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The paper presented is dedicated to the development and application of sensors and microsystems for evaluating various parameters of rolling stock in motion. The intended purpose of such a system, comprising of the described sensors and microsystems and also known as Wayside Monitoring System for Rolling Stock in Motion, is to identify the current overall condition of the railway vehicles, including...
The complete SMD-mounting process is a complex superposition of a lot of influences. There are general material (SMD-components, printed boards, solder paste, printing stencil), geometrical (layout) and process (solder paste printer, assembling equipment and their setup) influences. The main goal is the maximization of the process capabilities of the analyzed process. The superposition cannot be described...
In this paper, the effect of reflow cooling rate on the thermomechanical properties of a traditional SAC (Sn96.5/Ag3/Cu0.5) and of a micro-alloyed SAC (mSAC) solder (Sn98.9/Ag0.3/Cu0.7/Bi0.1/Sb0.01) was investigated. An FR4 based testboard was designed for the investigation; and preformed solder balls (0 600 μm) were soldered onto it with different cooling rates (1, 1.8, 2.8 K/s). After the soldering,...
One of the most favour components, which are mounted on the printed circuit board (PCB), is Ball Grid Array (BGA) due to higher integration. On the other hand BGAs are components which are the most problematic from point of solder interconnection reliability. The aim of this work was to make experimental study of the influence of the temperature profile on the BGA soldering during its reworks on electronic...
Solder is usually an alloy of two and more metals. Very often is used tin, lead, copper, silver, bismuth, nickel, etc. for its production. If the alloy is exposed to a sufficiently high temperature, it is induced phase change from solid to liquid phase for it. Phase is changed again from liquid to solid during cooling substance. At this point, the substance generates a latent heat that is manifests...
The goal of this paper is to present the method for automatic detection and location of power chip, which is soldered on DBC substrate, and voids in die attach solder joint. The method of chip location is provided by two dimension correlation applied on X-Ray images. When chip location is detected, voids in solder joints can be detected. It is very important to make such analysis, because during soldering...
The paper presents a technique used for the detection of the eye pupil center coordinates by using the least squares approach. The algorithm realizes the fitting of the ellipse to a group of input data points provided by the eye image collected using a video camera in infrared illumination. The method can be used in the area of assistive technology to implement an eye tracking system used to communicate...
The objective of this paper is to investigate a new design of an inductive sensor, and its application for measuring tangential displacement. The sensor consists of one stationary inductor and a movable ferrite plate relative to the inductor. Tangential displacement can be measured as a change in the overlapping area between the inductor and the ferrite plate, while their normal distance is constant...
In this paper are presented the results regarding the implementation and testing of a novel type of remote control based on the data transmission facilities offered by the GSM network infrastructure and the processing power achieved by new generation of microcontrollers. The system is intended to be used in the development of complex distributed control applications that are specific to various automated...
The presented article introduces a system for resin curing monitoring. The system is based on a combined sensor built on a ceramic substrate containing a heating element for independent surface heating, interdigital electrodes, and a Pt1000 thermistor for precise temperature measurements. The idea of the simple resin curing monitoring device is based on a small amount of tested resin being applied...
This article presents a “smart sound sensor” solution. More specifically it is a system on a chip capable of extracting sound patterns from an input signal captured by a microphone, patterns that correspond to certain musical instruments. The aim is to identify sounds like: voices, ambient sounds or musical sounds. Such applications generally involve the presence of a computer that analyzes offline...
PiP (Pin in Paste) is a technology for soldering with the least expenses and high quality because it is carried out fast (in one step for all components) and without human intervention. In the report it is shown the influence of geometry of the laid paste on the quality of soldering. It is examined in what geometry and in what ways of laying a reliable and repeated soldering can be achieved. There...
Random Number Generators are widely used in cryptographic applications (symmetric and asymmetric encryption, digital certificate generation, etc.) and other related areas. True Random Number Generators (TRNG) are based on physical non-deterministic phenomenon. Most of these generators are based on a large number of interconnected high frequency ring oscillators (RO), which are most commonly implemented...
The precise experimental determination of material properties is a prerequisite for FEM simulations estimating the reliability of electronic packages. Thereby, thin metallic wires are a major concern, because they often represent the weakest link of electronic devices. Therefore, we have performed tensile tests with copper wires with diameter of 25 μm. The microstructure of the wires was determined...
In this work, the capabilities of three (standard convection reflow, vacuum reflow and vapor phase reflow) soldering methods of surface mounting technology (SMT) are studied for high quality and reliability hidden solder joint formation. Comparative evaluations of the voids percent, which are formed in the hidden solder joints, were carried using X-ray inspection and testing the mechanical strength...
This paper deals with the implementation of thick film structures using screen and stencil printing for power electronics. The structures were realised with a sequential and a modified screen printing process and a polyimide stencil which are described in this paper. Using a sacrificial tape as a temporary stencil to obtain thicker conductors is investigated. All structures are compared in height,...
This paper describes the evaluation of screen printed materials fabricated with an additive manufacturing process for flexible biomedical applications. Five different conductive polymeric thick film pastes, printed on a polyimide substrate have been investigated. For the intended biocompatible applications, the cytotoxicity of the used materials was tested through adherent cell test. Furthermore,...
The following paper presents the development of an automated system for simultaneous recording of the human parameters, alongside highlighting the audio-visual stimuli — which are required in the analysis of the emotional perception to which the subject is tested. The automated system consists of two subsystems: the subsystem of acquisition/recording physiological parameters — audio-visual parameters...
This contribution introduces Failure Mode and Effect Analysis (FMEA) method applied to sputtering process. A model based paradigm is used for executing the FMEA method. The Authors employ this approach for increasing its efficiency and productivity. This work builds on the achievements resulting from the previous works concerning applying the Model Based FMEA method for the technological processes...
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