Thermal Management of Heat Generating Devices in Close Proximity on Printed Circuit Boards

2005 ◽  
Author(s):  
Jared Harvest ◽  
Amy S. Fleischer ◽  
Randy D. Weinstein
Keyword(s):  
Thermal Management ◽  
Printed Circuit Boards ◽  
Separation Distance ◽  
Circuit Board ◽  
Circuit Boards ◽  
Optimal Operating ◽  
Printed Circuit ◽  
Close Proximity ◽  
Board Material ◽  
Dynamics Models

This study uses experimentally validated computational fluid dynamics models to predict the behavior of the localized thermal interactions between adjacent components on vertically orientated circuit boards in natural convection. Using the developed models, the effects of power density, component proximity, component geometry, circuit board material, board packing density and board separation distance on the maintenance of optimal operating temperatures for all components are investigated. The device separation distance beyond which the components no longer thermally influence each other is identified and the influence of various parameters on this distance is studied. The parametric study is designed using Design of Experiments methodology to best interpret the interaction between parameters and can easily be applied to other packaging situations to allow designers to optimally place components on a circuit board in close proximity to minimize negative thermal interactions.

Dielectric Breakdown in Printed Circuit Boards at Elevated Temperatures

1996 ◽  
Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh
Keyword(s):  
Experimental Data ◽  
Thermal Degradation ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Elevated Temperatures ◽  
Dielectric Breakdown ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Data Matching

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.

scholarly journals A model for the reflection of terahertz signals from printed circuit board surfaces

2018 ◽  
Vol 10 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Alexander Fricke ◽  
Mounir Achir ◽  
Philippe Le Bars ◽  
Thomas Kürner
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Simulated Annealing Algorithm ◽  
Specular Reflection ◽  
Circuit Board ◽  
Network Analyzer ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Propagation Modeling ◽  
Annealing Algorithm

AbstractBased on vector network analyzer Measurements, a model for the specular reflection behavior of printed circuit boards in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for integration to ray-tracing-based propagation modeling.

scholarly journals NotchPUF: Printed Circuit Board PUF Based on Microstrip Notch Filter

Cryptography ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 11
Author(s):  
Mitchell Martin ◽  
Jim Plusquellic
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Statistical Tests ◽  
Notch Filter ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
In Series ◽  
Commercial Off The Shelf ◽  
Using Data

Physical Unclonable Functions (PUFs) are primitives that are designed to leverage naturally occurring variations to produce a random bitstring. Current PUF designs are typically implemented in silicon or utilize variations found in commercial off-the-shelf (COTS) parts. Because of this, existing designs are insufficient for the authentication of Printed Circuit Boards (PCBs). In this paper, we propose a novel PUF design that leverages board variations in a manufactured PCB to generate unique and stable IDs for each PCB. In particular, a single copper trace is used as a source of randomness for bitstring generation. The trace connects three notch filter structures in series, each of which is designed to reject specific but separate frequencies. The bitstrings generated using data measured from a set of PCBs are analyzed using statistical tests to illustrate that high levels of uniqueness and randomness are achievable.

Downsizing an automotive junction box based on large current-carrying printed-circuit board optimization

2016 ◽  
Vol 231 (2) ◽  
pp. 267-278 ◽  
Author(s):  
Hansang Lim ◽  
Do-Hwan Jung ◽  
Geono Kwon ◽  
Young Jong Lee ◽  
Jun Seo Park
Keyword(s):  
Power Distribution ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Installation Space ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Overcurrent Protection ◽  
Large Current ◽  
Analytical Estimation

An automotive junction box distributes electric power to electric systems installed in a vehicle with overcurrent protection. As a larger number of electric systems are installed, the junction box is equipped with more components, functionalities and connections. However, owing to the fuse accessibility, its installation space is so restricted that a downsized design is required for the junction box. The junction box is composed of small signal circuitry for control and monitoring, and large current-carrying circuitry for power distribution which includes many parallel traces. Because of these unique features, widely used techniques for downsizing printed-circuit boards are not applicable. Also, there is no rule for designing large current-carrying parallel traces, and it is difficult to optimize the size of the printed-circuit board for the automotive junction box. This paper presents the design rules for a printed-circuit board when downsizing a junction box. First, the layout strategy for the power distribution components is presented, which is determined by the sum of the squares of the currents flowing through connector pairs. Then, the thermal effects of parallel traces are simulated for different conditions by using thermal analysis software. Based on the results, an analytical estimation of the additional temperature rises due to parallel traces and rules for a thermally effective arrangement of the parallel traces are presented.

