Studies of the self-organized growth of nanoporous anodic aluminum oxide (AAO) films and anodization parameters have been the subject of decades of research and various theories. At the same time, temperature, being one of the most important parameters in anodizing treatments of aluminum, has been investigated only as a function of electrolyte temperature. This paper presents the results of studying the growth kinetics and morphology of AAO formed by anodization processes in 1 M H2SO4 at different anode temperatures. The activation energy of ionic conductivity for AAO determined in this study was 0.41 eV for sulfuric acid, which was greater than the activation energy of 0.34 eV for oxalic acid. The effect of anode temperature on the pore diameter (dpore) and the interpore distance (Dinter) was studied. It was demonstrated that in the temperature range from 10 to 40 °C, the dpore and Dinter did not change with the anode temperature, with values equal to 12.5 ± 0.1 nm and 52.5 ± 0.2 nm, respectively. However, when the anode (aluminum) temperature was increased to 60 °C, the dpore increased to 16 nm. The results obtained show that by increasing the temperature of the anode from 20 to 40 °C, it is possible to increase the ionic conductivity of AAO and thus achieve a greater than threefold increase in the the rate of AAO growth, without altering the porous morphology of the anodic films.

The article describes the study and the results of soldering with mixed two solder pastes - standard and low temperature in a combined footprint. The combined footprint was made by jet printer with a SAC305 and 58Bi42Sn pastes. The experiments were carried out with a different ratio between the standard and low-temperature pastes. It was measured whether changing the amount of bismuth in the solder paste changed the amount of voids in the component solders. Standard electronic components were examined and analyzed to obtain an objective statistical analysis.

The article describes the mixing of two solder pastes in a combined footprint - standard SAC305 and low temperature 58Bi42Sn. The combined footprint was carried out with a jet printer. The experiments were performed with a different ratio between standard and low temperature pastes. It was measured whether changing the amount of bismuth in the solder paste changed the breaking strength of the solders. A large number of electronic components are examined and analyzed to obtain an objective statistical analysis.

The article describes the study of the strength of solders in LGA (Land grid array) assembly. The influence of the design of the pads of the boards on the strength of the solders is considered. The breaking force measurement was performed with a specialized intelligent measurement system. Statistical methods were used to analyze the breaking force of solders. Best design conclusions regarding solder strength are drawn and future research to obtain stable and strong solders is suggested.

The results of determining the maximum breaking force that the connection between the printer head and the flexible board for transmitting electrical signals must withstand are presented. To stabilize the tensile strength of solders, in addition to soldering, additional stabilization of the solders with a coating with specialized glue was used. The tensile strength was measured with an intelligent measuring system in different variants of soldering and protection with glue. An analysis and evaluation of the results was performed through statistics.

The article presents the first results obtained from modified SMT (surface mount technology) assemblies with the application of PiP (Pin in Paste). The modification consists of the use of a combined footprint, consisting of two types of solder pastes (standard and low temperature) in one footprint. It can be applied using screen printing and jet printing. The aim is to use the entire amount of applied solder paste in the area of the pads and holes when over printing is used (applying paste on the solder mask) and to improve the conditions for obtaining quality assembly. The experiments were performed using a printer and a two-head jet printer. Deep machine learning has been applied in the preparation of the jet printer for the realization of the combined footprint. Ceramic and FR4 materials as well as real PCBs were used for the substrates. The obtained results are presented using statistics. They confirm the expectations - use of all solder material in the solder, lack of balls of solder material, non-eutectic melting of the solder material and lack of the tombstone effect. The obtained positive results give grounds for future in-depth study and development of the combined footprint, as well as for its industrialization.

The aluminium oxide obtained by anodization in acidic solutions has a highly ordered nanoporous structure consisting of straight parallel pores. The oxide layer has good electrical insulating properties on planar surfaces. However, the electrochemical formation of nanoporous film on convex surface induces effects such as crack formation and deterioration of the insulating properties. The present work is focused on investigating the conditions of growth of a thick oxide layer on aluminium wires with a diameter of 0.2 mm to 0.5 mm. In order to prevent cracking, the oxide growth was carried out by reducing the anodization voltage according to a mathematical model in view of obtaining conical pores. In this study, the minimum thickness at which a crack-free oxide layer grows was determined.

On the basis of the standard for testing in surface mounting, an area of critical deformation during the assembly of elements has been determined. A methodology for testing and determining the deformation was chosen, as well as tools for conducting experimental measurements. The results of the practical measurements of the deformations after soldering are presented. A conclusion is made on the basis of the obtained results regarding the admissibility of the process according to the standard.

The present paper presents the results of expanding the capabilities of the T-3002-PRO die bonder machine for testing solders in surface mounting. Using a modified tool to the working head and an additional tool on the working table it is possible to test the mechanical parameters of solders. It is possible to compare the hardness of different solders at different temperatures. A methodology for testing the tensile bond strength of mounted elements is also applied. The experimental results from the use of advanced features are presented.

Using the IPC / JEDEC-9704 and KEMET-MLCC (Multilayer Ceramic Chip Capacitors) Fex Failure Rate standards is a defined area of critical deformation in parametric testing of circuit boards. An intelligent measuring system was used to measure and determine the deformation, as well as a methodology for conducting experimental measurements. The results of practical studies of deformations in parametric testing of electronic modules on a panel for a specific automotive product are presented. A conclusion is made using the obtained results with conclusions about the acceptability of the process according to the standard and analysis of the transients in parametric testing.

