Influence of the soldering paste type on optical and thermal parameters of LED modules

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak ◽  
Barbara Dziurdzia
Keyword(s):  
Design Methodology ◽  
Printed Circuit Board ◽  
Electrical Energy ◽  
Thermal Parameters ◽  
Circuit Board ◽  
Metal Core ◽  
Content Type ◽  
Printed Circuit ◽  
Soldering Process ◽  
Practical Implications

Purpose This paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes. Design/methodology/approach The tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The results of measurements obtained for different modules are compared and discussed. Findings It was shown that the soldering process visibly influences the results of measurements of optical and thermal parameters of LED modules. For example, values of thermal resistance of these modules and the efficiency of conversion of electrical energy into light differ between each other even by 15%. Practical implications The obtained results of investigations can be usable for designers of the assembly process of power LED modules. Originality/value This paper shows the investigations results in the area of effective assembly of power LEDs to the metal core printed circuit board (MCPCB) using different soldering pastes (REL22, REL61, LMPA-Q6, OM-5100, OM-338-PT, M8, OM-340, CVP-390). It was shown that the best thermal and optical properties of these modules are obtained for the OM5100 paste by Alpha Assembly.

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.

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.

A modified model of conductor roughness for manufacturing copper lines of printedcircuit board

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chong Wang ◽  
Yingjie Wang ◽  
Kegu Adi ◽  
Yunzhong Huang ◽  
Yuanming Chen ◽  
...  
Keyword(s):  
Current Distribution ◽  
Transmission Lines ◽  
Design Methodology ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Modified Model ◽  
Content Type ◽  
Accurate Model ◽  
Printed Circuit ◽  
Industrial Manufacturing

Purpose The purpose of this paper is to establish an accurate model to quantify the effect of conductor roughness on insertion loss (IL) and provide improved measurements and suggestions for manufacturing good conductive copper lines of printed circuit board. Design/methodology/approach To practically investigates the modified model of conductor roughness, three different kinds of alternate oxidation treatments were used to provide transmission lines with different roughness. The IL results were measured by a vector net analyzer for comparisons with the modified model results. Findings An accurate model, with only a 1.8% deviation on average from the measured values, is established. Compared with other models, the modified model is more reliable in industrial manufacturing. Originality/value This paper introduces the influence of tiny roughness structures on IL. Besides, this paper discusses the effect of current distribution on IL.

Model updating of a temperature field simulation of a printed circuit board assembly based on the Kriging model

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yutian Yin ◽  
Hongda Zhou ◽  
Cai Chen ◽  
Yi Zheng ◽  
Hongqiao Shen ◽  
...  
Keyword(s):  
Response Surface ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit Board Assembly ◽  
Content Type ◽  
Printed Circuit ◽  
Soldering Process ◽  
New Strategy ◽  
Circuit Board Assembly ◽  
Actual Profile

Purpose The simulated temperature profile of the printed circuit board assembly (PCBA) during reflow soldering process deviates from the actual profile. To reduce this relative deviation, a new strategy based on the Kriging response surface and the Multi-Objective Genetic Algorithm (MOGA) optimizing method is proposed. Design/methodology/approach The simulated temperature profile of the PCBA during reflow soldering process deviates from the actual profile. To reduce this relative deviation, a new strategy based on the Kriging response surface and the MOGA optimizing method is proposed. Findings Several critical influencing parameters such as temperature and the convective heat transfer coefficient of the specific temperature zones are selected as the correction parameters. The hyper Latins sampling method is implemented to distribute the design points, and the Kriging response surface model of the soldering process is constructed. The updated model is achieved and validated by the test. The relative derivation is reduced from the initial value of 43.4%–11.8% in terms of the time above the liquidus line. Originality/value A new strategy based on the Kriging response surface and the MOGA optimizing method is proposed.

