Modeling Vibration Induced Fatigue Failure of Free Standing Wire Bonds

Abstract Wire bonds are used to connect device terminals to package terminals or substrate terminal that forms circuits that are needed to create desired higher level functions. If a wire bond breaks or becomes detached during operation, the desired function will be lost. Depending on the design, a loss in function could be catastrophic. Aluminum, gold, and copper wires are used to create wire bonds in electronic products. These materials have been selected for their ability to be formed as fine wires and their ability to provide low electrical resistance. In many electronics packages, wire bonds are encapsulated in a polymer molding compound that is used to protect the electronic device. However, in some electronic devices such as hermetically sealed cavity packages, wire bonds may be free-standing. Under vibration loading, free-standing wire bonds may be subject to failure due to mechanical fatigue. In this work, an analytic model is presented for predicting natural frequency of a free-standing wire bond and for assessing a wire bond time to failure under a harmonic loading condition. The model for natural frequency is calibrated by finite element analysis and validated through experimental testing. The life prediction model, a test plan, and preliminary test results are presented.

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Dynamic Properties of Delaminated Braided Textile Composite Beams

Volume 1: Advanced Energy Systems; Advanced and Digital Manufacturing; Advanced Materials; Aerospace ◽

10.1115/esda2008-59462 ◽

2008 ◽

Author(s):

Benjamin Dauda ◽

S. Olutunde Oyadiji ◽

Prasad Potluri

Keyword(s):

Natural Frequency ◽

Vibration Analysis ◽

Natural Frequencies ◽

Dynamic Properties ◽

Experimental Testing ◽

Composite Beams ◽

Textile Composite ◽

Element Analysis ◽

Frequency Shifts ◽

Cantilevered Beams

In this paper, vibration analysis of through-width single- and multi-delaminated cantilevered composite beams is carried out using Finite Element Analysis (FEA) approach. Different configurations of multiple delaminations are considered. The FEA results for single delaminations are validated via experimental testing. It is found that changes in the natural frequencies of delaminated cantilevered beams are related to the number, type and distributions of delaminations within a beam. Also, the natural frequency shifts due to single or multiple delaminations are influenced by the thickness-wise locations of the delaminations. As the delamination is moved from the outermost inter-laminar layer towards the mid-plane of the beam, the natural frequency decreases and reaches a minimum value when the delamination is located at the midplane. Single delaminations have a more significant effect on natural frequencies than multiple delaminations of the same overall dimension as the single delamination. Furthermore, it is found that there is a greater reduction in natural frequency when multiple delaminations are close together than when they are spread out. However, where the locations of multiple delaminations coincide with nodal or antinodal vibration points, the effect is significantly altered.

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Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation

Materials ◽

10.3390/ma14020314 ◽

2021 ◽

Vol 14 (2) ◽

pp. 314

Author(s):

Miroslav Pástor ◽

Martin Hagara ◽

Ivan Virgala ◽

Adam Kaľavský ◽

Alžbeta Sapietová ◽

...

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Experimental Testing ◽

Digital Processing ◽

Image Correlation ◽

Optical Systems ◽

Hole Drilling ◽

Element Analysis ◽

Thin Specimen ◽

Comparison Of The Results

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

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The Finite Element Analysis and Optimization for the Grinder Based on the Joint Surface

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.281.165 ◽

2013 ◽

Vol 281 ◽

pp. 165-169 ◽

Cited By ~ 1

Author(s):

Xiang Lei Zhang ◽

Bin Yao ◽

Wen Chang Zhao ◽

Ou Yang Kun ◽

Bo Shi Yao

Keyword(s):

Finite Element ◽

Natural Frequency ◽

Element Model ◽

Joint Surface ◽

Weak Links ◽

Response Analysis ◽

Element Analysis ◽

Static And Dynamic Analysis ◽

Harmonic Response Analysis ◽

Grinding Machine

Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.

