Characterizing the conductivity of ICA joints by the mean intercept length of Ag flakes

2016 ◽  
Vol 28 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Balázs Illés ◽  
Olivér Krammer ◽  
Attila Géczy ◽  
Tamás Garami
Keyword(s):  
Image Processing ◽  
Printed Circuit Board ◽  
Quality Parameters ◽  
Circuit Board ◽  
Temperature Sensitive ◽  
Electrical Measurements ◽  
Content Type ◽  
Printed Circuit ◽  
The Mean ◽  
Mean Intercept Length

Purpose – The purpose of this paper is to present a novel and alternative method for the characterization of isotropic conductive adhesive (ICA) joints’ conductivity by the calculation of the mean intercept length of conductive flakes in the cured joint. ICAs are widely used in the field of hybrid electronics or special printed circuit board applications, such as temperature sensitive or flexible circuits. The main quality parameters of the ICA joints are the conductivity and the mechanical strength. Design/methodology/approach – For the experiments, one-component Ag-filled thermoset ICA paste was used on FR4 printed circuit test board to join zero-ohm resistors. Six different curing temperatures were applied: 120, 150, 175, 210, 230 and 250°C. The conductivity of the joints was measured in situ during the curing process. Micrographs were taken from the cross-sectioned joints, and the mean intercept length was calculated on them after image processing steps. Findings – Results of the measured conductivity and the mean intercept length were compared, and acceptable correlation was found for what can be used for characterizing the conductibility of ICA joints. Research limitations/implications – Investigating and characterizing the conductivity of ICA joints by an image processing method. Originality/value – The main advantage of this method compared to the electrical measurements is that the conductivity characterization is possible on any kind of component. Therefore, this method can be used in any appliances not only in test circuits.

Evaluation of new technologies and materials for printed circuit boards with improved heat dissipation properties

Circuit World ◽  
2016 ◽  
Vol 42 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Michal Baszynski ◽  
Edward Ramotowski ◽  
Dariusz Ostaszewski ◽  
Tomasz Klej ◽  
Mariusz Wojcik ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Printed Circuit Boards ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
New Technologies ◽  
Electronic Device ◽  
Circuit Board ◽  
New Materials ◽  
Content Type ◽  
Printed Circuit

Purpose – The purpose of this paper is to evaluate thermal properties of printed circuit board (PCB) made with use of new materials and technologies. Design/methodology/approach – Four PCBs with the same layout but made with use of different materials and technologies have been investigated using thermal camera to compare their thermal properties. Findings – The results show how important the thermal properties of PCBs are for providing effective heat dissipation, and how a simple alteration to the design can help to improve the thermal performance of electronic device. Proper layout, new materials and technologies of PCB manufacturing can significantly reduce the temperature of electronic components resulting in higher reliability of electronic and power electronic devices. Originality/value – This paper shows the advantages of new technologies and materials in PCB thermal management.

Robotic system design and development for automated dismantling of PCB waste

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ioan Doroftei ◽  
Daniel Chirita ◽  
Ciprian Stamate ◽  
Stelian Cazan ◽  
Carlos Pascal ◽  
...  
Keyword(s):  
Design Methodology ◽  
Printed Circuit Board ◽  
Vision System ◽  
Electronic Waste ◽  
Robotic System ◽  
Circuit Board ◽  
Short Introduction ◽  
Content Type ◽  
Printed Circuit ◽  
System A

Purpose The mass electronics sector is one of the most critical sources of waste, in terms of volume and content with dangerous effects on the environment. The purpose of this study is to provide an automated and accurate dismantling system that can improve the outcome of recycling. Design/methodology/approach Following a short introduction, the paper details the implementation layout and highlights the advantages of using a custom architecture for the automated dismantling of printed circuit board waste. Findings Currently, the amount of electronic waste is impressive while manual dismantling is a very common and non-efficient approach. Designing an automatic procedure that can be replicated, is one of the tasks for efficient electronic waste recovery. This paper proposes an automated dismantling system for the advanced recovery of particular waste materials from computer and telecommunications equipment. The automated dismantling architecture is built using a robotic system, a custom device and an eye-to-hand configuration for a stereo vision system. Originality/value The proposed approach is innovative because of its custom device design. The custom device is built using a programmable screwdriver combined with an innovative rotary dismantling tool. The dismantling torque can be tuned empirically.

