Self-Oscillating Microcantilever Piezoresistive Flow Sensor

2006 ◽  
Vol 326-328 ◽  
pp. 1347-1350
Author(s):  
Jeung Sang Go ◽  
Bo Sung Shin ◽  
Jong Soo Ko
Keyword(s):  
Gas Flow ◽  
Printed Circuit Board ◽  
Fluid Velocity ◽  
Flow Sensor ◽  
Circuit Board ◽  
Flow Induced Vibration ◽  
Peak Voltage ◽  
New Approach ◽  
Inlet Velocity ◽  
Microfabrication Technology

This article presents a new approach to measure the fluid velocity using the flow-induced vibration of a microcantilever. The gas flow sensor was fabricated using the microfabrication technology and mounted on a printed circuit board for experimental evaluation. For signal processing, a Wheastone bridge circuit was prepared. The experimental measurement of the fluid velocity was performed in the wind tunnel. The flow-induced vibration of the microcantilever was firstly visualized. Based on the power spectrum analysis, the vibrating frequency was constant at 1.173 kHz, independently of the inlet velocity. It is completely different from the conventional flow-induced vibration proportional to the inlet velocity. The peak-to-peak voltage outputs corresponding to the air velocities of 3, 4, 5 and 6 m/s were measured.

Numerical Investigation of Heat Transfer of Twelve Plastic Leaded Chip Carrier (PLCC) by Using Computational Fluid Dynamic, FLUENTTM Software

2013 ◽  
Vol 795 ◽  
pp. 603-610 ◽  
Author(s):  
Mohamed Mazlan ◽  
A. Rahim ◽  
M.A. Iqbal ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
W. Razak ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Circuit Board ◽  
Junction Temperature ◽  
Inlet Velocity ◽  
Chip Carrier ◽  
Flow Through ◽  
Package Density ◽  
Heat And Fluid Flow

Plastic Leaded Chip Carrier (PLCC) package has been emerged a promising option to tackle the thermal management issue of micro-electronic devices. In the present study, three dimensional numerical analysis of heat and fluid flow through PLCC packages oriented in-line and mounted horizontally on a printed circuit board, is carried out using a commercial CFD code, FLUENTTM. The simulation is performed for 12 PLCC under different inlet velocities and chip powers. The contours of average junction temperatures are obtained for each package under different conditions. It is observed that the junction temperature of the packages decreases with increase in inlet velocity and increases with chip power. Moreover, the increase in package density significantly contributed to rise in temperature of chips. Thus the present simulation demonstrates that the chip density (the number of packages mounted on a given area), chip power and the coolant inlet velocity are strongly interconnected; hence their appropriate choice would be crucial.

A new approach to investigate conductive anodic filament (CAF) formation

2015 ◽  
Vol 27 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Ling Chunxian Zou ◽  
Chris Hunt
Keyword(s):  
Printed Circuit Board ◽  
Flexible Substrate ◽  
Test Sample ◽  
Circuit Board ◽  
Reflow Process ◽  
New Approach ◽  
Content Type ◽  
Glass Fibres ◽  
Short Period ◽  
Conductive Anodic Filament

Purpose – This paper aims to describe the development of an approach that uses a flexible substrate to investigate the mechanism of conductive anodic filament (CAF) growth and effect of different material and manufacturing variables. Design/methodology/approach – A new approach using a simulated test vehicle (STV) has been developed to study the CAF phenomena. The STV can be easily built under controlled conditions in the laboratory using different glass fibres and resin powder to investigate the effect of different variables separately on CAF. The advantage of the STV is that CAF can be formed in relatively short period in a controlled way, and CAF growth can be easily identified using a back-lighting under a microscope due to the thin flex material used as the test sample. Findings – STV has been used to investigate a number of effects on CAF formation: different glass fibres, reflow process, acid contamination in drilled holes, desmear process and glass bundle size. The results demonstrate that for finished fibres acid contamination (plating solution) at the electrode was necessary for CAF formation. However, for unfinished glass fibres (loom state and heat cleaned) CAF can be formed without acid contamination. The reflow process significantly increases CAF formation. Running an aggressive desmear process and using large glass fibre bundle also increased CAF formation. Originality/value – This new approach will be of benefit for printed circuit board (PCB) supplier to evaluate CAF performance on different resin systems and glass fibres to provide high CAF resistance quality PCBs. The test period (168 hours) would be much shorter than the traditional CAF testing (1,000 hours).

scholarly journals Fabrication and Evaluation of a Flexible MEMS-Based Microthermal Flow Sensor

