scholarly journals The Physics of Interdigitated Dielectrometry Sensors and Application as In-Situ Oil Oxidation Monitoring

2021 ◽  
Author(s):  
◽  
Alexander Risos
Keyword(s):  
Dielectric Properties ◽  
Complex Permittivity ◽  
Relative Permittivity ◽  
Printed Circuit Board ◽  
Theory Model ◽  
Circuit Board ◽  
Oil Degradation ◽  
Thermal Oil ◽  
The Impact

<p>Monitoring of hydrocarbon oxidation is of great importance in many industry applications and reliable in-situ measurements are a challenge. In literature, it was shown that new versus degraded hydrocarbons show a change in their dielectric properties. In this thesis, the degradation of the oil was investigated by means of two thermal oil degradation experiments and the Fourier transform infrared spectroscopy. In addition, the impact. on the dielectric properties were determined using a novel type of a dielectric test cell that is temperature  compensated. It was found that ketones, acids and moisture were generated through a thermal oil aging process. These products have been found to change in the dielectric properties of the liquid which are reflected through the complex permittivity. Ketones increased largely the real part of the permittivity and organic acids affected predominantly the imaginary part of the complex permittivity in a nonlinear fashion, which could be described using a modified polaron theory model. These measurements served as the base for the development of a novel kind of interdigitated sensor that can measure the dielectric properties such as the relative permittivity and the intrinsic conductivity with high accuracy and precision, without being affected by temperature. This is a crucial step in the development of a suitable in-situ sensor, as it does not need to undergo a complicated temperature curve compensation or calibration using calibration-liquids. The interdigitated sensor, made using cost efficient printed circuit board technology, exhibited an accuracy in measuring the complex permittivity of about 99%. The sensing precision was practically limited by the measurement instrumentation using a developed Faraday shield for the sensor. The sensor was used in an oil degradation experiment. to verify the in-situ capability. These measurements of the relative permittivity and conductivity yielded values such as a degree of oxidation and acidity number. For the first time: it was possible to measure in-situ the complex dielectric properties of liquids at temperatures between 20 °C to 140 °C using interdigitated sensors.</p>

scholarly journals The Physics of Interdigitated Dielectrometry Sensors and Application as In-Situ Oil Oxidation Monitoring

2021 ◽  
Author(s):  
◽  
Alexander Risos
Keyword(s):  
Dielectric Properties ◽  
Complex Permittivity ◽  
Relative Permittivity ◽  
Printed Circuit Board ◽  
Theory Model ◽  
Circuit Board ◽  
Oil Degradation ◽  
Thermal Oil ◽  
The Impact

<p>Monitoring of hydrocarbon oxidation is of great importance in many industry applications and reliable in-situ measurements are a challenge. In literature, it was shown that new versus degraded hydrocarbons show a change in their dielectric properties. In this thesis, the degradation of the oil was investigated by means of two thermal oil degradation experiments and the Fourier transform infrared spectroscopy. In addition, the impact. on the dielectric properties were determined using a novel type of a dielectric test cell that is temperature  compensated. It was found that ketones, acids and moisture were generated through a thermal oil aging process. These products have been found to change in the dielectric properties of the liquid which are reflected through the complex permittivity. Ketones increased largely the real part of the permittivity and organic acids affected predominantly the imaginary part of the complex permittivity in a nonlinear fashion, which could be described using a modified polaron theory model. These measurements served as the base for the development of a novel kind of interdigitated sensor that can measure the dielectric properties such as the relative permittivity and the intrinsic conductivity with high accuracy and precision, without being affected by temperature. This is a crucial step in the development of a suitable in-situ sensor, as it does not need to undergo a complicated temperature curve compensation or calibration using calibration-liquids. The interdigitated sensor, made using cost efficient printed circuit board technology, exhibited an accuracy in measuring the complex permittivity of about 99%. The sensing precision was practically limited by the measurement instrumentation using a developed Faraday shield for the sensor. The sensor was used in an oil degradation experiment. to verify the in-situ capability. These measurements of the relative permittivity and conductivity yielded values such as a degree of oxidation and acidity number. For the first time: it was possible to measure in-situ the complex dielectric properties of liquids at temperatures between 20 °C to 140 °C using interdigitated sensors.</p>

