Design and Test of a MEMS Accelerometer Array for Submarine Landslide Displacement Monitoring

2021 ◽  
Vol 55 (1) ◽  
pp. 5-16
Author(s):  
Yongqiang Ge ◽  
Jiawang Chen ◽  
Chen Cao ◽  
Jiamin He ◽  
Yan Sheng ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Integrated Circuit ◽  
Slope Failure ◽  
Circuit Board ◽  
Measurement Unit ◽  
Physical Model Test ◽  
Submarine Landslides ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
The Difference

AbstractSubmarine landslides in gas hydrate areas are a significant geo-hazard that can cause considerable damage. The processes and mechanism of submarine landslides caused by gas hydrate dissociation are not clearly understood. Therefore, we designed a micro-electro-mechanical systems (MEMS) accelerometer array to study and monitor the deep displacement of submarine landslides. The MEMS accelerometer array consists of several gravity acceleration-sensing units that are protected and positioned using a flexible circuit board and elastic steel tape, such that all the units are connected to an Inter-Integrated Circuit (IIC) communication bus. By sensing the three-axis tilt angles, the direction and magnitude of the displacement for a measurement unit can be calculated; then, the overall displacement of the array is calculated as the difference in the displacements from the initial values. To ensure the accuracy of the tilt angle and displacement calculation, the calibration and verification test of the single MEMS sensor and sensor array is conducted. The MEMS accelerometer array is verified with respect to its principle and arrangement by a laboratory physical model test, and the initial experimentation demonstrated the capacities of the monitoring system for collecting real-time and in-situ information about the dynamic process and propagation of slope failure.

A New Type of Device Used on Submarine Landslides Monitoring

2020 ◽  
Author(s):  
Yongqiang Ge ◽  
Jiawang Chen ◽  
Chen Cao ◽  
Qiaoling Gao ◽  
Peihao Zhang ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Slope Failure ◽  
Measurement Unit ◽  
Laboratory Model ◽  
Landslide Monitoring ◽  
Submarine Landslides ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
New Type ◽  
Gravity Acceleration

Abstract Submarine landslides in gas hydrate areas are a significant geo-hazard that can cause considerable damage to offshore infrastructures, dramatically change the marine environment and seriously threaten human lives and property. Gas and gas hydrate disassociation was considered to be a main factor inducing submarine landslide. However, the processes and mechanism of submarine landslides caused by gas and gas hydrate dissociation are not clearly understood. Therefore, we design a Micro-Electro-Mechanical Systems (MEMS) accelerometer array to study and monitor the deep displacement of submarine landslides. The MEMS accelerometer array consists of several gravity acceleration-sensing units that are connected to an I2C-communication bus. By sensing the three-axis tilt angles, the direction and magnitude of the displacement for a measurement unit can be calculated. In the end, the laboratory model test was designed to verify the operation of the device in landslide monitoring, which demonstrated the capacities of the monitoring system for collecting real-time and in-situ information during the slope failure.

scholarly journals Elevated Standoff Heights of Solder Joint Interconnections Can Result in Appreciable Stress and Warpage Relief

2019 ◽  
Vol 16 (1) ◽  
pp. 13-20
Author(s):  
Ephraim Suhir ◽  
Sung Yi ◽  
Jennie S. Hwang ◽  
Reza Ghaffarian
Keyword(s):  
Solder Joint ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Calculated Data ◽  
Circuit Board ◽  
Stress Model ◽  
Solder Material ◽  
The Difference ◽  
Ic Package

Abstract The “head-in-pillow” (HnP) defects in lead-free solder joint interconnections of Integrated Circuit (IC) packages with conventional (small) standoff heights of the solder joints, and particularly in packages with fine pitches, are attributed by many electronic material scientists to the three major causes: attributes of the manufacturing process, solder material properties, and design-related issues. The latter are thought to be caused primarily by elevated stresses in the solder material, as well as by the excessive warpage of the Printed Circuit Board (PCB)-package assembly and particularly by the differences in the thermally induced curvatures of the PCB and the package. In this analysis, the stress and warpage issue is addressed using an analytical predictive stress model. The model is a modification and an extension of the model developed back in 1980s by the first author. It is assumed that it is the difference in the postfabrication deflections of the PCB-package assembly that is the root cause of the solder material failures and particularly and perhaps the HnP defects. The calculated data based on the developed stress model suggest that the replacement of the conventional ball grid array (BGA) designs with designs with elevated standoff heights of the solder joints could result in significant stress and warpage relief and, hopefully, in a lower propensity of the IC package to HnP defects as well. The general concepts are illustrated by a numerical example, in which the responses to the change in temperature of a conventional design, referred to as BGA, and a design with solder joints with elevated standoff heights, referred to as column grid array (CGA), are compared. The computed data indicated that the effective stress in the solder material was relieved by about 40% and the difference between the maximum deflections of the PCB and the package was reduced by about 60%, when the BGA design was replaced by a CGA system. Although no definite proof that the use of solder joints with elevated standoff heights will lessen the package propensity to the HnP defects is provided, the authors nonetheless think that there is a reason to believe that the application of solder joints with elevated standoff heights could result in a substantial improvement in the general IC package performance, including, perhaps, its propensity to HnP defects.