Analysis of surface insulation resistance related failures in electronics by circuit simulation

Circuit World ◽  
2017 ◽  
Vol 43 (2) ◽  
pp. 45-55 ◽  
Author(s):  
Vadimas Verdingovas ◽  
Salil Joshy ◽  
Morten Stendahl Jellesen ◽  
Rajan Ambat
Keyword(s):  
Printed Circuit Board ◽  
Electronic Device ◽  
Early Stage ◽  
Circuit Simulation ◽  
Circuit Board ◽  
Insulation Resistance ◽  
Electronic Circuits ◽  
Content Type ◽  
Printed Circuit ◽  
Surface Insulation Resistance

Purpose The purpose of this study is to show that the humidity levels for surface insulation resistance (SIR)-related failures are dependent on the type of activators used in no-clean flux systems and to demonstrate the possibility of simulating the effects of humidity and contamination on printed circuit board components and sensitive parts if typical SIR data connected to a particular climatic condition are available. This is shown on representative components and typical circuits. Design/methodology/approach A range of SIR values obtained on SIR patterns with 1,476 squares was used as input data for the circuit analysis. The SIR data were compared to the surface resistance values observable on a real device printed circuit board assembly. SIR issues at the component and circuit levels were analysed on the basis of parasitic circuit effects owing to the formation of a water layer as an electrical conduction medium. Findings This paper provides a summary of the effects of contamination with various weak organic acids representing the active components in no-clean solder flux residue, and demonstrates the effect of humidity and contamination on the possible malfunctions and errors in electronic circuits. The effect of contamination and humidity is expressed as drift from the nominal resistance values of the resistors, self-discharge of the capacitors and the errors in the circuits due to parasitic leakage currents (reduction of SIR). Practical/implications The methodology of the analysis of the circuits using a range of empirical leakage resistance values combined with the knowledge of the humidity and contamination profile of the electronics can be used for the robust design of a device, which is also important for electronic products relying on low current consumption for long battery lifetime. Originality/value Examples provide a basic link between the combined effect of humidity and contamination and the performance of electronic circuits. The methodology shown provides the possibility of addressing the climatic reliability of an electronic device at the early stage of device design by using typical SIR data representing the possible climate exposure.

Study on fine lines and undercut suppression of printed circuit board prepared by electrolytic etching

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Denglin Fu ◽  
Yanan Wen ◽  
Jida Chen ◽  
Lansi Lu ◽  
Ting Yan ◽  
...  
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibitors ◽  
Printed Circuit Board ◽  
Copper Surface ◽  
Etching Process ◽  
Circuit Board ◽  
Content Type ◽  
Printed Circuit ◽  
Etching Method ◽  
Electrolytic Etching

Purpose The purpose of this paper is to study an electrolytic etching method to prepare fine lines on printed circuit board (PCB). And the influence of organics on the side corrosion protection of PCB fine lines during electrolytic etching is studied in detail. Design/methodology/approach In this paper, the etching factor of PCB fine lines produced by new method and the traditional method was analyzed by the metallographic microscope. In addition, field emission scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the inhibition of undercut of the four organometallic corrosion inhibitors with 2,5-dimercapto-1,3,4-thiadiazole, benzotriazole, l-phenylalanine and l-tryptophan in the electrolytic etching process. Findings The SEM results show that corrosion inhibitors can greatly inhibit undercut of PCB fine lines during electrolytic etching process. XPS results indicate that N and S atoms on corrosion inhibitors can form covalent bonds with copper during electrolytic etching process, which can be adsorbed on sidewall of PCB fine lines to form a dense protective film, thereby inhibiting undercut of PCB fine lines. Quantum chemical calculations show that four corrosion inhibitor molecules tend to be parallel to copper surface and adsorb on copper surface in an optimal form. COMSOL Multiphysics simulation revealed that there is a significant difference in the amount of corrosion inhibitor adsorbed on sidewall of the fine line and the etching area. Originality/value As a clean production technology, electrolytic etching method has a good development indicator for the production of high-quality fine lines in PCB industry in the future. And it is of great significance in saving resources and reducing environmental pollution.