A Coplanar Waveguide Resonator Based In-Line Material Characterization Sensor for Bulk and Metallized Dielectrics

Frequenz ◽  
2017 ◽  
Vol 71 (3-4) ◽  
Author(s):  
Armin Talai ◽  
Gerald Gold ◽  
Martin Frank ◽  
Sebastian Mann ◽  
Robert Weigel ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Resonance Frequency ◽  
Antenna Arrays ◽  
Complex Permittivity ◽  
Relative Permittivity ◽  
Coplanar Waveguide ◽  
Distribution Networks ◽  
Circuit Board ◽  
Resonance Frequencies ◽  
The Impact

AbstractMicrowave Materials such as Rogers RO3003 are subject to process-related fluctuations in terms of the relative permittivity and dielectric loss. The behavior of high frequency circuits like patch-antenna arrays and their distribution networks is dependent on the effective wavelength. Therefore, fluctuations of the complex permittivity will influence the resonance frequency and beam direction of the antennas. This paper presents a grounded coplanar waveguide based sensor, which can measure the complex permittivity at 77 GHz, as well as at other resonance frequencies, by applying it on top of the manufactured depaneling. The relative permittivity of the material under test (MUT) is a function of the resonance frequency shift and the dielectric loss of the MUT can be determined by transmission amplitude variations at the resonances. In addition, the sensor is robust against floating ground metallizations on inner printed circuit board layers, which are typically distributed over the entire surface below antennas. Furthermore, the impact from conductor surface roughness on the measured permittivity values is determined using the Gradient Model.

In-Situ Mechanical Sample Preparation of Selected Sites and Components on Large Modules and Boards

2016 ◽  
Author(s):  
Jim Colvin ◽  
Timothy Hazeldine ◽  
Heenal Patel
Keyword(s):  
Sample Preparation ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Tilt Table ◽  
Standard Requirement ◽  
Open Design ◽  
Bga Packages ◽  
Silicon Thickness ◽  
Board Level

Abstract The standard requirement for FA Engineers needing to remove components from a board, prior to decapsulation or sample preparation, is shown to be greatly reduced, by the methods discussed here. By using a mechanical selected area preparation system with an open-design it is possible to reach all required areas of a large printed circuit board (PCB) or module to prepare a single component ‘in situ’. This makes subsequent optical or electrical testing faster and often more convenient to accomplish. Electronic End-pointing and 3D curvature compensation methods can often be used in parallel with sample prep techniques to further improve the consistency and efficacy of the decapsulation and thinning uniformity and final remaining silicon thickness (RST). Board level prep eliminates the worry of rework removal of BGA packages and the subsequent risk of damage to the device. Since the entire board is mounted, the contamination is restricted to the die surface and can be kept from the underside ball connections unlike current liquid immersion methods of package thinning or delayering. Since the camera is in line with the abrasion interface, imaging is real time during the entire milling and thinning process. Recent advances in automated tilt-table design have meant that a specific component’s angular orientation can be optimized for sample preparation. Improved tilt table technology also allows for improved mounting capability for boards of many types and sizes. The paper describes methods for decapsulation, thinning and backside polishing of a part ‘in situ’ on the polishing machine and allows the system to operate as a probe station for monitoring electrical characteristics while thinning. Considerations for designing board-level workholders are described – for boards that that are populated with components on one or even both sides. Using the techniques described, the quality of sample preparation and control is on a par with the processing of single package-level devices.

