scholarly journals Thermal and Electrical Analysis of Solid Aluminium Capacitors

1987 ◽  
Vol 12 (3) ◽  
pp. 167-186 ◽  
Author(s):  
E. H.L.J. Dekker ◽  
C. J.M. Lasance
Keyword(s):  
Thermal Properties ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Electronic Components ◽  
Reverse Voltage ◽  
Printed Circuit ◽  
Electrolytic Capacitors ◽  
Extensive Analysis ◽  
Current Specification ◽  
Electrical Analysis

The thermal properties of electronic components partly determine the reliability of electronic equipment. For electrolytic capacitors, they also set the limits for the ripple current and voltage values.This article first discusses the voltage limits under various conditions of temperature, frequency and polarity. Then the connection of ripple current to these parameters and to the capacitor's resistance is treated.An extensive analysis is made of the influence of heat conduction in the capacitor and the printed-circuit board, for metal-cased as well as for epoxy-coated pearl types. The study pays particular attention to solid aluminium capacitors containing a manganese dioxide semiconductor. They have some extraordinary properties: a temperature range of at least – 80 to + 175℃, and an appreciable reverse voltage potential.These can be fully employed to improve the ripple-current specification.

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.

scholarly journals Universal synthesis of conductive liquid network in polymers enabling elastic printed circuit board technology

2021 ◽  
Author(s):  
Jiheong Kang ◽  
Wonbeom Lee ◽  
Hyunjun Kim ◽  
Inho Kang ◽  
Hongjun Park ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Acoustic Field ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
System Level ◽  
Large Strains ◽  
Stretchable Electronics ◽  
Electronic Components ◽  
Conductive Liquid ◽  
Printed Circuit

Abstract Stretchable electronics are considered next-generation electronic devices in a broad range of emerging fields, including soft robotics1,2, biomedical devices3,4, human-machine interfaces5,6, and virtual or augmented reality devices7,8. A stretchable printed circuit board (S-PCB) is a basic conductive framework for the facile assembly of system-level stretchable electronics with various electronic components. Since an S-PCB is responsible for electrical communications between numerous electronic components, the conductive lines in S-PCB should strictly satisfy the following features: (i) metallic conductivity, (ii) constant electrical resistance during dynamic stretching, and (iii) tough interface bonding with various components9. Despite recent significant advances in intrinsically stretchable conductors10,11,12, they cannot simultaneously satisfy the above stringent requirements. Here, we present a new concept of conductive liquid network-based elastic conductors. These conductors are based on unprecedented liquid metal particles assembled network (LMPNet) and an elastomer. The unique assembled network structure and reconfigurable nature of the LMPNet conductor enabled high conductivity, high stretchability, tough adhesion, and imperceptible resistance changes under large strains, which enabled the first elastic-PCB (E-PCB) technology. We synthesized LMPNet through an acoustic field-driven cavitation event in the solid state. When an acoustic field is applied, liquid metal nanoparticles (LMPnano) are remarkably generated from original LMPs and assemble into a highly conductive particle network (LMPNet). Finally, we demonstrated a multi-layered E-PCB, in which various electronic components were integrated with tough adhesion to form a highly stretchable health monitoring system. Since our synthesis of LMPNet is universal, we could synthesize LMPNet in various polymers, including hydrogel, self-healing elastomer and photoresist and add new functions to LMPNet.

The Effects of Variations in Manufacturing on PCB Thermal Properties

2011 ◽  
Author(s):  
John F. Maddox ◽  
Roy W. Knight ◽  
Sushil H. Bhavnani
Keyword(s):  
Thermal Properties ◽  
Steady State ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Manufacturing Process ◽  
Printed Circuit Board ◽  
Electronic Device ◽  
Circuit Board ◽  
Printed Circuit

The thermal performance of an electronic device is heavily dependent on the properties of the printed circuit board (PCB) to which it is attached. However, even small variations in the process used to fabricate a PCB can have drastic effects on its thermal properties. Therefore, it is necessary to experimentally verify that each stage in the manufacturing process is producing the desired result. Steady state thermal resistance measurements, taken with a comparative cut bar apparatus based on ASTM D 5470-06, were used to compare PCBs manufactured from the same design by different vendors and the effects of vias filled with epoxy versus unfilled vias on the thermal resistance of a PCB. It was found that the thermal resistance of the PCBs varied by as much as 30% between vendors and that the PCBs with epoxy filled vias had a higher thermal resistance than those with unfilled vias, possibly due to the order in which the manufacturing steps were taken.