scholarly journals Separation and Recovery of Fine Particles from Waste Circuit Boards Using an Inflatable Tapered Diameter Separation Bed

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chenlong Duan ◽  
Cheng Sheng ◽  
Lingling Wu ◽  
Yuemin Zhao ◽  
Jinfeng He ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Printed Circuit Boards ◽  
Fine Particles ◽  
Metal Recovery ◽  
Circuit Board ◽  
Circuit Boards ◽  
Recovery Rates ◽  
Operational Conditions ◽  
Printed Circuit ◽  
Wide Range

Recovering particle materials from discarded printed circuit boards can enhance resource recycling and reduce environmental pollution. Efficiently physically separating and recovering fine metal particles (−0.5 mm) from the circuit boards are a key recycling challenge. To do this, a new type of separator, an inflatable tapered diameter separation bed, was developed to study particle motion and separation mechanisms in the bed’s fluid flow field. For 0.5–0.25 mm circuit board particles, metal recovery rates ranged from 87.56 to 94.17%, and separation efficiencies ranged from 87.71 to 94.20%. For 0.25–0.125 mm particles, metal recovery rates ranged from 84.76 to 91.97%, and separation efficiencies ranged from 84.74 to 91.86%. For superfine products (−0.125 mm), metal recovery rates ranged from 73.11 to 83.04%, and separation efficiencies ranged from 73.00 to 83.14%. This research showed that the inflatable tapered diameter separation bed achieved efficient particle separation and can be used to recover fine particles under a wide range of operational conditions. The bed offers a new mechanical technology to recycle valuable materials from discarded printed circuit boards, reducing environmental pollution.

Future paper based printed circuit boards for green electronics: fabrication and life cycle assessment

2014 ◽  
Vol 7 (11) ◽  
pp. 3674-3682 ◽  
Author(s):  
Jingping Liu ◽  
Cheng Yang ◽  
Haoyi Wu ◽  
Ziyin Lin ◽  
Zhexu Zhang ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impact ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Future Paper ◽  
Printing Paper

A multilayer printed circuit board (PCB) can be fabricated using commercially available printing paper, which shows comparable functionalities with the conventional organic PCBs but 100 times lower environmental impact.

New technologies of multi-layered printed circuit boards, intended of rapid-design electronic modules

Circuit World ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 121-124
Author(s):  
Wojciech Stęplewski ◽  
Mateusz Mroczkowski ◽  
Radoslav Darakchiev ◽  
Konrad Futera ◽  
Grażyna Kozioł
Keyword(s):  
Printed Circuit Boards ◽  
New Technologies ◽  
Circuit Board ◽  
Circuit Boards ◽  
Content Type ◽  
Signal Distribution ◽  
Printed Circuit ◽  
Rapid Design ◽  
Small Pitch ◽  
Signal Path

Purpose – The purpose of this study was the use of embedded components technology and innovative concepts of the printed circuit board (PCB) for electronic modules containing field-programmable gate array (FPGA) devices with a large number of pins (e.g. Virtex 6, FF1156/RF1156 package, 1,156 pins). Design/methodology/approach – In the multi-layered boards, embedded passive components that support FPGA device input/output (I/O), such as blocking capacitors and pull-up resistors, were used. These modules can be used in rapid design of electronic devices. In the study, the MC16T FaradFlex material was used for the inner capacitive layer. The Ohmega-Ply RCM 25 Ω/sq material was used to manufacture pull-up resistors for high-frequency pins. The embedded components have been connected to pins of the FPGA component by using plated-through holes for capacitors and blind vias for resistors. Also, a technique for a board-to-board joining, by using castellated terminations, is described. Findings – The fully functional modules for assembly of the FPGA were manufactured. Achieved resistance of embedded micro resistors, as small as the smallest currently used surface-mount device components (01005), was below required tolerance of 10 per cent. Obtained tolerance of capacitors was less than 3 per cent. Use of embedded components allowed to replace the pull-up resistors and blocking capacitors and shortens the signal path from the I/O of the FPGA. Correct connection to the castellated terminations with a very small pitch was also obtained. This allows in further planned studies to create a full signal distribution system from the FPGA without the use of unreliable plug connectors in aviation and space technology. Originality/value – This study developed and manufactured several innovative concepts of signal distribution from printed circuit boards. The signal distribution solutions were integrated with embedded components, which allowed for significant reduction in the signal path. This study allows us to build the target object that is the module for rapid design of the FPGA device. Usage of a pre-designed module would lessen the time needed to develop a FPGA-based device, as a significant part of the necessary work (mainly designing the signal and power fan-out) will already be done during the module development.

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