scholarly journals Dating submarine landslides using the transient response of gas hydrate stability

2021 ◽  
Author(s):  
Alexey Portnov ◽  
Kehua You ◽  
Peter Flemings ◽  
Ann Cook ◽  
Mahdi Heidari ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Slope Failure ◽  
Conductive Heat ◽  
Submarine Landslides ◽  
Conductive Heat Flow ◽  
Submarine Slides ◽  
Orca Basin ◽  
Bottom Simulating Reflection ◽  
3D Seismic Data ◽  
Hydrate Stability

Abstract Submarine landslides are prevalent on the modern-day seafloor, yet an elusive problem is constraining the timing of slope failure. Herein, we present a novel technique for constraining the age of submarine landslides without sediment core dating. Underneath a submarine landslide in the Orca Basin, Gulf of Mexico, in 3D seismic data we map an irregular bottom simulating reflection (BSR), which mimics the geometry of the pre-slide seafloor rather than the modern bathymetry. Based on the observed BSR, we suggest that the gas hydrate stability zone (GHSZ) is currently adjusting to the post-slide sediment temperature perturbations. We apply transient conductive heat flow modeling to constrain the response of the GHSZ to the slope failure, which yields a most likely age of ~8 ka demonstrating that gas hydrate systems can respond to slope failures even on the millennia timescales. We also provide an analytical approach to rapidly determine the age of submarine slides at any location.

scholarly journals The Research on a Driving Device for Natural Gas Hydrate Pressure Core

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 221
Author(s):  
Ziqiang Ren ◽  
Jiawang Chen ◽  
Qiaoling Gao ◽  
Peihao Zhang ◽  
Kai He ◽  
...  
Keyword(s):  
Natural Gas ◽  
Natural Frequency ◽  
Gas Hydrate ◽  
Natural Gas Hydrate ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
Lead Screw ◽  
Drilling Tools ◽  
The Stability ◽  
Core Part

Precise pressure core motion, including translation and rotation, is the basis and core part of the Analysis and Transfer System of Natural Gas Hydrate Pressure Core, which is crucial to nondestructive analyses, core cutting, and transfer. This paper mainly proposes a driving device, whereby a pressure core, up to 3 m long, can be transferred from pressure core drilling tools to proceed to nondestructive analyses and transferring the cores into other chambers. The lead screw is one of the most important components of this driving device. Therefore, the modal analyses of the lead screw are performed, which can help researchers to analyze the stability of this device. The analyzed data shows that the different positions of the slider have a great impact on the natural frequency of the lead screw. Furthermore, the lead screw with a support slider has a larger natural frequency than that without a support slider. According to data analysis, we can derive that the device with the support slider has a much larger rigidity, which can contribute to the stability of the device. To verify the feasibility of this device, the deformation of the lead screw was tested by the Micro-Electro-Mechanical Systems (MEMS) accelerometer array. Experimental results show that the deformation of the lead screw with the support slider is much less than that without the support slider.

State of the Art Substrate Manipulation as a Tool for Enhancing Product Performance

2011 ◽  
Author(s):  
Michael A. Gonzales ◽  
Jose Cabanillas
Keyword(s):  
Integrated Circuit ◽  
Uv Light ◽  
Turnaround Time ◽  
Product Performance ◽  
Circuit Board ◽  
Conformal Coating ◽  
Root Cause ◽  
Light Curing ◽  
The Difference ◽  
Ic Package

Abstract Substrate modifications on the Integrated Circuit (IC) package provide opportunities for the Failure Analyst (FA) to troubleshoot a routing failure or allow a design engineer to create new routing possibilities for a prototype device. The results can mean the difference in finding the root cause of the problem and being early or late to market. This paper describes a variety of methods to open sections of the package circuit board to access and cut I/O traces interwoven throughout the package substrate. It also describes the use of conductive epoxies for connecting traces, vias and solders bumps. Restoring the solder mask with an ultraviolet (UV) light curing conformal coating is also discussed. This method was used to characterize ground sensitivities and simulate inductance effects on the package. The flexibility and fast turnaround time this method enables has already enhanced product performance.