Contamination profile on typical printed circuit board assemblies vs soldering process

2014 ◽  
Vol 26 (4) ◽  
pp. 194-202 ◽  
Author(s):  
Helene Conseil ◽  
Morten Stendahl Jellesen ◽  
Rajan Ambat
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Content Type ◽  
Contamination Control ◽  
Conformal Coating ◽  
Printed Circuit ◽  
Soldering Process ◽  
Wave Soldering ◽  
Solder Flux ◽  
Set Up

Purpose – The purpose of this paper was to analyse typical printed circuit board assemblies (PCBAs) processed by reflow, wave or selective wave soldering for typical levels of process-related residues, resulting from a specific or combination of soldering processes. Typical solder flux residue distribution pattern, composition and concentration are profiled and reported. The effect of such contaminants on conformal coating was tested. Design/methodology/approach – Presence of localized flux residues was visualized using a commercial residue reliability assessment testing gel test and chemical structure was identified by Fourier transform infrared spectroscopy, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode set-up. Localized extraction of residue was carried out using a commercial critical contamination control extraction system. Findings – Results clearly show that the amount and distribution of flux residues are a function of the soldering process, and the level can be reduced by an appropriate cleaning. Selective soldering process generates significantly higher levels of residues compared to the wave and reflow process. For conformal coated PCBAs, the contamination levels generated from the tested wave and selective soldering process are found to be enough to generate blisters under exposure to high humidity levels. Originality/value – Although it is generally known that different soldering processes can introduce contamination on the PCBA surface, compromising its cleanliness, no systematic work is reported investigating the relative levels of residue introduced by various soldering processes and its effect on corrosion reliability.

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.

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.

High quality factor fractal inductor with complementary split-ring array inclusion

Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 215-219
Author(s):  
Akhendra Kumar Padavala ◽  
Narayana Kiran Akondi ◽  
Bheema Rao Nistala
Keyword(s):  
Quality Factor ◽  
Circuit Design ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Three Dimensional ◽  
Circuit Board ◽  
Integrated Circuit Design ◽  
Split Ring ◽  
Content Type ◽  
Practical Implications

Purpose This paper aims to present an efficient method to improve quality factor of printed fractal inductors based on electromagnetic band-gap (EBG) surface. Design/methodology/approach Hilbert fractal inductor is designed and simulated using high-frequency structural simulator. To improve the quality factor, an EBG surface underneath the inductor is incorporated without any degradation in inductance value. Findings The proposed inductor and Q factor are measured based on well-known three-dimensional simulator, and the results are compared experimentally. Practical implications The proposed method was able to significantly decrease the noise with increase in the speed of radio frequency and sensor-integrated circuit design. Originality/value Fractal inductor is designed and simulated with and without EBG surfaces. The measurement of printed circuit board prototypes demonstrates that the inclusion of split-ring array as EBG surface increases the quality factor by 90 per cent over standard fractal inductor of the same dimensions with a small degradation in inductance value and is capable of operating up to 2.4 GHz frequency range.

scholarly journals Advances in pressure sensing for vapour phase soldering process monitoring

2019 ◽  
Vol 31 (3) ◽  
pp. 169-175 ◽  
Author(s):  
Mohamed Amine Alaya ◽  
Attila Geczy ◽  
Balazs Illes ◽  
Gábor Harsányi ◽  
David Bušek
Keyword(s):  
Process Control ◽  
Printed Circuit Board ◽  
Pressure Sensors ◽  
Vapour Phase ◽  
Circuit Board ◽  
Power Functions ◽  
Monitoring Method ◽  
Content Type ◽  
Precise Control ◽  
Soldering Process

Purpose The purpose of the paper is to improve the control of vapour phase soldering (VPS). To enable better productivity and assembling quality, the industry needs to provide precise control and measurements during assembling. In the paper, a special monitoring method is presented for VPS to enable improved process control and oven state identification. Design/methodology/approach The work presents the investigation of the workspace with dynamic and gage type pressure sensors in fusion with thermocouples. Different sensors were evaluated to find an appropriate type. The relation between the temperature and the pressure was investigated, according to the setup of the oven. The effect of inserting a printed circuit board (PCB) on the pressure of the vapour inside the oven was also investigated with the pressure/power functions. Findings It was found that the novel gage-type sensors enable better precision than solutions seen in previous literature. The sensors are able to monitor the decreasing vapour concentration when a PCB is inserted to the workspace. It was found that there is a suggested minimum power to sustain a well-developed vapour column for soldering in saturated vapour. An inflexion point highlights this in the pressure/power function, in accordance with the temperature/power curve. Originality/value The research presents original works with aspects of a novel sensor fusion concept and work space monitoring for better process control and improved soldering quality.

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