Numerical Simulation and Experimental Measurement of a Printed Circuit Board Subjected to Drop Test

2009 ◽  
Vol 419-420 ◽  
pp. 37-40
Author(s):  
Shiuh Chuan Her ◽  
Shien Chin Lan ◽  
Chun Yen Liu ◽  
Bo Ren Yao
Keyword(s):  
Finite Element ◽  
Experimental Measurement ◽  
Test Specimen ◽  
Printed Circuit Board ◽  
Drop Impact ◽  
Simulation Technique ◽  
Drop Test ◽  
Circuit Board ◽  
Printed Circuit ◽  
The Impact

Drop test is one of the common methods for determining the reliability of electronic products under actual transportation conditions. The aim of this study is to develop a reliable drop impact simulation technique. The test specimen of a printed circuit board is clamped at two edges on a test fixture and mounted on the drop test machine platform. The drop table is raised at the height of 50mm and dropped with free fall to impinge four half-spheres of Teflon. One accelerometer is mounted on the center of the specimen to measure the impact pulse. The commercial finite element software ANSYS/LS-DYNA is applied to compute the impact acceleration and dynamic strain on the test specimen during the drop impact. The finite element results are compared to the experimental measurement of acceleration with good correlation between simulation and drop testing. With the accurate simulation technique, one is capable of predicting the impact response and characterizing the failure mode prior to real reliability test.

scholarly journals Implementation and Experimental Verification of Smart Junction Box for Low-Voltage Automotive Electronics in Electric Vehicles

2020 ◽  
Vol 10 (7) ◽  
pp. 2214
Author(s):  
Sang Wook Lee ◽  
Soo-Whang Baek
Keyword(s):  
Electric Vehicles ◽  
Printed Circuit Board ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Short Circuit ◽  
Circuit Board ◽  
Area Network ◽  
Automotive Electronics ◽  
Overload Protection ◽  
The Impact

In this study, we designed and implemented a smart junction box (SJB) that was optimized for supplying power to low-voltage headlights (13.5 V) in electric vehicles. The design incorporated a number of automotive semiconductor devices, and components were placed in a high-density arrangement to reduce the overall size of the final design. The heat generated by the SJB was efficiently managed to mount an Intelligent Power Switch (IPS), which was used to power the headlights onto the printed circuit board (PCB) to minimize the impact on other components. The SJB was designed to provide power to the headlights via pulse width modulation to extend their lifetime. In addition, overload protection and fail/safe functions were implemented in the software to improve the stability of the system, and a controller area network (CAN) bus was provided for communications with various components in the SJB as well as with external controllers. The performance of the SJB was validated via a load operation test to assess the short circuit and overload protection functions, and the output duty cycle was evaluated across a range of input voltages to ensure proper operation. Based on our results, the power supplied to the headlights was found to be uniform and stable.

Research on Liberation Mechanism of the Impact Crushing Waste Printed Circuit Board

2010 ◽  
Vol 113-116 ◽  
pp. 730-734 ◽  
Author(s):  
Chen Long Duan ◽  
Yue Min Zhao ◽  
Jing Feng He ◽  
Nian Xin Zhou
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Distribution Model ◽  
Evaluation Indexes ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Impact Crushing ◽  
The Impact

The reutilization of waste Printed Circuit Boards (PCB) is a focused topic in the field of environment protection and resource recycling, and the crushing is the crucial process for recycling waste PCB. A hamper impacting crusher was used to achieve metals crushing liberation from non-metals, the liberation mechanism of PCB can be explained by dispersion liberation accompanied disengaging liberation. The Rosin-Rammler distribution model of crushed PCB particle was put forward. The evaluation indexes show that Rosin-Rammler function can accurately describe size distribution of PCB particles because the convergence property R2 is 0.99694 and fitting error E is 4.80658. The selective crushing is appearance with metals concentrated in coarser fraction and non-metals in finer size during comminution processing. The impact crushing is an effective method to metals liberation of PCB particles.