Realistic warpage evaluation of printed board assembly during reflow process

2015 ◽  
Vol 27 (4) ◽  
pp. 137-145 ◽  
Author(s):  
Soonwan Chung ◽  
Jae B. Kwak
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Contact Boundary ◽  
Electronic Components ◽  
Reflow Process ◽  
Common Component ◽  
Content Type ◽  
Printed Circuit

Purpose – This paper aims to develop an estimation tool for warpage behavior of slim printed circuit board (PCB) array while soldering with electronic components by using finite element method. One of the essential requirements for handheld devices, such as smart phone, digital camera, and Note-PC, is the slim design to satisfy the customers’ desires. Accordingly, the printed circuit board (PCB) should be also thinner for a slim appearance, which would result in decreasing the PCB’s bending stiffness. This means that PCB deforms severely during the reflow (soldering) process where the peak temperature goes up to 250°C. Therefore, it is important to estimate PCB deformation at a high temperature for thermo-mechanical quality/reliability after reflow process. Design/methodology/approach – A numerical simulation technique was devised and customized to accurately estimate the behavior of a thin printed board assembly (PBA) during reflow by considering all components, including PCB, microelectronic packages and solder interconnects. Findings – By applying appropriate constraints and boundary conditions, it was found that PBA’s warpage can be accurately predicted during the reflow process. The results were also validated by warpage measurement, which showed a fairly good agreement with one and another. Research limitations/implications – For research limitations, there are many assumptions regarding numerical modeling. That is, the viscoplastic material property of solder ball is ignored, the reflow profile is simplified and the accurate heat capacity is not considered. Furthermore, the residual stress within the PCB, generated at PCB manufacturing process, is not included in this paper. Practical implications – This paper shows how to calculate PBA warpage during the reflow process as accurately as possible. This methodology helps a PCB designer and surface-mount technology (SMT) process manager to predict a PBA warpage issue and modify PCB design before PCB real fabrication. Practically, this modeling and simulation process can be easily performed by using a graphical user interface (GUI) module, so that the engineer can handle an issue by inputting some numbers and clicking some buttons. Social implications – In a common sense manner, a numerical simulation method can decrease time and cost in manufacturing real samples. This PCB warpage method can also decrease product development duration and produce a new product earlier. Furthermore, PCB is a common component in all the electronic devices. So, this PCB warpage method can have various applications. Originality/value – Because of an economic advantage, the development of a numerical simulation tool for estimating the thin PBA warpage behaviour during reflow process was attempted. The developed tool contains the features of detailed modeling for electronic components and contact boundary conditions of the supporting rails in the reflow oven.

scholarly journals Traceability of printed circuit board assemblies using embedded electronic components

2020 ◽  
Vol 14 (8) ◽  
pp. 785-790
Author(s):  
Kamil Janeczek ◽  
Aneta Araźna ◽  
Wojciech Stęplewski ◽  
Tomasz Serzysko
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Electronic Components ◽  
Printed Circuit

Structure analysis of the conical heating hole for waste printed circuit boards disassembly

2020 ◽  
pp. 095440622093153
Author(s):  
Fengfu Yin ◽  
Tianhao Chang ◽  
Lin Li ◽  
Huiguang Bian ◽  
Kongshuo Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Energy Consumption ◽  
Printed Circuit Board ◽  
Melting Process ◽  
Circuit Board ◽  
Electronic Components ◽  
Printed Circuit ◽  
Waste Printed Circuit Board ◽  
Hot Air ◽  
Wide Range

The component disassembling technology of printed circuit board is taking on more importance in the field of electronic waste disassembly. When disassembling electronic components from waste printed circuit board, its implementation programs are to inject hot air into printed circuit board through spray nozzle and melt the solder joints through thermal convection. The structure of air heating outlet for disassembling electronic components from waste printed circuit board is investigated to reduce energy consumption in solder melting process. This paper proposes a structural analysis method of conical heating holes to reduce the energy consumption of hot air and improve the temperature uniformity in solder melting process. With advantages of high efficiency and low-cost, numerical simulation method is totally used to obtain optimal dimension parameters of the conical hole from a wide range of optional parameters. The numerical simulation takes air as the heating medium and adopts the mode of heat convection under optimal melting temperature range (200–230 ℃). The optimized results of the parameters of a single conical hole and multiple conical holes are obtained based on numerical simulation. When the distance between the inlet and the substrate is 50 mm, the optimal inlet temperature and velocity are 235 ℃ and 8 m/s, respectively. For a single conical hole, the optimal inlet height, top diameter, and angle are 6 mm, 16 mm, and 20°, respectively. For multiple conical holes, the optimal distance between the center lines of two inlet ranges from 50 mm to 56 mm.

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