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On-Site Experimental Testing to Study the Vibration of Composite Floors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.601.231 ◽

2014 ◽

Vol 601 ◽

pp. 231-234

Author(s):

Cristian Lucian Ghindea ◽

Dan Cretu ◽

Monica Popescu ◽

Radu Cruciat ◽

Elena Tulei

Keyword(s):

Dynamic Characteristics ◽

Experimental Testing ◽

Concrete Slab ◽

Human Perception ◽

Experimental Tests ◽

International Standards ◽

Structural Element ◽

Element Analysis ◽

Floor Slabs ◽

Composite Floors

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.

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Residual Stress Measurement and Simulation of 3C-SiC Single and Poly Crystal Cantilevers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.865 ◽

2010 ◽

Vol 645-648 ◽

pp. 865-868 ◽

Cited By ~ 3

Author(s):

Ruggero Anzalone ◽

Massimo Camarda ◽

Daniel Alquier ◽

M. Italia ◽

Andrea Severino ◽

...

Keyword(s):

Experimental Data ◽

Theoretical Study ◽

Stress Measurement ◽

Bulk Material ◽

Raman Shift ◽

Silicon Substrates ◽

Free Standing ◽

Element Analysis ◽

Micro Fabrication ◽

Sic Films

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication. In this work a comparison between single crystal and poly crystal 3C-SiC micro-machined structures will be presented. The free-standing structures realized (cantilevers and membrane) are also a suitable method for residual field stress investigation in 3C-SiC films. Measurement of the Raman shift indicates that the mono and poly-crystal 3C-SiC structures release the stress in different ways. Finite element analysis was performed to determine the stress field inside the films and provided a good fit to the experimental data. A comprehensive experimental and theoretical study of 3C-SiC MEMS structures has been performed and is presented.

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Fatigue crack detection in pipes with multiple mode nonlinear guided waves

Structural Health Monitoring ◽

10.1177/1475921718791134 ◽

2018 ◽

Vol 18 (1) ◽

pp. 180-192 ◽

Cited By ~ 13

Author(s):

Ruiqi Guan ◽

Ye Lu ◽

Kai Wang ◽

Zhongqing Su

Keyword(s):

Fatigue Crack ◽

Crack Detection ◽

Guided Waves ◽

Second Harmonic ◽

Experimental Testing ◽

Harmonic Wave ◽

Guided Wave ◽

Element Analysis ◽

Fatigue Crack Detection ◽

Wave Modes

This study elaborates fundamental differences in fatigue crack detection using nonlinear guided waves between plate and pipe structures and provides an effective approach for analysing nonlinearity in pipe structures. For this purpose, guided wave propagation and interaction with microcrack in a pipe structure, which introduced a contact acoustic nonlinearity, was analysed through a finite element analysis in which the material nonlinearity was also included. To validate the simulation results, experimental testing was performed using piezoelectric transducers to generate guided waves in a specimen with a fatigue crack. Both methods revealed that the second harmonic wave generated by the breathing behaviour of the microcrack in a pipe had multiple wave modes, unlike the plate scenario using nonlinear guided waves. Therefore, a proper index which considered all the generated wave modes due to the microcrack was developed to quantify the nonlinearity, facilitating the identification of microscale damage and further assessment of the severity of the damage in pipe structures.

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Design of an Air-Cooled Radial Turbine: Part 1 — Computational Modelling

Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines ◽

10.1115/gt2018-76378 ◽

2018 ◽

Cited By ~ 2

Author(s):

Yang Zhang ◽

Tomasz Duda ◽

James A. Scobie ◽

Carl M. Sangan ◽

Colin D. Copeland ◽

...

Keyword(s):

