Wear of a Tool in Double-Disk Lapping of Silicon Wafers

2010 ◽  
Author(s):  
Adam Barylski ◽  
Mariusz Deja
Keyword(s):  
Experimental Data ◽  
Integrated Circuits ◽  
Tool Wear ◽  
Silicon Wafers ◽  
Silicon Ingot ◽  
Proposed Model ◽  
Tool Wear Prediction ◽  
Simulation Results ◽  
High Degree ◽  
Kinematical Parameters

Silicon wafers are the most widely used substrates for fabricating integrated circuits. A sequence of processes is needed to turn a silicon ingot into silicon wafers. One of the processes is flattening by lapping or by grinding to achieve a high degree of flatness and parallelism of the wafer [1, 2, 3]. Lapping can effectively remove or reduce the waviness induced by preceding operations [2, 4]. The main aim of this paper is to compare the simulation results with lapping experimental data obtained from the Polish producer of silicon wafers, the company Cemat Silicon from Warsaw (www.cematsil.com). Proposed model is going to be implemented by this company for the tool wear prediction. Proposed model can be applied for lapping or grinding with single or double-disc lapping kinematics [5, 6, 7]. Geometrical and kinematical relations with the simulations are presented in the work. Generated results for given workpiece diameter and for different kinematical parameters are studied using models programmed in the Matlab environment.

A Simplified Numerical Approach to Characterize the Thermal Response of a Moving Bed Solar Reactor

2021 ◽  
Author(s):  
Assaad Al Sahlani ◽  
Kelvin Randhir ◽  
Nesrin Ozalp ◽  
James Klausner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Energy Storage ◽  
Solid Particle ◽  
Gas Flow ◽  
Plug Flow ◽  
Fixed Bed ◽  
Flow Rates ◽  
Proposed Model ◽  
Simulation Results

Abstract Concentrated solar thermochemical storage in the form of a zero-emission fuel is a promising option to produce long-duration energy storage. The production of solar fuel can occur within a cylindrical cavity chemical reactor that captures concentrated solar radiation from a solar field. A heat transfer model of a tubular plug-flow reactor is presented. Experimental data from a fixed bed tubular reactor are used for model comparison. The system consists of an externally heated tube with counter-current flowing gas and moving solid particles as the heated media. The proposed model simulates the dynamic behavior of temperature profiles of the tube wall, gas, and particles under various gas flow rates and residence times. The heat transfer between gas-wall, solid particle-wall, gas-solid particle, are numerically studied. The model is compared with experiments using a 4 kW furnace with a 150 mm heating zone surrounding a horizontal alumina tube (reactor) with 50.8 mm OD and a thickness of 3.175 mm. Solid fixed particles of magnesium manganese oxide (MgMn2O4) with the size of 1 mm are packed within the length of 250 mm at the center of the tube length. Simulation results are assessed with respect to fixed bed experimental data for four different gas flow rates, namely 5, 10, 15, 20 standard liters per minute of air, and furnace temperatures in the range of 200 to 1200 °C. The simulation results showed good agreement with maximum steady state error that is less than 6% of those obtained from the experiments among all runs. The proposed model can be implemented as a low-order physical model for the control of temperature inside plug-flow reactors for thermochemical energy storage (TCES) applications.

scholarly journals Internal Stability Evaluation of Soils

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1439
Author(s):  
Qingfeng Feng ◽  
Hao-Che Ho ◽  
Teng Man ◽  
Jiaming Wen ◽  
Yuxin Jie ◽  
...  
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Numerical Model ◽  
Internal Stability ◽  
Combined Effects ◽  
Stability Evaluation ◽  
Major Threat ◽  
Satisfactory Performance ◽  
Proposed Model ◽  
Simulation Results

Suffusion constitutes a major threat to the foundation of a dam, and the likelihood of suffusion is always determined by the internal stability of soils. It has been verified that internal stability is closely related to the grain size distribution (GSD) of soils. In this study, a numerical model is developed to simulate the suffusion process. The model takes the combined effects of GSD and porosity (n) into account, as well as Wilcock and Crowe’s theory, which is also adopted to quantify the inception and transport of soils. This proposed model is validated with the experimental data and shows satisfactory performance in simulating the process of suffusion. By analyzing the simulation results of the model, the mechanism is disclosed on how soils with specific GSD behaving internally unstable. Moreover, the internal stability of soils can be evaluated through the model. Results show that it is able to distinguish the internal stability of 30 runs out of 36, indicating a 83.33% of accuracy, which is higher than the traditional GSD-based approaches.