Surface temperature of electronic assemblies equipped with tilted and low-powered QFN64 subjected to free convection

2017 ◽  
Vol 27 (6) ◽  
pp. 1304-1310 ◽  
Author(s):  
Abderrahmane Baïri ◽  
Clara Ortega Hermoso ◽  
David San Martén Ortega ◽  
Iken Baïri ◽  
Zsolt Peter
Keyword(s):  
Surface Temperature ◽  
Inclination Angle ◽  
Printed Circuit Board ◽  
Electronic Device ◽  
Thermal Design ◽  
Circuit Board ◽  
Content Type ◽  
Printed Circuit ◽  
Volume Method ◽  
Electronic Assemblies

Purpose This work deals with the case of the quad flat non-lead 64 (QFN64) electronic package generating a low power range ranging from 0.01 to 0.1W. It is installed on one side of a printed circuit board (PCB) that can be inclined relative to the horizontal plane with an angle varying between 0° and 90° (horizontal and vertical positions, respectively). The surface temperature of the electronic assembly is subjected to air natural convection. Design/methodology/approach Calculations are done by means of the finite volume method for many configurations obtained by varying the generated power and the inclination angle. Findings The distribution of the surface temperature is determined on all the assembly areas (QFN and PCB). The study shows that the thermal behaviour of the electronic device is influenced by the generated power and the inclination angle. The 3D numerical survey leads to correlations allowing calculation of the average surface temperature in any part of the assembly, according to the power generated by the QFN64 and the inclination angle. Originality/value The proposed accurate correlations are original and unpublished. They optimize the thermal design of the electronic QFN64 package, which is increasingly used in many engineering fields.

Investigations of temperature sensor embedded into PCB

2020 ◽  
Vol 37 (4) ◽  
pp. 199-204
Author(s):  
Kamil Janeczek ◽  
Aneta Araźna ◽  
Wojciech Stęplewski ◽  
Marek Kościelski ◽  
Krzysztof Lipiec ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Functional Properties ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Electronic Devices ◽  
Circuit Board ◽  
Temperature Sensitive ◽  
Content Type ◽  
Transponder Ic ◽  
Passive Sensor

Purpose The purpose of this study is to design and fabricate a simple passive sensor circuitry embedded into a printed circuit board (PCB) and then to examine its properties. Design/methodology/approach A passive sensor transponder integrated circuit (IC) working in the high frequency (HF) 13.56 MHz frequency band was selected for this study. A loop antenna was designed to make the reported sensor circuitry readable. Next, the sensor circuitry was fabricated and embedded into a PCB with the proposed technologies. Finally, properties of the embedded structures were examined as well-functional parameters of the sensor circuitries. Findings The described investigation results confirmed that the proposed technologies using an epoxy resin or standard materials used for PCB’s production allowed to successfully produce sensors embedded into PCBs. This technology did not have a negative significant impact either on quality of solder joints of the assembled transponder IC or on functional properties of the embedded sensor. Apart from the identification data, the reported sensor can provide information about a selected property of its environment, e.g. temperature when its internal temperature sensitive element is used or other factors with the use of external sensitive elements, such as humidity. Research limitations/implications It is planned to carry on the reported investigations to examine other types of sensor circuitries capable of indicating e.g. humidity level and to evaluate influence of the proposed technology on their functional properties. Practical implications The reported sensor circuitries can be successfully used in electronic industry in internet of things systems not only to identify monitored electronic devices, but also to control selected parameters of external environment. This creates opportunity to detect device malfunction by detecting local temperature growth or to analyze its environment, which might allow to predict failure of controlled products using radio waves. This advantage seems to be extremely beneficial for applications, such as space, aviation or military, in which embedded sensor systems may lead to enhancing reliability of electronic devices by reacting on occurred failures in a more efficient way. Originality/value This study demonstrates valuable information for engineers conducting research on sensor components embedded into PCBs. The reported technologies are quite simple and cost-effective because of the use of standard materials known for PCB’s production or an epoxy resin which could be treated as an additional encapsulant material enhancing mechanical properties of the embedded sensor transponder IC.