Numerical Simulation ◽

Experimental Testing ◽

Temperature Drop ◽

Computational Modelling ◽

Operating Conditions ◽

Inlet Temperature ◽

Topology Optimisation ◽

Internal Cooling ◽

Element Analysis ◽

Radial Turbine

This paper is part of a two-part publication that aims to design, simulate and test an internally air cooled radial turbine. To achieve this, the additive manufacturing process, Selective Laser Melting (SLM), was utilized to allow internal cooling passages within the blades and hub. This is, to the authors’ knowledge, the first publication in the open literature to demonstrate an SLM manufactured, cooled concept applied to a small radial turbine. In this paper, the internally cooled radial turbine was investigated using a Conjugate Heat Transfer (CHT) numerical simulation. Topology Optimisation was also implemented to understand the areas of the wheel that could be used safely for cooling. In addition, the aerodynamic loss and efficiency of the design was compared to a baseline non-cooled wheel. The experimental work is detailed in Part 2 of this two-part publication. Given that the aim was to test the rotor under representative operating conditions, the material properties were provided by the SLM technology collaborator. The boundary conditions for the numerical simulation were derived from the experimental testing where the inlet temperature was set to 1023 K. A polyhedral unstructured mesh made the meshing of internal coolant plenums including the detailed supporting structures possible. The simulation demonstrated that the highest temperature at the blade leading edge was 117 K lower than the uncooled turbine. The coolant mass flow required by turbine was 2.5% of the mainstream flow to achieve this temperature drop. The inertia of the turbine was also reduced by 20% due to the removal of mass required for the internal coolant plenums. The fluid fields in both the coolant channels and downstream of the cooled rotor were analyzed to determine the aerodynamic influence on the temperature distribution. Furthermore, the solid stress distribution inside the rotor was analyzed using Finite Element Analysis (FEA) coupled with the CFD results.

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Design, Kinematics and Prototype of a Flexible Robot Arm With Planar Springs

Volume 5A: 39th Mechanisms and Robotics Conference ◽

10.1115/detc2015-46503 ◽

2015 ◽

Cited By ~ 2

Author(s):

Peng Qi ◽

Hongbin Liu ◽

Lakmal Seneviratne ◽

Kaspar Althoefer

Keyword(s):

Preliminary Test ◽

Industrial Applications ◽

Robot Arm ◽

Kinematic Modeling ◽

Flexible Robot ◽

Element Analysis ◽

Robot Arms ◽

Environmental Interactions ◽

In Series ◽

Fea Simulation

Flexible robot arms have been developed for various medical and industrial applications because of their compliant structures enabling safe environmental interactions. This paper introduces a novel flexible robot arm comprising a number of elastically deformable planar spring elements arranged in series. The effects of flexure design variations on their layer compliance properties are investigated. Numerical studies of the different layer configurations are presented and finite Element Analysis (FEA) simulation is conducted. Based on the suspended platform’s motion of each planar spring, this paper then provides a new method for kinematic modeling of the proposed robot arm. The approach is based on the concept of simultaneous rotation and the use of Rodrigues’ rotation formula and is applicable to a wide class of continuum-style robot arms. At last, the flexible robot arms respectively integrated with two different types of compliance layers are prototyped. Preliminary test results are reported.

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Computational Process Simulation and Energy Parameter Analysis From Mechanical Deformation of Aerospace Alunimum Alloys

Recent Advances in Solids and Structures ◽

10.1115/imece2002-39290 ◽

2002 ◽

Author(s):

James M. Fragomeni ◽

Giridhar Venugopal

Keyword(s):

Yield Strength ◽

Experimental Testing ◽

True Strain ◽

Energy Parameter ◽

True Stress ◽

Parameter Analysis ◽

Dissipated Energy ◽

Strain Hardening Exponent ◽

Element Analysis ◽

Buckling Strength

Many systems that work on the processing of energy can be modeled in terms of that energy. The energy that is given to the system may be stored or dissipated in the form of heat. It was proposed to extend this concept to attainment of critical level of stored energy and/or dissipated energy for occurrence of buckling of a metal column under compressive loading. The fact that Energy Factor Parameter (E.F.P.) computed from the experimental true stress-true strain values, suddenly decreased and approached value close to zero indicated either buckling and/or softening, but deviated with the E.F.P. computed from the theoretical true stress and true strain values. The 7050-T7451 (Al-Zn-Mg-Cu-Zr) and Al-Li-Cu aluminum alloys in longitudinal and transverse grain orientations were compression tested for mechanical properties of yield strength, buckling strength, strength coefficient, strain hardening exponent. Correlation between ratio of buckling strength and yield strength with aging time for preaged ASTM compression specimens was established. The compression deformation of aluminum alloy 7050 was modeled using finite element analysis, with the experimental testing parameters and the database in the software package.

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