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We report on a complete roll-to-roll (R2R) processed rigid-to-flex interposer using poly(3,4-ethylenedioxythiophene) : poly(styrenesulfonate) (PEDOT:PSS) doped with ethylene glycol (EG), spray coated onto a plastic polyethylene naphtalate (PEN) substrate with another single-sided adhesive PEN foil acting as a contact stencil mask for the interposer structures. A 355 nm solidstate R2R integrated laser,...
Contact-mode point spectroscopy and tapping-mode imaging atomic force microscopy (AFM) techniques were used to measure the Young's Modulus and tip-surface energy dissipation of amorphous chalcogenide thin films. As20Se80 thin film was prepared by thermal evaporation on glass substrates, and a He-Ne laser (633 nm) was used to prepare a holographic grating on the thin film. The results from both AFM...
The goal of this study is to investigate experimentally the thermal performance of an electronics cooling system which is available in the market. Selected system is a water block used for liquid cooling of a central processing unit (CPU) of a computer. A suitable heater (resistance wire) is fabricated for producing heat similar to CPU. System is instrumented with K-type thermocouples for the temperature...
At high power component packages having high area contact surfaces, voiding commonly appear, especially using insulated metal substrate (IMS) printed circuit boards (PCBs). Due to financial aspects, vacuum soldering is desired to be avoided. Vapour phase soldering (VPS) is an adequate technology for these kind of high thermal capacity circuits. The aim of the experiments was to reveal some of the...
The evolution of electronics to higher and higher power levels have determined an increased interest for thermal management techniques. In this sense, the quantitative determination of thermophysical parameters for materials used in electronic packaging materials becomes very important. We present in the paper a method to determine thermal diffusivity (a) of materials used as substrates, using IR...
Properties of polypropylene film capacitors, which are usually used in power electronics equipment, were examined after two-level process of electrical loading. Capacitors with the value of 10 nF and nominal voltage 630 V DC, 300 V AC, were loaded by the AC voltage with the frequency of 50 Hz in following steps: the voltage 450 V was applied for 30 min at first and consequently the voltage 500 V for...
Capacitors made of metalized polypropylene film are components with high quality and stability. Electrical ageing of these capacitors causes changes in quality of thin film metal electrodes dominantly; changes caused in quality of PP film are low. Method of measurement of current-voltage characteristic nonlinearity was chosen for evaluation of changes caused by electrical ageing of the capacitors...
Taking into account the real working temperatures from different zones and daily requirement of reduction of production costs, into automotive electronics production the trend is the one towards low melting point alloys that will enable energy savings and cost reductions during the manufacturing processes. In the paper, the mechanical strength of solder joints and samples having the same transversal...
The paper presents experimental results about Vapour Phase Soldering on flexible printed circuit boards, where the standard Surface Mounted Technology process was used for investigation. Test boards were prepared from FR4 type Printed Circuit Boards and single-sided flexible polyimide substrates. Lead-free SAC305 paste and different chip size surface mounted resistors were used for the test assembly...
For transfemoral amputation the prosthetic knee joint is most critical component among all the modules of the prosthesis. This is because knee has to provide complete stability to the body whether the person is walking, standing or performing any other knee related movement. Even during the normal gait cycle it has to perform angular flexion and extension in swing phase and undergoes full extension...
Nowadays, stencil printing process has become one of the most crucial steps in the continuously developing reflow soldering technology. In this research, the process of stencil printing was modelled with Finite Volume Method. The geometrical model consists of the squeegee with attack angle of 60°, the stencil and the solder paste as the domain of interest. During the modelling, the flow field inside...
This contribution proposes an improvement in the operation mode of Reflow Soldering Machine (RSM) for electronic board production, through the introduction of advanced control procedures for resistive heating elements. This method consists in the powering of resistors with a repetition rate controlled via a sigma-delta converter. The method's performances have been tested on a functional laboratory...
The necessity of having instruments for analyzing the quality of signal received by the reader from the transponder is more and more important in order to evaluate the performance parameters of RFID systems. In this paper we review the existing test procedures and transponder simulators that proved their utility in the development of SLRM1000 RFID system. We propose a new measurement device and procedure...
The paper presents a new version of the ROVIBAT (ROmanian VIrtual BAT) sonar head, based on airborne transducer module (ATM) with five discrete frequencies (40, 125, 200, 228 and 300 kHz). The sonar head is used for navigation of the robots and for ultrasonic image generation of the explored environment. The previous versions of the ROVIBAT heads, i.e. 00 to 04, have used a single working frequency...
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