Numerical Study on Turbulence Modification in Particle-Laden Pipe Flows

2011 ◽  
Vol 130-134 ◽  
pp. 3603-3606
Author(s):  
Fu Sheng Yan ◽  
Wei Jun Zhang ◽  
Ru Quan Liang
Keyword(s):  
Experimental Data ◽  
Turbulent Flows ◽  
Pipe Flow ◽  
Numerical Study ◽  
Vertical Pipe ◽  
Pipe Flows ◽  
Dilute Gas ◽  
Turbulence Modification ◽  
Proposed Model ◽  
Simulation Results

This investigation deals with the study on the processes involved in the phenomenon about turbulence modification in dilute gas-particle turbulent flows. The proposed model, along with other selected turbulence modification models from the literature, is used to simulate a particle-laden vertical pipe flow. The simulation results show that the new model provides improved predictions of the experimental data.

A SIMPLIFIED NUMERICAL APPROACH TO CHARACTERIZE THE THERMAL RESPONSE OF A MOVING BED SOLAR REACTOR

2021 ◽  
pp. 1-6
Author(s):  
Assaad Alsahlani ◽  
Kelvin Randhir ◽  
Nesrin Ozalp ◽  
James Klausner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Solid Particle ◽  
Gas Flow ◽  
Plug Flow ◽  
Fixed Bed ◽  
Tube Length ◽  
Flow Rates ◽  
Proposed Model ◽  
Simulation Results

Abstract In this paper, heat transfer model of a tubular plug-flow reactor designed and manufactured for a solar fuel production is presented. Experimental data collected from a fixed bed tubular reactor testing are used for model comparison. The system consists of an externally heated tube with counter-current flowing gas and moving solid particles as the heated media. The proposed model simulates the dynamic behavior of temperature profiles of the tube wall, gas, and particles under various gas flow rates and residence times. The heat transfer between gas-wall, solid particle-wall, and gas-solid particle are numerically studied. The model results are compared with the results of experiments done using a 4 kW furnace with a 150 mm heating zone surrounding a horizontal alumina tube (reactor) with 50.8 mm outer diameter and thickness of 3.175 mm. Solid fixed particles of MgMn2O4 with the size of 1 mm are packed within length of 250 mm at the center of the tube length. Simulation results are assessed with respect to fixed bed experimental data for four different gas flow rates, namely 5, 10, 15, 20 standard liters per minute of air, and furnace temperatures in the range of 200 to 1200 °C. The simulation results showed good agreement with maximum steady state error that is less than 6% of those obtained from the experiments for all runs. The proposed model can be implemented as a low-order physical model for the control of temperature inside plug-flow reactors.

Research on the Rice Leaf Morphological Formation and its Visualization

2011 ◽  
Vol 201-203 ◽  
pp. 2504-2508
Author(s):  
Hong Wei Liu ◽  
Yan Yang Liang ◽  
Hui Zhang
Keyword(s):  
Experimental Data ◽  
Growth Process ◽  
Leaf Morphology ◽  
Leaf Growth ◽  
Morphological Characteristics ◽  
Biological Parameters ◽  
Rice Leaf ◽  
Proposed Model ◽  
Simulation Results ◽  
The Mathematical Model

This paper firstly summarizes the morphological characteristics of rice leaf through observation of the rice leaf growth process. And then the mathematical model of the rice leaf growing is established based on experimental data. In this model, the vectorization of rice leaf morphology and growth process is realized by only several explicit biological parameters. The visualization of the rice leaf growth process is realized in computer by technique of computer graphics and the combination of VC++ and OpenGL. The simulation results show that the proposed model can simulate the growth process of the rice leaf very well on the computer easily with less parameter.