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8153
Author(s):  
Myoung-Ock Cho ◽  
Woojin Jang ◽  
Si-Hyung Lim
Keyword(s):  
Flow Velocity ◽  
Output Voltage ◽  
Gas Flow ◽  
Fluid Velocity ◽  
Wheatstone Bridge ◽  
Polyimide Film ◽  
Flow Sensor ◽  
Healthcare Applications ◽  
Labview Software ◽  
Liquid Flows

Based on the results of computational fluid dynamics simulations, this study designed and fabricated a flexible thermal-type micro flow sensor comprising one microheater and two thermistors using a micro-electromechanical system (MEMS) process on a flexible polyimide film. The thermistors were connected to a Wheatstone bridge circuit, and the resistance difference between the thermistors resulting from the generation of a flow was converted into an output voltage signal using LabVIEW software. A mini tube flow test was conducted to demonstrate the sensor’s detection of fluid velocity in gas and liquid flows. A good correlation was found between the experimental results and the simulation data. However, the results for the gas and liquid flows differed in that for gas, the output voltage increased with the fluid’s velocity and decreased against the liquid’s flow velocity. This study’s MEMS-based flexible microthermal flow sensor achieved a resolution of 1.1 cm/s in a liquid flow and 0.64 cm/s in a gas flow, respectively, within a fluid flow velocity range of 0–40 cm/s. The sensor is suitable for many applications; however, with some adaptations to its electrical packaging, it will be particularly suitable for detecting biosignals in healthcare applications, including measuring respiration and body fluids.

scholarly journals Finite Element Method Simulation and Characterization of a Thermal Flow Sensor Based on Printed Circuit Board Technology for Various Fluids

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 833 ◽  
Author(s):  
Thomas Glatzl ◽  
Roman Beigelbeck ◽  
Samir Cerimovic ◽  
Harald Steiner ◽  
Albert Treytl
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Printed Circuit Board ◽  
Flow Sensor ◽  
Circuit Board ◽  
Thermal Flow ◽  
Fem Simulations ◽  
Printed Circuit ◽  
Thermal Flow Sensor ◽  
Element Method

We present finite element method (FEM) simulations of a thermal flow sensor as well as a comparison to measurement results. The thermal sensor is purely based on printed circuit board (PCB) technology, designed for heating, ventilation, and air conditioning (HVAC) systems. Design and readout method of the sensor enables the possibility to measure the flow velocity in various fluids. 2D-FEM simulations were carried out in order to predict the sensor characteristic of envisaged setups. The simulations enable a fast and easy way to evaluate the sensor’s behaviour in different fluids. The results of the FEM simulations are compared to measurements in a real environment, proving the credibility of the model.

scholarly journals Detection and Localization of Interference and Useful Signal Extreme Points in Closely Coupled Multiconductor Transmission Line Networks

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1209 ◽  
Author(s):  
Gazizov ◽  
Gazizov ◽  
Gazizov
Keyword(s):  
Pulse Duration ◽  
Ultrashort Pulse ◽  
Autonomous Navigation ◽  
Printed Circuit Board ◽  
Extreme Points ◽  
Circuit Board ◽  
Interference Signal ◽  
Peak Voltage ◽  
Useful Signal ◽  
Detection And Localization

This study highlights the importance of detecting and localizing useful and interference signal extreme points in multiconductor transmission lines (MCTL) by developing a new approach for detecting and localizing signal extreme points in MCTL networks of arbitrary complexity. A radio-electronic component is presented as a network consisting of a number of connected MCTL sections. Each MCTL section is divided into segments and the number of segments is set by the user. The approach is based on a quasi-static calculation of signal waveforms at any point (segment) along each conductor of an MCTL. The block diagrams of the developed algorithms are presented. Using the approach, a number of investigations have been done which include the following: the signal maximum detection and localization in the meander lines with one and two turns, the influence of ultrashort pulse duration on localization of its extreme points in the printed circuit board (PCB) bus of a spacecraft autonomous navigation system, the influence of ultrashort pulse duration on localization of crosstalk extreme points in the PCB bus, and the simulation of electrostatic discharge effects on the PCB bus. There are also some investigations with optimization methods presented. A genetic algorithm (GA) was used to optimize the influence of ultrashort pulse duration on localization of the pulse and crosstalk extreme points in the PCB bus. Furthermore, the GA was used to optimize the PCB bus loads by criteria of the peak voltage minimization. A similar investigation was carried out with the evolution strategy. The obtained results help us to argue that the signal extreme points can be detected both in structures with different configurations and applying different excitations.

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