Influence of the area of a thermal pad on optical and thermal parameters of LED modules

Circuit World ◽  
2020 ◽  
Vol 46 (2) ◽  
pp. 65-70 ◽  
Author(s):  
Krzysztof Górecki ◽  
Przemysław Piotr Ptak
Keyword(s):  
Thermal Resistance ◽  
Power Density ◽  
Printed Circuit Board ◽  
Thermal Parameters ◽  
Circuit Board ◽  
Optical Parameters ◽  
Metal Core ◽  
Content Type ◽  
Printed Circuit

Purpose The purpose of this paper is to present and discuss the results of measurements illustrating influence of the area of a thermal pad and the kind of the used base on thermal and optical parameters of LED modules. Design/methodology/approach LED modules including six power LEDs are designed. In the layout of these modules, different areas of a thermal pad of each LED are used. These modules are made using the classical FR-4 base and metal core printed circuit board (MCPCB). Thermal and optical parameters of all the tested modules are measured using the method elaborated by the authors. Findings The obtained results of measurements prove that increasing the area of a thermal pad causes a decrease in thermal resistance of the tested LED modules and an increase in power density of the emitted light. The role of the area of a thermal pad is more important for the classical FR-4 base than for MCPCB. Research limitations/implications Investigations were performed for only two values of the area of thermal pads and selected values of LEDs forward current. Originality/value The presented results of investigations show how the used layout and type of the used base of these modules influence optical and thermal parameters of LED modules. Changing the base of a module can cause even a double decrease in thermal resistance and a double increase in power density of the emitted light.

PCB welding spot detection with image processing method based on automatic threshold image segmentation algorithm and mathematical morphology

Circuit World ◽  
2016 ◽  
Vol 42 (3) ◽  
pp. 97-103 ◽  
Author(s):  
Shi yuan Wang ◽  
Yang Zhao ◽  
Liuying Wen
Keyword(s):  
Image Processing ◽  
Printed Circuit Board ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Processing Method ◽  
Circuit Board ◽  
Content Type ◽  
Image Processing Method ◽  
Spot Detection ◽  
Welding Spot

Purpose To enhance the detection efficiency of printed circuit board (PCB) soldered dot, this study aims to detect PCB soldered dot with image processing method. Design/methodology/approach Through a series of image processing algorithms, threshold segmentation and feature extraction of the solder joint images were completed; then, sphericity was confirmed based on the area and perimeter, as well as the shape parameter and eccentricity ratio of the calculated region, paving the way for defect pattern recognition. Findings It proves that the method with high efficiency and precision can satisfy the requirements of PCB soldered dot detection. Originality/value This paper is original in presenting a method for PCB welding spot detection.

Studying heat transfer on inclined printed circuit boards during vapour phase soldering

2017 ◽  
Vol 29 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Attila Geczy ◽  
Daniel Nagy ◽  
Balazs Illes ◽  
Laszlo Fazekas ◽  
Oliver Krammer ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Vapour Phase ◽  
Circuit Board ◽  
Efficient Production ◽  
Content Type ◽  
Printed Circuit ◽  
Heat Transfer Efficiency ◽  
Uneven Heating

Purpose The paper aims to present an investigation of heating during vapour phase soldering (VPS) on inclined printed circuit board (PCB) substrates. The PCB is a horizontal rectangular plate from the aspect of filmwise condensation with a given inclination setting. Design/methodology/approach The paper focuses on the measurement of temperature distribution on the PCBs with a novel setup immersed in the saturated vapour space. The measuring instrumentation is optimized to avoid and minimize vapour perturbing effects. Findings The inhomogeneity of the heating is presented according to the lateral dimensions of the PCB. The inclination improves temperature uniformity, improves heat transfer efficiency; however, a minor misalignment may affect the flow and result in uneven heating. Practical implications The results can be implemented for practical improvements in industrial ovens with the use of intended inclination. The improvements may consequently point to more efficient production and better joint quality. Originality/value The novel method can be used for deeper investigation of inclination during and can be complemented with numerical calculations. The results highlight the importance of precise PCB holding instrumentation in VPS ovens.

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