability of the application.
