Design and Experiment of Thermal Contact Sensor Detecting Defects on Si Wafer Surface

2012 ◽  
Vol 523-524 ◽  
pp. 826-831 ◽  
Author(s):  
Wen Jian Lu ◽  
Yuki Shimizu ◽  
So Ito ◽  
Wei Gao
Keyword(s):  
Temperature Rise ◽  
Thermal Contact ◽  
Fem Simulation ◽  
Element Model ◽  
Frictional Heat ◽  
Wafer Surface ◽  
Sensor Element ◽  
Type Contact ◽  
Contact Sensor ◽  
Si Wafer

A deign study of a thermal-type contact sensor for the detection of small defects, the heights of which are less than 16 nm on the wafer surface, is described in this paper. The feasibility of the contact sensor, which would detect frictional heat generated at the contact with defects, was theoretically investigated focusing on the temperature rise of the sensor element. To investigate the temperature rise of the contact sensor due to the generated frictional heat, both the theoretical calculation with simple model of heat transfer and a simulation with a finite element model (FEM) was carried out. Relationship between the sensor size and the response of the temperature rise of the contact sensor was also investigated by using FEM simulation.

New Measurement Concept of Nanometer-Level Defects on Si Wafer Surface by Using Micro Contact Sensor

2012 ◽  
Vol 497 ◽  
pp. 137-141 ◽  
Author(s):  
Wen Jian Lu ◽  
Yuki Shimizu ◽  
Wei Gao
Keyword(s):  
Temperature Rise ◽  
Electric Circuit ◽  
Frictional Heat ◽  
Wafer Surface ◽  
Fem Model ◽  
Element Simulation ◽  
Type Contact ◽  
Contact Sensor ◽  
Measurement Concept ◽  
Si Wafer

A thermal-type contact sensor was proposed to detect small defects, the heights of which are less than 16 nm, on the wafer surface. The feasibility of the contact sensor, which detects frictional heat generated at the contact, was theoretically investigated focusing on the temperature rise of the sensor element. Simulation results with both the simple model of heat transfer and the FEM model showed that the expected temperature rise of the contact sensor is enough to be detected by the conventional electric circuit.

scholarly journals Development of a Micro-Sized Thermal Contact Sensor for Inspection of Surface Defects

2013 ◽  
Vol 7 (6) ◽  
pp. 708-713 ◽  
Author(s):  
Yuki Shimizu ◽  
◽  
Wenjian Lu ◽  
Yuta Ohba ◽  
Wei Gao
Keyword(s):  
Relative Velocity ◽  
Surface Defects ◽  
Thermal Contact ◽  
Target Surface ◽  
Frictional Heat ◽  
Contact Detection ◽  
Film Resistance ◽  
Pzt Actuator ◽  
Contact Sensor ◽  
Micro Sphere

This paper presents an experimental study on a thermal element, which is designed to be used as a sensing device that detects a small amount of frictional heat due to a contact with nanometre-scale defects on smoothly-finished surfaces. A prototype of the thermal element, which is a thin-film resistance, is fabricated by using photolithography processes, and its sensitivity on the contact detection is investigated through some experiments, in which the thermal element is scratched by a micro-sphere controlled by PZT actuator in both X- and Z-directions so that a contact between the thermal element and defects can be simulated. Influences of an interference height and relative velocity between the thermal element and the target surface on the output of the thermal element at the contact detection are verified.

A Multiphysics Finite Element Model of a 35A Automotive Connector Including Multiscale Rough Surface Contact

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Santosh V. Angadi ◽  
Robert L. Jackson ◽  
Song-yul Choe ◽  
George T. Flowers ◽  
Bong-Yi Lee ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Rough Surface ◽  
Temperature Rise ◽  
Thermal Contact ◽  
Element Model ◽  
Electrical Contacts ◽  
Contact Method ◽  
Surface Contact ◽  
Rough Surface Contact

Electrical contacts influence the reliability and performance of relays, electrical connectors, high power connectors, and similar systems, and are therefore a key region which needs to be considered. In the current study, a new inclusive multiphysics (involving mechanical, electrical, and thermal fields) finite element model (FEM) of a 35A automotive connector has been developed. The contact resistance is predicted using a multiscale rough surface contact method and is embedded in the multiphysics FEM. The coupled connector model is solved to obtain stresses, displacements, contact pressures, electrical and thermal contact resistances, voltage, current density, and temperature distributions. It appears that the current flows mostly through very small regions that are usually near the contacting surfaces in the connector, thereby suggesting that the available conducting material can be more efficiently used by developing optimized connector designs. Through analytical calculations and experimental measurements of temperature rise (ΔT or change in temperature) for the cable and the connector, it is believed that a large portion of the temperature rise in actual 35A connectors is due to the Joule heating in the supply cables. The model is a powerful tool that can be used for the basic connector characterization, prototype evaluation, and design through various material properties, and surface finishes.

