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Gold nanoparticles - which are intended to be used as transducers in a localized surface plasmon resonance (LSPR) sensor - were prepared by thermally annealing various layers of gold thin films deposited on glass substrate. The size and distribution of nanoparticles were investigated by atomic force microscopy (AFM). The changes in the nanoparticle shape in function of the deposition and annealing...
Although only at the stage of proof of concept, a basic approach in Occam technology is: placement of components on a dielectric substrate, encapsulation, reversal of the substrate, drilling down to pins of components, creation of conductive traces, a.s.o. Since a reversed order of construction of a simple circuit is considered to be much cheaper in terms of required equipment, this paper presents...
The effect of viscosity change of solder pastes during stencil printing on the pressure distribution along the stencil line and on the results of numerical modelling is investigated. Rheological properties of Type 4 SAC305 (Sn96.5Ag3Cu0.5) solder paste were measured for several cycles in our previous work, to investigate the viscosity change of pastes during stencil printing. Parameters of the Cross...
Conductive adhesive joints were formed by adhesive assembly of resistors with “zero” resistance on Cu pads. Adhesive with bis-phenol epoxy matrix filled by silver flakes in concentration 75 % b.w. was used for experiments. The test samples were aged at the temperature of 125 °C and the relative humidity of 64 %, in an environment with 95 % relative humidity at the temperature of 24 °C and in an environment...
The maximum temperature of all parts of automotive electronics equipment is given by the location and can vary between 358 K and 478 K. RoHS EU Directive in the context of the manufacturing costs reduction, necessity led automotive industry to create new Low-Temperature Lead-Free (LTLF) solder pastes family. In the paper, the thermophysical properties of the alloys from ALPHA® CVP-520 (SnBiAg) and...
The purpose of this article is to present our experiments with Vapour Phase Soldering, where the temperature distribution and heat transfer mechanisms were investigated on four test-boards with different substrates. We developed a method to measure the temperature gradients on-board inside an experimental vapour phase soldering oven. VP soldering process is suitable for consistent and rapid heating...
The paper is focused on different types of tools for process improvement - the synergy effect of using different tools and approaches together to drive the process to non-defective and faster execution. The goal of optimization is to decrease the total time of assembly and number of failures on assembled PCBs and to increase quality and reliability of the boards. The methodology is based on following...
Actual paper describes two implementation methods of an elliptical low pass filter using copper disc sectors on a PCB substrate. The main idea was to replace the series resonant branches of the filter circuit with radial stubs, which have the same equivalent circuit at high frequencies. Different approaches of the shapes and placement of the radial stubs were made during the study. Substrate material...
The aim of this study is to build an active auto-zeroing circuit for the three omega thermal conductivity measurement method to overcome the disadvantage of the method. For this purpose an auto-zeroing algorithm is implemented which consists of two stages; simply reading the voltage drops on lower hand side resistances with high resolution and setting the resistance of the digital potentiometer to...
Almost every aspect of modern life benefits at some point from electronic devices. Most of them are digital, and the data they receive is digitally sampled from a sensor at some point. The Sampling Theorem stands at the core of every data acquisition system design. Recent research shows there are certain situations where information is lost, if a signal is sampled according to the Sampling Theorem...
With the increased availability of technology and with the ability to miniaturize the electronic circuitry, more and more devices for cheating in exams are built. A cheating device is a complex system which allows a secret communication between the user and another person. However, a certain part of transmission is not encrypted in any form, and can be intercepted in a certain range. In this paper...
This paper shows part of the investigations conducted regarding the use of 2-layer printed circuit boards for embedded systems based on devices (microcontrollers or field programmable gate arrays) in BGA (Ball Grid Array) packages. Usually, the technical literature [1] recommends for applications involving programmable devices in BGA packages the use of multi-layer boards (4, 6 or more layers), but...
A modern portable computer, netbook, smartphone or camera is powered by a smart battery. This is a device containing one or more Lithium cells, protection circuits and a power management circuit, interfaced by a two wire SMBus interface [1]. The need for higher efficiency and longer battery life has pushed the technology of the smart battery forward, for higher efficiency, smaller component count...
In this paper we propose an ROV system (remotely operated vehicle) equipped with sensors and camera to monitor the marine life and offer impact estimation for the placement of oilrigs in the Black Sea reservoir. The robot is equipped with a low resolution analogue camera for real time image used by the pilot of the ROV and a HD camera for video recording of the marine ecosystem; the sensors (IMU and...
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