Stiffness Measurement of Micro-Cantilever Based on Negative Electrostatic Stiffness

2020 ◽  
Vol 12 (1) ◽  
pp. 96-100
Author(s):  
Xianshan Dong ◽  
Qinwen Huang ◽  
Yun Huang ◽  
Wei Su ◽  
Ping Lai
Keyword(s):  
Basic Structure ◽  
Mems Devices ◽  
Mechanical Stiffness ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
Mems Sensor ◽  
The Difference ◽  
Micro Cantilever ◽  
Fabrication Variation ◽  
Non Destructive

Micro-cantilever is basic structure of Micro-Electro-Mechanical-Systems (MEMS) sensor, and mechanical stiffness is the most important parameter of micro-cantilever. The mechanical stiffness can be affected by shape, size and material, and it should be experimentally measured for fabrication variation. Yet, the micro scale of MEMS cantilever makes the measurement difficult, and the traditional method isn't suitable for the micro-cantilever. This study proposes a new method for measuring the mechanical stiffness of micro-cantilever, and measurement of MEMS accelerometer was also experimentally carried out. The proposed method exploits the feature that the voltage applied on cantilever can lead to negative electrostatic stiffness, and this stiffness can change the deformation of cantilever. The mechanical stiffness can be obtained through analyzing the change of output. Results from this study coincided with our theoretical model, and the difference between results obtained by this method and SEM was 2.2%. This work provides a new way to precisely obtain mechanical stiffness of micro-cantilever using non-destructive method, making it helpful for researchers to design micro-cantilever and MEMS devices.

Application of Lock-in Thermography on PCB for Fault Localization and Validation of Failure Mechanism Due to External Discrete Component Variation

2010 ◽  
Author(s):  
William Ng ◽  
Kevin Weaver ◽  
Zachary Gemmill ◽  
Herve Deslandes ◽  
Rudolf Schlangen
Keyword(s):  
Failure Mechanism ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Hot Spot ◽  
Circuit Board ◽  
Discrete Component ◽  
Printed Circuit ◽  
Thermal Signature ◽  
Lock In

Abstract This paper demonstrates the use of a real time lock-in thermography (LIT) system to non-destructively characterize thermal events prior to the failing of an integrated circuit (IC) device. A case study using a packaged IC mounted on printed circuit board (PCB) is presented. The result validated the failing model by observing the thermal signature on the package. Subsequent analysis from the backside of the IC identified a hot spot in internal circuitry sensitive to varying value of external discrete component (inductor) on PCB.

scholarly journals Experimental Study of the Space–Time Effect of a Double-Pipe Frozen Curtain Formation with Different Groundwater Velocities

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3830
Author(s):  
Shicheng Sun ◽  
Chuanxin Rong ◽  
Hua Cheng ◽  
Bin Wang ◽  
Xiaogang Jiang ◽  
...  
Keyword(s):  
Freezing Temperature ◽  
Physical Model Test ◽  
Sand Layer ◽  
Test Results ◽  
Groundwater Velocity ◽  
Test Platform ◽  
The Difference ◽  
Freezing Test ◽  
Double Pipe ◽  
Thermal Physical Properties

Groundwater velocity has significant effects on the formation of a frozen curtain during freezing. In order to study the influence of the velocity on a frozen curtain, a large physical model test platform was established for double-pipe freezing. Based on this platform, freezing tests for different velocities were carried out. Quartz sand was selected as a similar material. The freezing temperature of the saturated sand layer was found by analyzing the results of the nuclear magnetic resonance (NMR). Based on the study of the thermal physical properties of the sand layer, the freezing test results were analyzed, and the results showed that the flow led to the differential development of the temperature between the upstream and downstream sections of the freezing pipes. Moreover, the larger the velocity, the greater the difference. The flow prolonged the overlapping time of the frozen curtains. Additionally, the flow slowed down the development of the frozen curtain area and the frozen curtain thickness. The larger the flow velocity, the greater the inhibition of the flow on the development of the frozen curtain. The test results can provide more references for the design and construction of freezing engineering with flowing groundwater.

Evolution of Stress During Formation of Titanium Disilicide by Rta and Tube Furnace Annealing

1990 ◽  
Vol 202 ◽  
Author(s):  
J.F. Jongste ◽  
O.B. Loopstra ◽  
G.C.A.M. Janssen ◽  
S. Radelaar
Keyword(s):  
Integrated Circuit ◽  
Thermal Processing ◽  
Reaction Rates ◽  
Titanium Disilicide ◽  
Furnace Annealing ◽  
Integrated Circuit Fabrication ◽  
Annealing Step ◽  
Circuit Fabrication ◽  
The Difference ◽  
Processing Steps

Integrated circuit fabrication consists of many processing steps: e.g. lithography, etching, implantation and metallization. Some of these processes are combined with thermal processing. Heat treatments require special attention because previous fabrication steps may be influenced: e.g. dopant profiles may be deteriorated. The amount of interference of an annealing step with a former process is determined by the ratio of the reaction rates (and hence by the difference in activation energies).

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