A Study on Statistical Analysis of Si-Wafer Polishing Process for the Optimum Polishing Condition

2008 ◽  
Vol 389-390 ◽  
pp. 493-497 ◽  
Author(s):  
Sung Chul Hwang ◽  
Jong Koo Won ◽  
Jung Taik Lee ◽  
Eun Sang Lee
Keyword(s):  
Surface Roughness ◽  
Statistical Analysis ◽  
Process Parameters ◽  
Wafer Surface ◽  
Wafer Polishing ◽  
Ultra Precision ◽  
Important Processing ◽  
The Many ◽  
Selection Of ◽  
Si Wafer

As the level of Si-wafer surface directly affects device line-width capability, process latitude, yield, and throughput in fabrication of microchips, it needs to have ultra precision surface and flatness. Polishing is one of the important processing having influence on the surface roughness in manufacturing of Si-wafers. The surface roughness in wafer polishing is mainly affected by the many process parameters. For decreasing the surface roughness, the control of polishing parameters is very important. In this paper, the optimum condition selection of ultra precision wafer polishing and the effect of polishing parameters on the surface roughness were evaluated by the statistical analysis of the process parameters.

scholarly journals Observation of Oxide-film Step with Very Small Height on Si Wafer Surface Using a Laser Scattering Method

2006 ◽  
Vol 72 (11) ◽  
pp. 1363-1367
Author(s):  
Haruyuki INOUE ◽  
Toshihiko KATAOKA ◽  
Yoshihiro NAGAO ◽  
Yasushi OSHIKANE ◽  
Motohiro NAKANO ◽  
...  
Keyword(s):  
Oxide Film ◽  
Wafer Surface ◽  
Scattering Method ◽  
Laser Scattering ◽  
Small Height ◽  
Si Wafer

Thermal Effects Due to Surface Films in Sliding Contact

1994 ◽  
Vol 116 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Brian Vick ◽  
L. P. Golan ◽  
M. J. Furey
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Effects ◽  
Three Dimensional ◽  
Sliding Contact ◽  
Frictional Heat ◽  
Solution Technique ◽  
Surface Films ◽  
Thermal Coupling ◽  
Efficient Manner

The present work examines theoretically the influence of surface coatings on the temperatures produced by friction due to sliding contact. A generalized thermal model is developed which incorporates three-dimensional, transient heat transfer between layered media with thermal coupling at multiple, interacting contact patches. A solution technique based on a variation of the boundary element method is developed and utilized. The method allows for the solution of the distribution of frictional heat and the resulting temperature rise in an accurate yet numerically efficient manner. Results are presented showing the influence of film thickness, thermal properties, velocity, and contact area on the division of heat and surface temperature rise. The results show that a film with thermal properties different than those of the substrate can have a pronounced effect on the predicted temperature rise.

Wear Based Lifetime Estimation of a Clutch Facing using Coupled Field Analysis

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
A. Kulkarni ◽  
R. Mahale ◽  
C. Kannan
Keyword(s):  
Working Life ◽  
Element Model ◽  
Friction Material ◽  
Inorganic Materials ◽  
Field Analysis ◽  
Frictional Heat ◽  
Ride Quality ◽  
Wear Loss ◽  
Limiting Factor ◽  
The Impact

Repetitive use of the clutch, over a period of time, causes the friction material at the contact surfaces (clutch facing and flywheel/pressure plate) to wear, thus deteriorating its performance and usable life. The working life of a rigid clutch is the limiting factor when it comes to extracting maximum performance from a dual mass flywheel system, which is used in a lot of modern vehicles nowadays to lower fuel consumption and improve ride quality. In this study, we investigate the influence of different groove patterns on wear in rigid clutch facings and estimate their life using a comprehensive finite element model. The wear is calculated and analysed for five different groove patterns across two different inorganic materials, namely FTL180 and TF1600-MC2, using Archard’s Adhesive Wear Model. Coupled multi-physics elements are employed in the analysis to capture the effect of frictional heat generation on wear. We found that the Waffle pattern offered a decrease of 10.4% in volumetric wear loss, a 5.78% decrease in maximum wear thickness and an increase of 11.51% in the average working life is used in city like conditions with frequent engagements. This work sheds light on the impact of groove patterns on clutch facing wear and opens a new path for the design and development of more resilient rigid clutches.

scholarly journals Focality of the Induced E-Field Is a Contributing Factor in the Choice of TMS Parameters: Evidence from a 3D Computational Model of the Human Brain

2020 ◽  
Vol 10 (12) ◽  
pp. 1010
Author(s):  
Deepika Konakanchi ◽  
Amy L. de Jongh Curry ◽  
Robert S. Waters ◽  
Shalini Narayana
Keyword(s):  
Spatial Distribution ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Element Model ◽  
Brain Areas ◽  
Invasive Approach ◽  
Non Invasive ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact

Transcranial magnetic stimulation (TMS) is a promising, non-invasive approach in the diagnosis and treatment of several neurological conditions. However, the specific results in the cortex of the magnitude and spatial distribution of the secondary electrical field (E-field) resulting from TMS at different stimulation sites/orientations and varied TMS parameters are not clearly understood. The objective of this study is to identify the impact of TMS stimulation site and coil orientation on the induced E-field, including spatial distribution and the volume of activation in the cortex across brain areas, and hence demonstrate the need for customized optimization, using a three-dimensional finite element model (FEM). A considerable difference was noted in E-field values and distribution at different brain areas. We observed that the volume of activated cortex varied from 3000 to 7000 mm3 between the selected nine clinically relevant coil locations. Coil orientation also changed the induced E-field by a maximum of 10%, and we noted the least optimal values at the standard coil orientation pointing to the nose. The volume of gray matter activated varied by 10% on average between stimulation sites in homologous brain areas in the two hemispheres of the brain. This FEM simulation model clearly demonstrates the importance of TMS parameters for optimal results in clinically relevant brain areas. The results show that TMS parameters cannot be interchangeably used between individuals, hemispheres, and brain areas. The focality of the TMS induced E-field along with its optimal magnitude should be considered as critical TMS parameters that should be individually optimized.

The Study on the Surface Abrasion about Wafer Final Polishing

2009 ◽  
Vol 626-627 ◽  
pp. 147-152
Author(s):  
Jong Koo Won ◽  
Jung Taik Lee ◽  
Eun Sang Lee
Keyword(s):  
Study Design ◽  
Temperature Sensor ◽  
Processing Time ◽  
Processing Condition ◽  
Major Influence ◽  
Wafer Surface ◽  
Head Unit ◽  
Wafer Polishing ◽  
Machining Speed ◽  
Si Wafer

Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafer. This study will report the evaluation on abrasion of wafer according to processing time; machining speed and pressure which have major influence on the abrasion of Si wafer polishing, for this, this study design the head unit and analysis head unit. After that, apply to experiment. It is possible to evaluation of wafer abrasion by load cell and infrared temperature sensor. The evaluation of abrasion according to processing condition is selected to use result data that measure a pressure, machining speed, and the processing time. This result is appeared by abrasion in machining condition. Through that, the study cans evaluation a wafer abrasion in machining. It is important to obtain mirror-like wafer surface.

Analytical Modeling and Experimental Validation of Heating at the Leaf Seal/Rotor Interface

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Michael J. Pekris ◽  
Gervas Franceschini ◽  
Andrew K. Owen ◽  
Terry V. Jones ◽  
David R. H. Gillespie
Keyword(s):  
Mass Flow Rate ◽  
Analytical Model ◽  
Mass Flow ◽  
Flow Rate ◽  
Temperature Rise ◽  
Thermal Characteristic ◽  
Frictional Heat ◽  
Test Facility ◽  
Engine Operation ◽  
Secondary Air

The secondary air system of a modern gas or steam turbine is configured to satisfy a number of requirements, such as to purge cavities and maintain a sufficient flow of cooling air to key engine components, for a minimum penalty on engine cycle efficiency and specific fuel consumption. Advanced sealing technologies, such as brush seals and leaf seals, are designed to maintain pressures in cavities adjacent to rotating shafts. They offer significant reductions in secondary air parasitic leakage flows over the legacy sealing technology, the labyrinth seal. The leaf seal comprises a series of stacked sheet elements which are inclined relative to the radial direction, offering increased axial rigidity, reduced radial stiffness, and good leakage performance. Investigations into leaf seal mechanical and flow performance have been conducted by previous researchers. However, limited understanding of the thermal behavior of contacting leaf seals under sustained shaft contact has led to the development of an analytical model in this study, which can be used to predict the power split between the leaf and rotor from predicted temperature rises during operation. This enables the effects of seal and rotor thermal growth and, therefore, implications on seal endurance and rotor mechanical integrity to be quantified. Consideration is given to the heat transfer coefficient in the leaf pack. A dimensional analysis of the leaf seal problem using the method of extended dimensions is presented, yielding the expected form of the relationship between seal frictional power generation, leakage mass flow rate, and rotor temperature rise. An analytical model is derived which is in agreement. Using the derived leaf temperature distribution formula, the theoretical leaf tip temperature rise and temperature distributions are computed over a range of mass flow rates and frictional heat values. Experimental data were collected in high-speed tests of a leaf seal prototype using the Engine Seal Test Facility at Oxford University. These data were used to populate the analytical model and collapsed well to confirm the expected linear relationship. In this form, the thermal characteristic can be used with predictions of mass flow rate and frictional power generated to estimate the leaf tip and rotor temperature rise in engine operation.

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