Finite element modeling of residual mechanical stress in partial SOI structure due to wafer bonding processing

2004 ◽  
Author(s):  
Guangyu Huang ◽  
Cher Ming Tan ◽  
Zhenghao Gan ◽  
Wei Jun ◽  
Guan Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Mechanical Stress ◽  
Wafer Bonding ◽  
Element Modeling ◽  
Residual Mechanical Stress

Finite Element Modeling of Vocal Fold Vibration in Normal Phonation and Hyperfunctional Dysphonia: Implications for the Pathogenesis of Vocal Nodules

1998 ◽  
Vol 107 (7) ◽  
pp. 603-610 ◽  
Author(s):  
Jack J. Jiang ◽  
Carlos E. Diaz ◽  
David G. Hanson
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Mechanical Stress ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Element Modeling ◽  
Modeling Technology ◽  
Vocal Fold Vibration ◽  
Vocal Nodules ◽  
High Mechanical Stress

A computer model of the vocal fold was developed using finite element modeling technology for studying mechanical stress distribution over vibrating vocal fold tissue. In a simulated normal phonation mode, mechanical stress was found to be lowest at the midpoint of the vocal fold and highest at tendon attachments. However, when other modes predominated, high mechanical stress could occur at the midpoint of the vocal folds. When a vocal fold mass was modeled, high shearing stress occurred at the base of the modeled vocal fold mass, suggesting that the presence of a vocal nodule or polyp is associated with high mechanical stress at the margins of the mass. This finding supports a hypothesis that mechanical intraepithelial stress plays an important role in the development of vocal nodules, polyps, and other lesions that are usually ascribed to hyperfunctional dysphonia.

Development of Integrated Process-Ageing Modeling Methodology for Flip Chip on Flex Interconnections With Non-Conductive Adhesives

2005 ◽  
Author(s):  
Xiaowu Zhang ◽  
E. H. Wong ◽  
Ranjan Rajoo ◽  
Mahadevan K. Iyer ◽  
J. F. J. M. Caers ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Mechanical Stress ◽  
Flip Chip ◽  
Process Condition ◽  
Integrated Process ◽  
Conductive Adhesives ◽  
Element Modeling ◽  
Ageing Test ◽  
Modeling Methodology

This paper presents a comprehensive methodology to model the static temperature-humidity (TH) ageing test (85°C/85%RH over 1000 hours) of flip chip on flex interconnections with non-conductive adhesives (NCAs). Nonconductive adhesives, being a special form of conductive adhesives, are chosen, as they allow bringing the pitch further down. The methodology combines experimental techniques for material characterization, finite element modeling (FEM) and model validation. A non-conductive adhesive (NCA) has been characterized using several techniques. The thermomechanical properties and the moisture properties were obtained for the NCA. A temperature dependent viscoelastic constitutive model was also obtained for the NCA. The viscoelastic model was defined by the Prony series expansion. The shift factor was approximated by the Williams-Landel-Ferry (WLF) equation. Finite element modeling has been performed to analyze the flip chip interconnects on flex with the NCA under process condition and reliability ageing conditions. The viscoelastic constitutive relation has been used to model the NCA in ageing modeling. An integrated process-ageing modeling methodology has been developed to combine the thermo-mechanical stress and hygro-mechanical stress, followed by stress relaxation analysis. To verify the finite element models, the static TH ageing test (85°C/85%RH) were also performed. The contact resistance was monitored with high measuring resolution during the accelerated test. The simulation results are good agreement with the experimental results. The approach developed in this paper can be used to provide guidelines with respect to adhesive material properties, assembly process parameters and good reliability performances.

Exact First Order Finite Element Modeling for Eddy Current NDE

1991 ◽  
Vol 3 (1) ◽  
pp. 235-253 ◽  
Author(s):  
L. D. Philipp ◽  
Q. H. Nguyen ◽  
D. D. Derkacht ◽  
D. J. Lynch ◽  
A. Mahmood
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Eddy Current ◽  
Element Modeling ◽  
First Order ◽  
Eddy Current Nde

Tire Vibration Modes and Effects on Vehicle Ride Quality

1993 ◽  
Vol 21 (1) ◽  
pp. 23-39 ◽  
Author(s):  
R. W. Scavuzzo ◽  
T. R. Richards ◽  
L. T. Charek
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Operating Conditions ◽  
Modal Testing ◽  
Ride Quality ◽  
Vibration Modes ◽  
Inflation Pressure ◽  
Passenger Cars ◽  
Element Modeling ◽  
Road Surfaces

Abstract Tire vibration modes are known to play a key role in vehicle ride, for applications ranging from passenger cars to earthmover equipment. Inputs to the tire such as discrete impacts (harshness), rough road surfaces, tire nonuniformities, and tread patterns can potentially excite tire vibration modes. Many parameters affect the frequency of tire vibration modes: tire size, tire construction, inflation pressure, and operating conditions such as speed, load, and temperature. This paper discusses the influence of these parameters on tire vibration modes and describes how these tire modes influence vehicle ride quality. Results from both finite element modeling and modal testing are discussed.

Evolving the Banded Radial Tire

1987 ◽  
Vol 15 (1) ◽  
pp. 30-41 ◽  
Author(s):  
E. G. Markow
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Finite Element Modeling ◽  
Laboratory Tests ◽  
Rolling Resistance ◽  
Two Dimensional ◽  
Theoretical Discussion ◽  
Radial Tire ◽  
Puncture Resistance ◽  
Element Modeling

Abstract Development of the banded radial tire is discussed. A major contribution of this tire design is a reliable run-flat capability over distances exceeding 160 km (100 mi). Experimental tire designs and materials are considered; a brief theoretical discussion of the mechanics of operation is given based on initial two-dimensional studies and later on more complete finite element modeling. Results of laboratory tests for cornering, rolling resistance, and braking are presented. Low rolling resistance, good cornering and braking properties, and low tread wear rate along with good puncture resistance are among the advantages of the banded radial tire designs.

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