scholarly journals A Technique for Detecting Moisture Absorption in Printed Circuit Boards

2020 ◽  
Vol 17 (1) ◽  
pp. 28-33
Author(s):  
Jeffery D. Craven ◽  
Ariel R. Oldag ◽  
Robert N. Dean
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Moisture Absorption ◽  
Low Cost ◽  
Circuit Board ◽  
Sensor Technology ◽  
Circuit Boards ◽  
Liquid Form ◽  
Printed Circuit ◽  
Fringing Field

Abstract Most circuit boards operate in environments that have the potential to be exposed to moisture, either in vapor or liquid form. Because low-cost circuit boards can readily absorb moisture, this can lead to performance issues, reliability issues, and even catastrophic failure. However, it is difficult to detect if moisture absorption has occurred before the circuit board suffers a complete failure. To alleviate this issue, a fringing field capacitor was implemented in printed circuit board (PCB) technology and used to detect the absorption of moisture in the circuit board through the accompanying increase in capacitance. Prototype sensors were fabricated and immersed for 42 d, demonstrating an increase in capacitance of between 14% and 29%. This sensor technology can easily be added to circuit board designs because they use the standard materials and fabrication processes used in commercial PCB construction.

scholarly journals Design and Implementation of Solder Paste Dispenser Based on Linear Drive System

2019 ◽  
Vol 3 (2) ◽  
pp. 338
Author(s):  
Riky Tri Yunardi ◽  
Moh. Zakky Zulfiar ◽  
Rr. Wanda Auruma Putri ◽  
Deny Arifianto
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Circuit Board ◽  
Solder Paste ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Design And Implementation ◽  
Stepper Motors ◽  
Drive Systems

In the technology to create prototypes for electronic hardware is usually constructed using surface mount device printed circuit board (SMD PCB). In this paper introduces the design and implementation of low-cost electrical solder paste dispenser that supports the PCB solder process. The design consists of a nozzle and linear drive systems based on stepper motors operating with electric power to push the plunger down to drop the solder paste on the board. To test the performance of solder paste that has been designed verified by experiment. Solder paste dispenser design was tested using SMD resistor with the solder pads of different sizes for R0603, R0805, and R1206 on PCB. The results showed that the design of the prototype was able to put the pasta in various field pads between 0.54 mm2, 0.91 mm2 and 1.44 mm2 for standard solder pads with an error in the 2% - 5%. Based on the results, the device has been shown to potentially be used to attach electronic components to printed circuit boards.

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.

A PCB Sensor for Magnetic Materials

2019 ◽  
Vol 2019 (DPC) ◽  
pp. 001323-001342
Author(s):  
Robert N. Dean ◽  
Lauren E. Beckingham
Keyword(s):  
Magnetic Materials ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Complex Impedance ◽  
Corrosion Products ◽  
Physical Contact ◽  
Circuit Board ◽  
Sensor Technology ◽  
Printed Circuit ◽  
Surrounding Environment

Printed circuit board (PCB) sensors are a sensor technology where the layout of traces on a PCB has been optimized so that the traces electromagnetically interact with the surrounding environment. These types of sensors can be manufactured at very low cost using standard commercially available low-cost printed circuit board fabrication. Exposed conductive electrodes on the circuit board are useful for measuring the electrical conductivity of the surrounding environment, and these sensors have been used in applications such as salinity measurement and dissolved ion content measurement of aqueous solutions. Insulated interdigitated electrode sensors are useful for capacitively analyzing the surrounding environment, and these sensors have been used to detect the presence of liquid water and to measure the moisture content of substances in physical contact with the sensor. Additionally, by measuring the complex impedance of the capacitive sensor over a wide frequency range, information concerning the chemical composition of the substance in contact with the sensor can be determined. In addition to conducive and capacitive PCB sensors, the third type of PCB sensor would be an inductive sensor. Although it is challenging to realize 3D coils in PCB technology, planar inductors can be realized in a single Cu layer on a PCB, and insulated from the environment using a cover layer of polymeric solder mask. This type of electrode structure can inductively couple with magnetic materials in close proximity to the sensor. A variety of magnetic materials exist, including iron, nickel and cobalt. Additionally, many alloys of these elements are also magnetic. Of particular interest are corrosion products with magnetic properties, such as iron(III) oxide, Fe3O2, also known as common rust. A thin layer of iron(III) oxide powder deposited on the sensor's active area results in a measureable increase in the sensor's inductance. As such, an inductive PCB sensor could be a low-cost option for detecting the presence of some corrosion products in its operating environment.

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.

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.

Advanced Materials for Printed Circuit Boards

1987 ◽  
Vol 108 ◽  
Author(s):  
David Wei Wang
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
High Reliability ◽  
Circuit Board ◽  
Advanced Materials ◽  
Impregnation Method ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Worldwide Production ◽  
Board Industry

The printed circuit board is an integral part of the electronic packaging hierarchy. Its use began more than 40 years ago, and the demand for printed circuit boards has increased in parallel with the growth of the electronics industry.[1] According to a recent forecast, the worldwide production of printed circuit boards will reach to over 19 billion U.S. dollars' worth by 1990.[2] With continuing demands for more interconnections, the multilayer circuit board industry is experiencing its fastest growth rate. Boards with more than 20 inner planes of circuitry are being manufactured with high reliability.Based on dollar values, more than 90% of the circuit boards produced are in the rigid board category, where starting materials are based on thermosetting prepregs produced by a solution impregnation method. This article is a review of materials currently used in rigid composites.

scholarly journals MODIFICATION OF TOOL FOR MOVING TRACK SEGMENTS IN DELTA DESIGN CAD

2019 ◽  
pp. 130-133
Author(s):  
A. Yu. Gladkevich
Keyword(s):  
Computer Aided Design ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Design System ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Advantages And Disadvantages ◽  
Development Tools ◽  
Aided Design

Describes the process of improving and developing tools in computer‑aided design system Delta Design. Currently, the modern  process of PCB development is quite complex and time‑consuming process. Existing CAD systems make it easier to design a  printed circuit Board model by providing powerful development tools. Along with the increasing complexity of modern printed  circuit boards, the requirements for development tools are also growing, making them constantly improve. Using the example  of  the  Delta  Design  system,  the  process  of  improving  the  tool  for  moving  track  segments  is  described.  The  analysis  of  the  advantages and disadvantages of the existing tool is made, and the decision on the need to develop a new algorithm is justified.  Of the two proposed variants of such an algorithm, the optimal one was chosen in terms of the quality of the result obtained and  the convenience of operation.

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