Failure Analysis of Halogen-Free Printed Circuit Board Assembly Under Board-Level Drop Test

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hung-Jen Chang ◽  
Chau-Jie Zhan ◽  
Tao-Chih Chang ◽  
Jung-Hua Chou
Keyword(s):  
Printed Circuit Board ◽  
Drop Test ◽  
Circuit Board ◽  
Printed Circuit Board Assembly ◽  
Printed Circuit ◽  
Plastic Ball ◽  
Circuit Board Assembly ◽  
Halogen Free ◽  
Board Level ◽  
The Impact

In this study, a lead-free dummy plastic ball grid array component with daisy-chains and Sn4.0Ag0.5Cu Pb-free solder balls was assembled on an halogen-free high density interconnection printed circuit board (PCB) by using Sn1.0Ag0.5Cu solder paste on the Cu pad surfaces of either organic solderable preservative (OSP) or electroless nickel immersion gold (ENIG). The assembly was tested for the effect of the formation extent of Ag3Sn intermetallic compound. Afterward a board-level pulse-controlled drop test was conducted on the as-reflowed assemblies according to the JESD22-B110 and JESD22-B111 standards, the impact performance of various surface finished halogen-free printed circuit board assembly was evaluated. The test results showed that most of the fractures occurred around the pad on the test board first. Then cracks propagated across the outer build-up layer. Finally, the inner copper trace was fractured due to the propagated cracks, resulting in the failure of the PCB side. Interfacial stresses numerically obtained by the transient stress responses supported the test observation as the simulated initial crack position was the same as that observed.

Nonlinear Response of a Printed Circuit Board in Shock

2009 ◽  
Author(s):  
M. Vujosevic ◽  
P. Raghavan ◽  
G. Ramanathan ◽  
W. Hezeltine ◽  
K. Blue
Keyword(s):  
Printed Circuit Board ◽  
Transfer Functions ◽  
Numerical Approach ◽  
Circuit Board ◽  
Special Importance ◽  
Strain Measurements ◽  
Printed Circuit ◽  
Numerical Finite Element ◽  
Nonlinear Deformations ◽  
The Impact

This work focuses on deformation mechanisms taking place in a Printed Circuit Board (PCB) exposed to high impact shock. A combined experimental, theoretical, and numerical approach has been applied to address both the nature of the observed deformation and its modeling and test metrology implications. Experimental evidence overwhelmingly indicates that a PCB in both test and system applications undergoes nonlinear deformations. Geometric nonlinearity of board response is attributed to the elevated in-plane (membrane) stresses that develop when a drop height and/or inertia forces are significant. The impact of these stresses on deformations (board strain) was quantified using a specially designed test. Membrane stresses were also accounted for in a numerical (Finite Element Method) model developed and carefully validated in the course of this study. The model shows a very good agreement with test data. The nonlinearity of PCB deformation in shock, i.e. the fact that both bending moments and in-plane forces are present in the board has important implications on test metrology development and on correlation between the measured board strain and stresses in interconnects of surface mounted components. Of special importance is the impact that nonlinearity can have on development of transfer functions between strain measurements on system boards and strain measurements on test boards, which is also addressed in the paper.

Estimation Of Complex Permittivity Of Printed Circuit Board Material Using Waveguide Measurements

1996 ◽  
Vol 430 ◽  
Author(s):  
C. J. Reddy ◽  
M. D. Deshpande ◽  
G. A. Hanidu
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Complex Permittivity ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
The Finite Element Method ◽  
Printed Circuit ◽  
X Band ◽  
Board Material ◽  
Raphson Method

AbstractA simple waveguide measurement technique is presented to determine the complex permittivity of printed circuit board material. The printed circuit board with metal coating removed from both sides and cut into size which is the same as the cross section of the waveguide is loaded in a short X-band rectangular waveguide. Using a network analyzer, the reflection coefficient of the shorted waveguide(loaded with the sample) is measured. Using the Finite Element Method(FEM) the exact reflection coefficient of the shorted wavguide(loaded with the sample) is determined as a function of dielectric constant. Matching the measured value of the reflection coefficient with the reflection value calculated using FEM and utilizing Newton-Raphson Method, an estimate of the dielectric constant of a printed circuit board material is obtained. A comparison of estimated values of permittivity constant obtained using the present approach with the available data.

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