Preparation of integrated circuits for TEM electromigration in situ studies

1986 ◽  
Vol 44 ◽  
pp. 882-883
Author(s):  
J. V. Maskowitz ◽  
W. E. Rhoden ◽  
D. R. Kitchen ◽  
R. E. Omlor ◽  
P. F. Lloyd
Keyword(s):  
Integrated Circuits ◽  
Crystallographic Orientation ◽  
Silicon Wafers ◽  
Minimum Size ◽  
Test Vehicle ◽  
In Situ Studies ◽  
Boron Doped ◽  
Doped Silicon ◽  
Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

BEHAVIORAL MODEL OF A LINEAR VOLTAGE STABILIZER IN THE SPICE LANGUAGE

2019 ◽  
Author(s):  
Aleksey Malahanov
Keyword(s):  
Experimental Data ◽  
Behavioral Model ◽  
Voltage Stabilizer ◽  
Static Mode ◽  
Technical Description ◽  
Simulation Results ◽  
Chip Manufacturer ◽  
Linear Voltage

A variant of the implementation of the behavioral model of a linear voltage stabilizer in the Spice language is presented. The results of modeling in static mode are presented. The simulation results are compared with experimental data and technical description of the chip manufacturer.

Dual Release Model to Evaluate Dissolution Profiles from Swellable Drug Polyelectrolyte Matrices

2020 ◽  
Vol 17 (6) ◽  
pp. 511-522 ◽  
Author(s):  
Alicia Graciela Cid ◽  
María Verónica Ramírez-Rigo ◽  
María Celeste Palena ◽  
Elio Emilio Gonzo ◽  
Alvaro Federico Jimenez-Kairuz ◽  
...  
Keyword(s):  
Experimental Data ◽  
Drug Release ◽  
Inflection Point ◽  
Release Profile ◽  
Experimental Point ◽  
Extended Model ◽  
Release Process ◽  
Proposed Model ◽  
Dual Release ◽  
Release Model

Background: Mathematical modeling in modified drug release is an important tool that allows predicting the release rate of drugs in their surrounding environment and elucidates the transport mechanisms involved in the process. Objective: The aim of this work was to develop a mathematical model that allows evaluating the release profile of drugs from polymeric carriers in which the swelling phenomenon is present. Methods: Swellable matrices based on ionic complexes of alginic acid or carboxymethylcellulose with ciprofloxacin were prepared and the effect of adding the polymer sodium salt on the swelling process and the drug release was evaluated. Experimental data from the ciprofloxacin release profiles were mathematically adjusted, considering the mechanisms involved in each stage of the release process. Results: A proposed model, named “Dual Release” model, was able to properly fit the experimental data of matrices presenting the swelling phenomenon, characterized by an inflection point in their release profile. This entails applying the extended model of Korsmeyer-Peppas to estimate the percentage of drug released from the first experimental point up to the inflection point and then a model called Lumped until the final time, allowing to adequately represent the complete range of the drug release profile. Different parameters of pharmaceutical relevance were calculated using the proposed model to compare the profiles of the studied matrices. Conclusion: The “Dual Release” model proposed in this article can be used to predict the behavior of complex systems in which different mechanisms are involved in the release process.

scholarly journals Electrostatic Discharge Characteristics of SiGe Source/Drain PNN Tunnel FET

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 454
Author(s):  
You Wang ◽  
Yu Mao ◽  
Qizheng Ji ◽  
Ming Yang ◽  
Zhaonian Yang ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Computer Aided Design ◽  
Field Effect ◽  
Electrostatic Discharge ◽  
Field Effect Transistors ◽  
Test Method ◽  
Current Path ◽  
Simulation Results ◽  
Current Characteristics ◽  
Aided Design

Gate-grounded tunnel field effect transistors (ggTFETs) are considered as basic electrostatic discharge (ESD) protection devices in TFET-integrated circuits. ESD test method of transmission line pulse is used to deeply analyze the current characteristics and working mechanism of Conventional TFET ESD impact. On this basis, a SiGe Source/Drain PNN (P+N+N+) tunnel field effect transistors (TFET) was proposed, which was simulated by Sentaurus technology computer aided design (TCAD) software. Simulation results showed that the trigger voltage of SiGe PNN TFET was 46.3% lower, and the failure current was 13.3% higher than Conventional TFET. After analyzing the simulation results, the parameters of the SiGe PNN TFET were optimized. The single current path of the SiGe PNN TFET was analyzed and explained in the case of gate grounding.

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