The modes of synthesis of TiO2 films with semiconducting properties by the method of electrochemical oxidation of Ti are proposed for use as an electronic transport layer of perovskite solar cells. To anodize the titanium film, the electrolyte based on a mixture of a 2 % aqueous solution of oxalic acid and a 1 % aqueous solution of sulfamic acids was used. The results obtained showed that Al and Ni have injection contacts to the anodic TiO2 films. Nanoscale titanium oxide films have low resistivity and rectilinear and symmetric I - V characteristic branches. Annealing of titanium oxide films leads to a significant decrease in the resistivity.

Based on the standard for testing in surface mounting, an area of critical deformation is determined when mounting electronic modules in a housing (box). A methodology for testing and determining the deformation has been chosen, as well as tools for conducting experimental measurements. The results of practical measurements of deformations during assembly of electronic modules in a housing are pre...

By using an intelligent measuring system, the necessary preparation and measurement of the deformation of the PCB during the separation of the module (board with mounted electronic components) from the panel was performed. An area of critical deformation is defined based on the standards for testing in surface mounting. The results of practical measurements of deformations after separation of modules from panels are presented. A conclusion is made on the basis of the obtained results with conclusions regarding the admissibility of the process according to the standard.

The paper presents a noble-metal-free procedure for selective electroless deposition of copper patterns on a porous anodic alumina substrate. The substrate was functionalized with titanium dioxide capping layer via sol-gel dip-coating to improve its chemical stability in an alkaline copper plating electrolyte (pH>13). The photocatalytic activity of the titanium dioxide allows for selective deposition of copper seeds by UV lithography. The seed layer can then develop into a conductive pattern inside the same plating electrolyte. The work studies the effects of UV-irradiation and electroless deposition duration on the sheet resistance and wettability of the copper surface by three types of solder pastes.

In this paper, a simple, compact, and low-cost system for utilization of the thermal energy of the sun was designed and realized. The system is intended as a backup power supply of solar compact energy harvester and can serve also as a power supply for cooling the solar panel with thermoelectric cooler. For the system implementation, it was used specialized integrated circuit for power processing of DC small voltages with boost convertor LTC3107. The micropower processing device can charge a battery and backup capacitor extending the battery’s supply life when large periods of discontinuous input thermal energy exist. A printed circuit board (PCB) layout was used for photomask production and the system was fabricated by conventional PCB technology including photolithographic patterning of the printed wires. The system was tested with a Peltier element as a thermoelectric generator and it was found that it works stably in the temperature range 4 °C-46.6 °C, producing maximal output voltage of 2.53 V and storage capacitor voltage 1.78 V from a single thermoelectric convertor. The paper represents a synergistic connection between renewable energy processing, electronics, and microelectronic technology.

With an intelligent measuring system, the PCBA (Printed circuit board assembly) deformation was prepared and measured during a functional test of a product. An area of critical deformation is defined based on the standards for testing in surface mounting. The used intelligent measuring system and its setting are described. The results of practical measurements of deformations during functional testing of a specific product are presented. A conclusion is made on the basis of the obtained results with conclusions regarding the admissibility of the process according to the standard.

ZnO-Ga2O3 composite oxide films were RF sputtered and studied how the optical and electrical film properties are affected by the sputtering conditions and film thickness. The aim was to achieve low resistivity and at the same time, high transparency for the visible and short wavelength infrared (SWIR) electromagnetic range for the needs of simple, transparent and indium-free electrodes. A comparison was made with pristine ZnO films. We found that plasma voltage, respectively plasma power plays a crucial role in deter-mining the optoelectronic properties of the deposited films for the fabrication of combined photodetec-tors. The effective surface roughness of the ZnO-Ga2O3 films varied between12.9 nm and 16.7 nm when plasma power density varied between 35 and 54 W/cm(2), respectively. The increase of the sputtering power narrowed the transmission band to the longer wavelength from the visible spectrum. The transparency in the SWIR range varied between 83 and 96% and decreased with the plasma power increase, while the corresponding transparency in the visible range varied between 60 and 82%. The sheet resistance for the films under the best parameters demonstrating the highest transmission in both electro-magnetic ranges showed relatively low sheet resistance of 48 X/sq. The potential application of the prepared films is for VIS-IR detectors used in robotics for spatial information gain, gaming and virtual reality and autonomous car navigation, where the day and the night visions are equally important. (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conferences & Exhibition on Nanotechnologies, Organic Electronics & Nanomedicine - NANOTEXNOLOGY 2020.

The paper examines the possibility of obtaining topological structures from thick anodic alumina using a dry photoresist mask. A hypothesis for the oxide distribution under the photoresist is proposed and the model is compared to the experimental results using pillar and hole patterning. It is shown that the shape of the pattern curvature on growing anodic oxide has a significant effect on the stability of the photoresist.

Based on the flow chart for the production of electronic modules, the most frequently used operations are determined and the preparation, measurement and analysis of the stress of the components mounted on a specific board are made. After comparing the results in statics (maximum stress), dynamics (background stress and its development over time) and during (the time during which they are subjected to stress), conclusions are made about the most dangerous operations for damage to components of applied mechanical stress. In the conclusion the admissibility of the obtained deformations and the risk of using the described processes are assessed.

The report presents approach to reduce PCB distortion after heat treatment for soldering using a reflow process. The influence of the temperature profile at different heating of the lower side of the board has been studied and an optimal one has been established, in which the distortion of the boards is minimal and there is no danger of creating defects on the lower side. Conclusions are made when this approach can be used and how a secure temperature profile can be achieved for minimal board distortion after soldering with a reflow process.